Document:

<PAGE>

                                                       EXHIBIT NUMBER (10)(xiii)
                                                       TO 2000 FORM 10-K

                           181 WEST MADISON BUILDING

                                  LEASE WITH

                          THE NORTHERN TRUST COMPANY
                                    TENANT

                                 LEASING AGENT

                DOUGLAS ELLIMAN-BEITLER MANAGEMENT CORPORATION
                            181 West Madison Street
                                  Suite 3900
                            Chicago, Illinois 60602

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<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<S>                                                                                                           <C>
1.    LEASE OF PREMISES; DEFINITIONS.........................................................................  2

2.    TERM...................................................................................................  6

3.    RENT...................................................................................................  6

4.    OPERATING EXPENSES.....................................................................................  9

5.    HOLDING OVER........................................................................................... 18

6.    USE.................................................................................................... 18

7.    LANDLORD'S SERVICES AND OBLIGATIONS.................................................................... 19

8.    TENANT'S OBLIGATIONS................................................................................... 22

9.    RIGHTS RESERVED TO LANDLORD............................................................................ 28

10.   TELEPHONE, ELECTRIC AND OTHER SERVICES................................................................. 31

11.   LANDLORD'S TITLE....................................................................................... 31

12.   QUIET ENJOYMENT........................................................................................ 31

13.   LIMIT ON WAIVER OF CERTAIN CLAIMS...................................................................... 31

14.   CONDITION OF PREMISES AND LANDLORD'S WORK.............................................................. 32

15.   TERMINATION............................................................................................ 32

16.   ASSIGNMENT AND SUBLETTING.............................................................................. 33

17.   UNTENANTABILITY........................................................................................ 36

18.   DEFAULTS; CONDITIONS LIMITATIONS; REMEDIES............................................................. 38

19.   EMINENT DOMAIN......................................................................................... 44

20.   SUBORDINATION AND SUPERIORITY OF THIS LEASE............................................................ 44
</TABLE>
<PAGE>

<TABLE>
<S>                                                                                                           <C>
21.   SPRINKLERS............................................................................................  45

22.   LANDLORD'S MAINTENANCE................................................................................  45

23.   NOTICE................................................................................................  46

24.   SUCCESSORS AND ASSIGNS................................................................................  46

25.   INSURANCE.............................................................................................  47

26.   MISCELLANEOUS.........................................................................................  49

27.   ESTOPPEL CERTIFICATES.................................................................................  52

28.   MORTGAGEE PROTECTION..................................................................................  52

29.   LANDLORD'S COMPLIANCE WITH LAW........................................................................  53

30.   INDEMNIFICATION BY TENANT.............................................................................  54

31.   INDEMNIFICATION BY LANDLORD...........................................................................  55

32.   POSSESSION............................................................................................  55

33.   EXONERATION CLAUSE....................................................................................  55

34.   WAIVER OF JURY TRIAL..................................................................................  56

35.   LANDLORD DEFAULT AND PERFORMANCE BY TENANT............................................................  56

36.   MOST FAVORED TENANT...................................................................................  57

37.   PEDESTRIAN BRIDGE.....................................................................................  58

38.   MONUMENT SIGNAGE......................................................................................  59

39.   LOBBY SIGNAGE.........................................................................................  59

40.   RIGHTS PERSONAL TO TENANT.............................................................................  59

41.   FIRST EXTENSION OPTION................................................................................  60

42.   SECOND EXTENSION OPTION...............................................................................  61
</TABLE>
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<TABLE>
<S>                                                                                                          <C>
43.   MARKET RATE...........................................................................................  62

44.   ELEVATOR TRANSFER.....................................................................................  63

45.   CONTRACTION OPTION....................................................................................  63

46.   RIGHT OF FIRST OFFER UPON SALE OF THE BUILDING........................................................  65

47.   NAME OF THE BUILDING..................................................................................  66

48.   PUT SPACE.............................................................................................  67

49.   ALLOWANCE FOR EXTENSION PREMISES......................................................................  69

50.   TERMINATION OF EXISTING LEASE.........................................................................  69

51.   RIGHT OF FIRST OFFER TO LEASE.........................................................................  71

52.   EXPANSION SPACE.......................................................................................  74

53.   PARKING...............................................................................................  77

54.   BACK UP GENERATOR.....................................................................................  78

55.   KITCHEN FACILITIES....................................................................................  78

EXHIBIT A   Plan of Premises................................................................................  A-1

EXHIBIT B   Rentable Area...................................................................................  B-2

EXHIBIT C   Rules and Regulations...........................................................................  C-1

EXHIBIT D   Cleaning Specifications.........................................................................  D-1

EXHIBIT E   Tenant Lease Estoppel Certificate...............................................................  E-1

EXHIBIT F   Legal Description...............................................................................  F-1

EXHIBIT G   ["Intentionally Deleted"].......................................................................  G-1

EXHIBIT H   Base Rent.......................................................................................  H-1
</TABLE>
<PAGE>

<TABLE>
<S>                                                                                                           <C>
EXHIBIT I   Items to be Removed.............................................................................   I-1

EXHIBIT J   Payment of Rent Adjustment......................................................................   J-1

EXHIBIT K   Example of Calculation of Special Tenant Fee....................................................   K-1

EXHIBIT L   Stacking Plan 181 West Madison Stacking Plan....................................................   L-1

EXHIBIT M   Level Pay.......................................................................................   M-1

EXHIBIT N   Short Form of Lease.............................................................................   N-1

EXHIBIT O   Form of First Offer Notice......................................................................   O-1

EXHIBIT P   Landlord's Work.................................................................................   P-1

EXHIBIT Q   Parking Space Location..........................................................................   Q-1
</TABLE>
<PAGE>

                                     LEASE

                                      FOR

                           181 WEST MADISON BUILDING

     THIS LEASE (this "Lease") is made  and entered into at Chicago, Illinois,
as of the 29th day of November, 2000, by and between LASALLE BANK NATIONAL
          ----        --------
ASSOCIATION, as successor trustee to American National Bank and Trust Company of
Chicago, not individually, but solely and only as Trustee under a certain Trust
Agreement (the "Trust Agreement") dated the 5/th/ day of April, 1990, and known
as Trust Number 110513-07 (the "Landlord"), and THE NORTHERN TRUST COMPANY, an
Illinois banking corporation (the "Tenant"), as follows:

                                   RECITALS
                                   --------

     A.  American National Bank and Trust Company of Chicago, as Trustee under
Trust No. 65287 ("Prior Landlord") and Tenant entered into that certain Lease
dated August 28, 1985 (the "Original Lease") as amended by that certain First
Amendment to Agreement of Lease dated August 15, 1986 (the "First Amendment"),
that certain Second Amendment to Agreement of Lease dated August 6, 1987 (the
"Second Amendment"), and that certain Third Amendment to Agreement of Lease
dated May 20, 1988 (the "Third Amendment").

     B.  The Original Lease, as amended by the First Amendment, Second Amendment
and Third Amendment, was assigned by Prior Landlord to Landlord by an assignment
dated April 6, 1990.

     C.  Landlord and Tenant further amended the Original Lease by that certain
Fourth Amendment to Agreement of Lease dated May 1, 1990 ("Fourth Amendment"),
that certain Fifth Amendment to Agreement of Lease dated January 12, 1995, that
certain Sixth Amendment to Agreement of Lease dated November 30, 1995 ("Sixth
Amendment") that certain Seventh Amendment dated February 24, 1998, that certain
Eighth Amendment to Lease dated January 31, 2000, that certain Ninth Amendment
to Lease dated January 31, 2000 ("Ninth Amendment"), that certain Tenth
Amendment to Lease dated February 1, 2000, ("Tenth Amendment") that certain
Eleventh Amendment to Lease dated August 1, 2000, ("Eleventh Amendment") and
that certain Twelfth Amendment to Lease dated August 28, 2000, (Twelfth
Amendment).  The Original Lease, as amended, is hereinafter referred to as the
"Existing Lease."

     D.  Pursuant to the Existing Lease, Tenant leased the Extension Premises
(as defined in Section 1B) and the 23/rd/ floor of the Building from Landlord,
totally approximately 284,296 rentable square feet  in the Building, and the
36/th/ floor, containing 20,866 square feet of Rentable Area (collectively, the
"Existing Premises").

                                       1
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     E.  Landlord and Tenant have agreed to terminate the Existing Lease and
enter into a new lease of the Premises for a longer term, on the terms and
conditions of this Lease.

     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants
contained herein, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Landlord and Tenant agree as
follows:

1.   LEASE OF PREMISES; DEFINITIONS.

     A.  The Landlord hereby leases to the Tenant and the Tenant hereby accepts
the lease of the premises consisting of that certain office space on Exhibit A
and incorporated herein by reference (the "Premises") located in the office
building (the "Building") located on the real estate commonly known as 181 WEST
MADISON BUILDING, located at 181 West Madison Street, Chicago, Illinois, the
legal description of which is attached hereto as Exhibit F and incorporated
herein by reference (the "Real Estate").  The Building and the Real Estate
together with the vehicular drives, the above and below ground parking
facilities, and all other structures and improvements now or hereinafter located
upon the Real Estate are hereinafter sometimes collectively referred to as the
"Property".  Rentable Area of the Premises is deemed to be as shown on Exhibit
A.  A stacking plan of the Building showing Rentable Area per floor is attached
as Exhibit L.

     B.  The following terms shall have the following meanings wherever used in
this Lease:

         (i)    "Affiliate" shall have the meaning set forth in Section 16.

         (ii)   "Alterations" shall have the meaning set forth in Section 8J.

         (iii)  "Special Tenant Fee" shall have the meaning set forth in
                Section 3D.

         (iv)   "Base Rent" shall have the meaning set forth in Section 3A.

         (v)    "Building" shall have the meaning set forth in Section 1A.

         (vi)   "Calculation Year" shall have the meaning set forth in
                Section 4A(vi).

         (vii)  "Commencement Date" shall have the meaning set forth in
                Section 2.

         (viii) "Default Rate" shall have the meaning set forth in Section
                3F.

         (ix)   "Deficiency" shall have the meaning set forth in Section 18F.

         (x)    "Employee" means an officer, director, employee, partner,
                contractor,  subcontractor, or representative.

                                       2
<PAGE>

       (xi)     "Existing Lease" shall have the meaning set forth in Recital
                C.

       (xii)    "Existing Premises" shall have the meaning set forth in
                Recital D.

       (xiii)   "Expansion Space" shall have the meaning set forth in
                Section 52.

       (xiv)    "Extension Premises" means the following space identified
                on Exhibit A: floors 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15 (Suite
                1500, Suite 1550), Suite 1600 on the 16th floor, 20.

       (xv)     "First Offer Space" shall have the meaning set forth in Section
                51.

       (xvi)    "Fiscal Year" shall have the meaning set forth in Section 3D.

       (xvii)   "Fiscal Year Tax and Expense Amount" shall have the meaning set
                forth in Section 3D.

       (xviii)  "Government Entity" means the United States, the State of
                Illinois, the City of Chicago, and any and every other agency,
                department, commission, rule-making body, bureau,
                instrumentality, and/or political subdivision of government of
                any kind whatsoever, now existing or hereafter created, now or
                hereafter having jurisdiction over the Premises, the Building,
                and/or the use, occupancy, possession, operation and/or
                maintenance of the Premises and/or the Building.

       (xix)    "Indemnitee" means Landlord, Landlord's Affiliates, and Rental
                Agent.

       (xx)     "Landlord" shall have the meaning set forth in the opening
                paragraph and in Section 24.

       (xxi)    "Landlord's Affiliates" means:

                (a)  any Person controlling Landlord and any Person controlling
                     the same;

                (b)  any Person controlled by Landlord and any Person controlled
                     by the same;

                (c)  any Person under common control with Landlord;

                (d)  any Person which acquires substantially all of the assets
                     of Landlord or any corporation into which Landlord may be
                     merged or with which Landlord may be consolidated;

                                       3
<PAGE>

                (e)  any Person who is a beneficiary under the Trust Agreement,
                     any Person controlling or controlled by, or under common
                     control with, such a beneficiary, and any Person
                     controlling or controlled by the same; and

                (f)  all Employees of Landlord and of every Person referred to
                     in (a), (b), (c), (d) and (e) above.

                     For purposes of this definition, "control" means the direct
              or indirect ownership of more than twenty percent (20%) of the
              common stock of a corporation or the direct or indirect beneficial
              ownership of an unincorporated enterprise.

     (xxii)    "Landlord's Work" shall have the meaning set forth in Exhibit P.

     (xxiii)   "Law" or "Laws" means each and every law, rule, regulation,
               order, ordinance, statute, requirement, code or executive mandate
               of any kind whatsoever, present or future, issued by any
               Government Entity applicable to or affecting the Premises and/or
               the Property, and/or the use, occupancy, possession, operation,
               and/or maintenance of the Premises and/or the Property.

     (xxiv)    "Lease" shall have the meaning set forth in the opening
               paragraph.

     (xxv)     "Lease Termination Notice" shall have the meaning set forth in
               Section 18B(i).

     (xxvi)    "Lease Year" shall have the meaning set forth in Section 4A(i).

     (xxvii)   "Legal Proceeding" means every action, litigation, summary
               proceeding, arbitration, administrative proceeding, and other
               legal or equitable proceeding of any kind whatsoever.

     (xxviii)  "Market Rental Rate" shall have the meaning set forth in Section
               43.

     (xxix)    "Operating Expense Deposit" shall have the meaning set forth in
               Section 4A(v).

     (xxx)     "Operating Expenses" shall have the meaning set forth in Section
               4A(iii).

     (xxxi)    "Person" means an individual person, corporation, partnership,
               trust, joint venture, proprietorship, estate or other
               incorporated or unincorporated enterprise, entity, or
               organization of any kind whatsoever.

                                       4
<PAGE>

     (xxxii)   "Possession Termination Notice" shall have the meaning set forth
               in Section 18B(ii).

     (xxxiii)  "Premises" shall have the meaning set forth in Section 1.

     (xxxiv)   "Prime Rate" shall have the meaning set forth in Section 3C.

     (xxxv)    "Put Space" shall have the meaning set forth in Section 48.

     (xxxvi)   "Property" shall have the meaning set forth in Section 1.

     (xxxvii)  "Real Estate" shall have the meaning set forth in Section 1.

     (xxxviii) "Rent" shall have the meaning set forth in Section 3.

     (xxxix)   "Rent Adjustment" shall have the meaning set forth in Section 3.

     (xl)      "Rental Agent" shall have the meaning set forth in Section 3.

     (xli)     "Rentable Area" for each full office floor in the Building from
               floors 4 through 38, both inclusive, is shown on Exhibit B, as
               agreed to by Tenant and Landlord. If "Rentable Area" is stated in
               the Lease for a partial floor then, that area shall be deemed
               agreed to by Landlord and Tenant. "Rentable Area" for partial
               floors which may be leased by Tenant in the Building and which
               are not specifically set forth in this Lease shall be determined
               pursuant to the Standard Method for Measuring Floor Area in
               Office Buildings published by the Building Owners and Managers
               Association International approved June 7, 1996, by American
               National Standards Institute, Inc., or other more recent issuance
               of such standards. Rentable Area does not equal useable area.

     (xlii)    "RSF" shall mean, as the context requires, one square foot or a
               number of square feet of Rentable Area in any given space.

     (xliii)   "Superior Encumbrance" means the following:

               (a)  any and every mortgage or trust deed now a lien, or
                    hereafter becoming a lien, upon the Building, Real Estate or
                    Property, or any part thereof;

               (b)  any lease presently or hereafter in effect between Landlord,
                    as lessee or tenant, and any fee owner of the Building, Real
                    Estate or Property; and

                                       5
<PAGE>

               (c)  any amendment, modification, or consolidation of the
                    foregoing, and all liens securing any further advances made
                    in connection with the foregoing.

     (xliv)    "Tax and Expense Cap" shall have the meaning set forth in Section
               3D.

     (xlv)     "Tax and Expense Component" shall have the meaning set forth in
               Section 3D.

     (xlvi)    "Taxes" shall have the meaning set forth in Section 4A(iv).

     (xlvii)   "Tenant" shall have the meaning set forth in the opening
               paragraph.

     (xlviii)  "Tenant's Proportionate Share" shall have the meaning set forth
               in Section 4A(ii).

     (xlix)    "Tenant's Work" means all Alterations, and any repairs,
               maintenance, decorations or improvements which Tenant is
               obligated to perform under this Lease.

     (l)       "Term" shall have the meaning set forth in Section 2.

     (li)      "Trust Agreement" shall have the meaning set forth in the opening
               paragraph.

     (lii)     "23/rd/ Floor" shall mean that portion of the Premises located on
               the 23rd Floor, when used to identify a portion of the Premises.

     (liii)    "include" or "including" shall be construed as meaning to
               include, or including, "but not limited to" or "without
               limitation".

2.  TERM. The Term of this Lease commences on the 1st day of December, 2000 (the
"Commencement Date") and ends on the last day of December 31, 2020 (the "Term"),
unless sooner terminated or extended as hereinafter provided.

3.  RENT. Tenant will pay to Landlord's rental agents, DOUGLAS ELLIMAN-BEITLER
MANAGEMENT CORPORATION, (the "Rental Agents") at 181 West Madison Street, Suite
3900, Chicago, Illinois 60602, or to such other persons or at such other places
as the Landlord may direct from time to time by written notice to the Tenant, in
coin or currency or wire transfer of good funds which at the time of payment is
legal tender for the payment of public and private debts in the United States of
America, without setoff, recoupment or deduction whatsoever and, without demand

                                       6
<PAGE>

or billing, except as hereinafter provided, the aggregate of the following, all
of which are hereby declared to be "Rent".

     A.  Base Rent (hereinafter defined), payable in advance in equal monthly
installments each promptly on the first day of each and every calendar month
during the Term of this Lease. "Base Rent" shall mean the sum of the amounts for
each twelve month period during the Term of this Lease calculated for each
portion of the Premises by multiplying the Rentable Area shown on Exhibit H for
each portion of the Premises by the Base Rent per RSF shown on Exhibit H for
such space for the applicable period shown opposite the Base Rent per RSF shown
on Exhibit H.

     B.  "Tenant's Proportionate Share of Operating Expenses" and "Operating
Expense Deposits" (hereinafter defined);

     C.   "Rent Adjustment" equal to the amounts provided for in Exhibit J,
payable as set forth in Exhibit J.

     D.   An annual fee ("Special Tenant Fee") per square foot of Rentable Area
of the Premises for which it is applicable (as hereinafter set forth),
multiplied by the Rentable Area to which it applies, payable for each Fiscal
Year (hereinafter defined) set forth below, equal to the total of (i) Four
Percent (4%) of the Tax and Expense Component (hereinafter defined) for a Lease
Year immediately preceding the Fiscal Year for which it is payable,  plus (ii)
the Special Tenant Fee per square foot of Rentable Area of the Premises for
which it applies for the previous Fiscal Year.  The Special Tenant Fee shall be
payable in equal monthly installments in advance on the first day of each month
during each Fiscal Year as provided above.  The Special Tenant Fee is not a
component of Rent after the initial Term of the Lease (i.e. it is not a
component of Rent during the First Extension Period and Second Extension Period)
nor is it a component of Rent for Expansion or First Offer Space.

          (i)  Definitions.
               -----------

                    (a)   A "Fiscal Year" shall mean each twelve-month period
               commencing on an April 1.

                    (b)   "Tax and Expense Component" for any Lease Year means
               the lesser of the (1) Tax and Expense Cap (hereinafter defined)
               for such Lease Year and (2) the Tax and Expense Amount
               (hereinafter defined) for such Lease Year.

                    (c)   "Tax and Expense Amount" for a Lease Year means the
               amount per square feet of Rentable Area obtained by dividing

                           (1)  the sum of (i) Tenant's Proportionate Share of
                    Operating Expenses (excluding Taxes) for such Lease Year
                    plus

                                       7
<PAGE>

                    (ii) Tenant's Proportionate Share of Taxes payable
                    during such prior Lease Year (regardless of the Lease Year
                    to which attributable), by

                           (2)  Rentable Area of the Premises.

                    (d) The "Tax and Expense Cap" for any Lease Year shall be
               the product of 1.03 multiplied by the previous Tax and Expense
               Cap.  The first Tax and Expense Cap is 1.03 multiplied by the Tax
               and Expense Amount for Lease Year 2000.  Once the Tax and Expense
               Amount for Lease Year 2000 is determined, Landlord shall
               calculate the Tax and Expense Cap for the balance of the Term and
               Landlord and Tenant shall confirm it in a written and executed
               supplement to the Lease within 60 days after delivering of
               Landlord's statement under Section 4D.

        (ii)   When The Special Tenant Fee Commences.  With respect to the
               -------------------------------------
     23/rd/ floor space and Put Space, the Special Tenant Fee will be payable
     for each Fiscal Year commencing with the Fiscal Year beginning April 1,
     2002 . For the Extension Premises, the Special Tenant Fee will be payable
     for each Fiscal Year commencing April 1, 2005, and shall be at the same
     rate per square foot as the 23/rd/ floor and Put Space.

        (iii)  Example.  An example of calculation of the Special Tenant Fee
               -------
     is shown on Exhibit K.

        (iv)   Proration.  If space for which the Special Tenant Fee is payable
               ---------
     is added or deleted from the Premises in any Fiscal Year, then the Special
     Tenant  Fee shall be prorated for such Fiscal Year based on the RSF to
     which it applies for the period such RSF applies.

     E.  All other payments required to be made by the Tenant under this Lease.

     In the event the Term of this Lease commences on a day other than the first
day of a calendar month or in the event that this Lease ends prior to the end of
a twelve month period or ends on a day other than the last day of a calendar
month, the Rent for such month or such period shall be prorated (except as
provided in Section 4E or Exhibit J).  Tenant's obligation and covenant to pay
Rent is independent of every other covenant set forth in this Lease and shall
survive the expiration or termination of this Lease.

     F.  Interest at the Default Rate from the due date of each payment of Rent
due under this Lease until paid, if Tenant is ever in Default. The phrase
"Default Rate" means the lower of: (i) the highest lawful rate, or (ii) a rate
of interest equal to the sum of two percent (2%) plus the "Prime Rate". The
phrase "Prime Rate" means that rate of interest as defined in the most recently
published in the Wall Street Journal (or any successor publication) as the"Prime
                 -------------------
Rate",changing simultaneously and automatically with each published change in
the Prime Rate,such change to be effective as of and on the date published as
the effective date for the change in its said Prime Rate. In the event the Wall
                                                                           ----

                                       8
<PAGE>

Street Journal (or any successor publication) shall discontinue to publish a
--------------
Prime Rate, Landlord shall substitute therefor, in Landlord's judgment
reasonably exercised, the prime rate or base rate or similar rate of interest
announced or published by a major United States bank or major business
publication or financial publication.

4.   OPERATING EXPENSES  .

     A.   Definitions.  For the purposes of this Lease, the following terms,
words or phrases shall have the meanings and definitions described in this
subsection 4 A:

        (i)   "Lease Year" means a consecutive twelve month period commencing
              January 1 and ending December 31, both inclusive. In the event the
              term of this Lease ends on a date other than December 31, then in
              such event, "Lease Year" also means that period ending on the date
              of expiration of the term of this Lease and commencing on the
              immediately preceding January 1.

        (ii)  "Tenant's Proportionate Share" means 305,162/918,555, or thirty
               three and 22/100 percent (33.22%). If at any time additional
               space is added to the Premises, then Tenant's Proportionate Share
               shall increase by the percentage obtained by dividing the number
               of square feet of Rentable Area added, by 918,555. If at any time
               space is deleted from the Premises, then Tenant's Proportionate
               Share shall decrease by the percentage obtained by dividing the
               number of square feet of Rentable Area deleted, by 918,555. If at
               any time in the future the number of rentable square feet of
               office space in the Building is reduced by reason of a change in
               the Building's structure or by reason of the separation of
               ownership of a portion of the Building by a device such as
               vertical subdivision or submission of the Building to a
               condominium form of ownership, with the result that Tenant's
               Proportionate Share no longer reflects the ratio which the area
               of the Premises holds to the total amount of office space in the
               Building for which Landlord continues to pay Taxes and other
               Operating Expenses, then Landlord shall be entitled to equitably
               adjust Tenant's Proportionate Share to reflect such change in
               circumstance; provided that Operating Expenses associated with
               excluded rentable area are also equitably excluded.

        (iii)  "Operating Expenses" means Taxes (as hereinafter defined) and all
               costs, expenses and disbursements of every kind, nature or
               description, paid or incurred by or on behalf of the Landlord or
               its beneficiaries relating to the ownership, management,
               operation, maintenance and repair of the Property and the
               sidewalks and areas adjacent thereto and of the personal
               property, fixtures, machinery, equipment, systems and apparatus
               located therein or used in connection therewith, including, but
               not limited to: the costs of electricity, steam, water, fuel,
               heating, lighting, air conditioning, window cleaning,

                                       9
<PAGE>

               janitorial services; insurance (including, but not limited to,
               fire, extended coverage, liability, workmen's compensation,
               elevator, boiler, plate glass or any other insurance carried in
               good faith by the Landlord and applicable to the Property or the
               said personal property); painting; uniforms; management fees,
               (however if no managing agent is employed by Landlord, a sum in
               lieu thereof which is not in excess of the then prevailing rates
               for the management of first-class office buildings in Chicago,
               Illinois), supplies, sundries, sale or use taxes on supplies or
               services; costs of wages, salaries and bonuses of all persons at
               and below the level of Building manager engaged in the operation,
               maintenance and repair of the Property and so-called "fringe
               benefits" (including, but not limited to, overtime pay, social
               security taxes, unemployment insurance taxes, costs for providing
               coverage for disability benefits, costs for any pensions,
               hospitalization, welfare or retirement plans, vacation or
               severance pay, or any other similar or like expense incurred
               under the provisions of any collective bargaining agreement, or
               any costs or expenses which the Landlord, or its beneficiaries,
               pays or incurs to provide benefits for employees so engaged, or
               previously engaged, in the operation, maintenance and repair of
               the Property), the purchase price or rental cost, as applicable,
               of all building and cleaning supplies, tools, materials,
               machinery and equipment; depreciation of movable equipment used
               in the operation, maintenance, and repair of the Building,
               expenses imposed on Landlord pursuant to Laws, metal, elevator
               cab, lobby, plaza, sidewalk, curb and other public area
               maintenance and cleaning; interior and exterior landscaping and
               decoration; cleaning of grounds, sidewalks, parking lots, and
               other areas of the Property; a computer and other services for
               bookkeeping, record keeping, accounting and rent collection;
               association fees or dues; guards, watchmen and other security
               personnel, services and/or systems; Building telephone system;
               repairs, replacements and improvements which are necessary or
               appropriate for the continued operation of the Building as a
               first-class building (including those relating to the heating,
               air conditioning, mechanical and electrical systems, and
               elevators); blacktopping or other paving or repaving of parking
               areas; and painting or striping of such areas; snow removal from
               sidewalks and parking areas and from roofs and other areas of the
               Property; water and sewer rents, rates and charges, and all costs
               and charges (if any) for installing, repairing, or replacing
               water meters; excises, levies, licenses and permit fees; service
               charges, if any, with respect to police and fire protection,
               security, or street maintenance and lighting; fees and charges
               for construction, maintenance, occupancy or use of any vault,
               passageway or space in, on, over or under the street or sidewalks
               adjacent to the Building, or for the construction, maintenance or
               use of any part of the Building within the limits of any street;
               the charges of any independent contractor who, under a contract
               with the Landlord, or its representatives, does any of the work
               of operating, maintaining or repairing of the Property; legal and
               accounting fees and

                                       10
<PAGE>

             expenses; or any other expense or charge, similar or dissimilar,
             whether or not heretofore mentioned, which, in accordance with
             generally accepted management and accounting principles, would be
             considered as an expense of maintaining, operating or repairing the
             Property or the said personal property.

Operating Expenses shall not include, however, the following:

         (a) Costs of alterations of any tenant's premises;

         (b) Interest, principal, points and fees on debts or amortization on
any mortgage or debt instrument encumbering the Property (except as permitted in
(c) below above), as well as or lease rentals paid or payable on any ground or
underlying lease;

         (c) Costs of capital improvements, except that Operating Expenses shall
include (1) the cost of any capital improvements completed after the
Commencement Date of the Existing Lease (other than in connection with the
original construction of  the Building) which are initially projected by
Landlord to reduce Operating Expenses, provided that the cost of capital
improvement in (1) does not exceed $150,000, or if such cost does exceed
$150,000, then (v) such cost must be evenly amortized by Landlord over the
useful life of the capital improvement, with interest on the unamortized amount
at the Prime Rate, (w) such amortized costs (including interest as aforesaid)
shall only be included in Operating Expenses under this Lease for that portion
of the useful life of the capital improvement which falls within the Term, (x)
that portion of the annual amortized costs (including interest as aforesaid) to
be included in Operating Expenses shall be the lesser of such annual costs or
the projected annual reduction in Operating Expenses for the portion of the
useful life of the capital improvement which falls within the Term, as
reasonably estimated by Landlord in detail by expense category prior to making
such capital improvement, (y) all elements of such projection shall be completed
in accordance with generally accepted accounting principles and practices in
effect at the time the capital improvement is proposed to be made, and (z) a
copy of such projection and the underlying calculations shall be furnished to
Tenant prior to Landlord's including the cost of any such capital improvement in
Operating Expenses; and (2) provided that conditions (1)(v) and (1)(w) above are
satisfied, the cost of any capital improvements which are necessary to keep the
Land and Building  in compliance with all governmental rules and regulations
applicable from time to time thereto and enacted or adopted after the
Commencement Date of the Existing Lease.

         (d) All expenses for which Landlord has received any reimbursement to
the extent of such reimbursement, other than indirect reimbursement by the
payment by any tenant of base rent or its share of Operating Expenses;

         (e) Attorney's fees, costs and disbursements and other expenses
incurred in connection with tenant leases, including, without limitation,
negotiations with prospective tenants or disputes with any tenant but excluding
any expenses incurred in the performance of any of Landlord's obligations under
such tenant leases which are reimbursed by tenants payment of Operating
Expenses;

                                       11
<PAGE>

         (f) Expenses for repairs or other work occasioned by a casualty,
except that Operating Expenses shall include the cost of repairs or other work
occasioned by a casualty to the extent that such cost is not covered by
Landlord's insurance described in Section 25 hereof because of the deductible
amount permitted in Section 25;

         (g) Depreciation and amortization, except as provided herein and
except on materials, tools, supplies and vendor-type equipment purchased by
Landlord to enable Landlord to supply services Landlord might otherwise contract
for with a third party where such depreciation and amortization would otherwise
have been included in the charge for such third party's services, all as
determined in accordance with generally accepted accounting principles,
consistently applied, and when depreciation or amortization is permitted or
required, the item shall be amortized over its reasonably anticipated useful
life.

         (h) Real estate brokers' commissions or compensation and other
expenses (including, without limitation, architectural, space planning or
engineering services) incurred in leasing or procuring tenants;

         (i) The cost of any electric current furnished for lighting and
equipment (other than for the operation of fan rooms, telephone closets and
other elements of the Building's shared systems) located in the Premises or in
premises occupied by any other tenant in the Building;

         (j) The cost of correcting defects in the construction of the Building
or in the Building equipment provided that this shall not exclude from Operating
Expenses the cost of normal repair, maintenance and replacement expected with
the construction materials and equipment installed in the Building in light of
their specifications;

         (k) The cost of any repair made by Landlord pursuant to or as a result
of condemnation;

         (l) The cost of installing, operating and maintaining any specialty
facility, such as an observatory, broadcasting facilities, luncheon club,
athletic or recreational club, cafeteria or dining facility not available to
Tenant;

         (m) The cost of any repairs, alterations, additions, charges,
replacements and other items not specifically referred to in subparagraph (c) of
this Paragraph 5A and which, under generally accepted accounting principles, are
properly classified as capital expenditures;

         (n) Any management or other fees and expenses paid to an agent which is
related to Landlord or its beneficiary to the extent such fees are in excess of
the customary amounts which would be paid in the absence of such relationship;

         (o) Executive salaries and benefits above the grade of Building
manager;

                                       12
<PAGE>

         (p) Expenses incurred in connection with services or other benefits of
a type which are not provided to Tenant but which are provided to another tenant
or occupant of the Building;

         (q) Any penalty charges incurred by Landlord due to the violation of
any law;

         (r) Any compensation paid to clerks, attendants or other persons in
commercial concessions operated by Landlord;

         (s) Advertising and promotional expenditures;

         (t) costs for sculptures, paintings and other objects of art located
within the Building, except only for the costs of maintaining such objects in
the public areas of the Building;

         (u) Expenses incurred by Landlord, if any, in connection with the
operation, cleaning, repair, safety, management, security, maintenance or other
services of any kind provided to the mezzanine, first floor and basement or any
other portions of the Building which are leased for retail purposes which are
provided solely for the benefit of tenants occupying such portions or for the
parking garage; and

         (v) Expenses which could have been avoided by taking advantage of
available discounts offered by suppliers to the Building of services and
supplies and others in consideration for timely payments, unless Landlord
promptly and in good faith disputes such expenses.

         (w) Costs (including in connection therewith all attorneys' fees and
costs of settlement, judgments and payments in lieu thereof) arising from
claims, disputes or potential or actual claims, litigation or arbitration
pertaining to the Landlord or the Real Estate arising out of Landlord's tort,
unexcused breach of contract or violation of Laws.

         (x) Costs associated with the operation of the business of the entity
which constitutes Landlord as the same are distinguished from the costs of
operation of the Building including accounting and legal matters of such entity,
costs of defending any lawsuits with any mortgagee (except as the actions of
Tenant may be in issue), costs of selling, syndicating, financing, mortgaging or
hypothecating any of Landlord's interest in the Building, costs of any disputes
between Landlord and its employees (if any) not engaged in Building operation,
and disputes of Landlord with Building management.

         (y) Any expenses incurred by Landlord for use of any portions of the
Building to accommodate events not benefitting Tenant including, but not limited
to shows, promotions, kiosks, displays, filming, photography, private events or
parties, ceremonies and advertising beyond the normal expenses otherwise
attributable to providing Building services, such as lighting and HVAC to such
public portions of the building in normal operations during standard Building
hours of operation.

                                       13
<PAGE>

     If the Property is not fully occupied during all or any portion of the
Calculation Year (as defined below), Landlord may elect to make an appropriate
adjustment of the Operating Expenses for such year, employing sound management
principles, to determine the amount of "Operating Expenses" that would have been
paid or incurred by the Landlord had the Property been fully occupied and the
amount so determined shall be deemed to have been the amount of Operating
Expenses for such Calculation Year.  Further, if Landlord is not furnishing any
particular work or service (the cost of which if performed by Landlord would
constitute an Operating Expense) to a tenant who has undertaken to perform such
work or service in lieu of the performance thereof by Landlord, Operating
Expenses shall be determined to be increased by an amount equal to the
additional Operating Expense which reasonably would have been incurred during
such period by Landlord if it had at its own expense furnished such work or
service to such tenant; provided, however, that by reason of the foregoing
adjustment or increase Tenant shall in no event pay for any item of expense
which is adjusted or increased an amount in excess of the product of "Tenant's
Occupancy Share" (as hereinafter defined) multiplied by the total amount
actually paid or incurred by Landlord for such item.  For purposes hereof, the
term "Tenant's Occupancy Share" shall mean a fraction, the numerator of which is
the Rentable Area of the Premises, and the denominator of which is the total
occupied area of the office space leased and provided with services in the
Building. If any Operating Expenses, though paid in one year, relates to more
than one Lease Year, at the option of the Landlord, such Operating Expense may
be allocated among such related Lease Years in such a manner as Landlord may
reasonably determine.  If any Operating Expense benefitting the Property relates
to the Property and any other parcel of property, such Operating Expense shall
be allocated among all parcels of property to which it relates in such a manner
as Landlord may reasonably determine.

          (iv) "Taxes" means all federal, state and local governmental taxes,
               assessments and charges (including transit district taxes or
               assessments) of any kind or nature, whether general, special,
               ordinary or extraordinary, which Landlord or its beneficiaries
               shall pay or become obligated to pay because of or in connection
               with ownership, leasing, management, control or operation of the
               Property or of the personal property, fixtures, machinery,
               equipment, systems and apparatus located therein or used in
               connection therewith, including without limitation, any and all
               assessments made upon or with respect to any air rights or
               development rights now or hereafter appurtenant to or affecting
               the Property; all ad valorem taxes; any tax measured or based
               upon rental or rental receipts; any personal property taxes
               imposed upon the furniture, fixtures, machinery, equipment,
               apparatus, systems and appurtenances used in connection with the
               Property; fines, penalties, interest and similar charges, if any,
               applicable to the foregoing only if caused by Tenant's delayed
               payments of Tenant's Proportionate Share of Taxes or arising out
               of permitted installment payments (interest only but not fines or
               penalties); and all interest or costs attributable thereto.  The
               amount included in Taxes for any Lease Year shall be the amount
               indicated by the tax bills due or payable for that Lease Year
               (e.g., the taxes includable in Taxes for 2000 shall be the tax

                                       14
<PAGE>

               designated as 2000 taxes, whether or not they are paid in 2000),
               except that if the tax bills for such year are not available as
               of the date of the statement prepared for Landlord in accordance
               with subsection 4F, the amount of such taxes may be reasonably
               estimated by the person preparing the statement. There shall be
               deducted from Taxes, as determined for any year, the amount of
               any refund of taxes received by Landlord during such year.  There
               shall be included in Taxes for any year the amount of all fees,
               costs and expenses paid by Landlord during such year in seeking
               or obtaining any refund or reduction of Taxes.  Tenant shall be
               entitled to Tenant's Proportionate Share of any refund of Taxes
               attributable to any Lease Year during the Term for which Tenant
               paid Taxes based on Tenant's Proportionate Share in effect for
               such Lease Year.  If any special assessment payable in
               installments is levied against the Property, Taxes for any year
               shall include only installments of such assessments and any
               interest thereon, payable with respect to such year (all without
               regard to any right to pay or payment of any such special
               assessment in a lump sum or single payment).  Taxes shall not
               include any federal or state franchise, capital stock,
               inheritance, income from all sources generally, or estate taxes,
               except that if a change occurs in the method of taxation
               resulting in the substitution of any such taxes for any Taxes as
               herein above defined, such substituted taxes shall be included in
               Taxes.  Taxes include legal fees, court costs and expenses
               charged or payable by or on behalf of the Landlord for the
               contest of or protest of any Taxes.  Landlord shall consult with
               Tenant once the local assessing authorities of Cook County
               (Assessor and Board of Review) have issued the final assessed
               valuation for the Property and Landlord shall advise Tenant
               whether Landlord will be filing a specific objection suit in Cook
               County, Illinois, or appealing the assessed valuation with the
               Property Tax Appeal Board.  Landlord shall file such suit or
               appeal if it believes it would reasonably be successful in
               reducing the assessed valuation.  If Landlord decides not to file
               suit or appeal, Landlord shall inform Tenant of its reasons for
               such decisions.  Landlord may also file an objection to the tax
               rate in the appropriate forum.

          (v)  "Operating Expense Deposits" means one-twelfth (1/12th) of the
               amount of the Tenant's Proportionate Share of Operating Expenses
               (subject to the provisions of Section 4G below) for the then
               current Lease Year as Landlord shall reasonably estimate and
               communicate in writing to Tenant.

          (vi) "Calculation Year" means that Lease Year for which Tenant's
               Proportionate Share of Operating Expenses described in this
               Section 4 is payable, applicable or calculated.

                                       15
<PAGE>

     B.   Operating Expenses. Notwithstanding any provision of this Lease to the
contrary, it is mutually agreed that the Base Rent payable by the Tenant under
this Lease does not include Operating Expenses.

     C.   Operating Expense Deposits. Tenant agrees to pay to the Rental Agent
on the first day of each and every month during the term of this Lease the
Operating Expense Deposit (subject to the provisions of Section 4G below). The
Operating Expense Deposit shall be deposited against the Tenant's Proportionate
Share of the Operating Expenses due or to become due for the Lease Year during
which such deposits are required to be made.  All Operating Expense Deposits may
be commingled and need not be segregated by the Landlord or the Landlord's
Rental Agent, and may be held and utilized by the Landlord without payment to
the Tenant of interest or any sums for the use of any of said deposits. During
the last Lease Year or during any partial Lease Year during which this Lease
terminates, Landlord may include in the Operating Expense Deposit its estimates
of Tenant's Proportionate Share of the Operating Expenses which may not be
finally determined until after the expiration or termination of this Lease.

     D.   Landlord's Statement-Tenant's Payment Of Tenant's Proportionate Share
Of Operating Expenses.  No later than one hundred twenty (120) days after the
expiration of each Lease Year of this Lease, the Landlord shall cause to be
furnished to the Tenant a statement setting forth the following:

       (i)     Operating Expenses for the Calculation Year, divided into the
               following categories (to the extent applicable):  Utilities,
               Insurance, Repairs and Maintenance, Cleaning, Management Fee and
               Administration.  Landlord will also indicate the monthly Building
               occupancy for the Calculation Year shown as a percentage of total
               Rentable Area.  Landlord shall be permitted to change the
               categories above if Landlord changes its chart of accounts or
               method of accounting.

       (ii)    The amount of Tenant's Proportionate Share of Operating Expenses
               due Landlord for the Calculation Year, less credit for Operating
               Expense Deposits both paid by the Tenant in and allocable to said
               Calculation Year.

       (iii)   The Operating Expense Deposit due monthly, as aforesaid, during
               the Lease Year next following the Calculation Year for which the
               statement is given (subject to revision as aforesaid), including
               the amount or revised amount due and payable for the months prior
               to the rendition of the statement.

       The Landlord and Tenant do hereby acknowledge that the real estate tax
     bills for the Property, in relation to any Calculation Year, will not be
     available until near the end of the calendar year following such
     Calculation Year.  Accordingly, the Landlord shall have the right to amend
     such statement to take into account the actual real estate taxes payable in
     relation to a Calculation Year for a period of twelve months following the
     end of such Calculation

                                       16
<PAGE>

     Year. The Landlord shall furnish any such amended statement to Tenant as
     soon as reasonably feasible after Landlord receives the final installment
     bill for such real estate taxes relating to such Calculation Year.

          On the day for payment of Base Rent next following receipt of any such
     statement, and provided at least thirty days has elapsed after Tenant's
     receipt of such statement,  the Tenant shall pay to the Rental Agent the
     amount of Tenant's Proportionate Share of Operating Expenses due to the
     Landlord for the Calculation Year, as reflected in said statement, and the
     amount of Operating Expense Deposit due for the months between the
     expiration of the Calculation Year described in the statement to and
     including the month in which the statement is  furnished; provided,
     however, that such payment shall be made due and payable without prejudice
     to any written exception made by Tenant with respect to Landlord's
     statement in accordance with Section 4F.  If such statement shall reflect
     an amount due from the Landlord to the Tenant, then Landlord shall first
     apply such amount against the next due and payable Operating Expense
     Deposit and, if not exhausted, then to the next ensuing monthly Base Rent,
     due and payable and if there is any remaining balance, and Tenant is not in
     Default hereunder, said remaining balance shall be paid promptly to the
     Tenant.  No interest or penalties shall accrue on any amounts which
     Landlord is obligated to pay or credit to Tenant by reason of this
     subsection 4D.

     E.   Proration.  If the Lease Term ends on any day other than the last day
of December, any portion of  Tenant's Proportionate Share of Operating Expense
payment due Landlord shall be prorated, and the Tenant shall pay such amount
within ten (10) business days after  Tenant's receipt of the statement referred
to above.  Tenant's Proportionate Share of Operating Expenses shall not be
prorated for the Calculation Year in which the Commencement Date falls, it being
intended that such rent be paid as if the Commencement Date were January 1 of
such Calculation Year and amounts were payable and Operating Expense Deposits
made under this Lease and not the Existing Lease. In that regard, all payments
by Tenant on account of Tenant's Proportionate Share of Operating Expenses
(including payments under Section 4G under the Existing Lease) will be credited
as a payment by Tenant under this Lease.  If Tenant's Proportionate Share
changes during a Calculation Year, then Tenant's Proportionate Share of
Operating Expenses shall be prorated for such year based on the RSF for which
Tenant's Proportionate Share applied and the time period within the Calculation
Year to which it was applicable.

     F.   Books and Records.  Landlord shall maintain books and records in
accordance with sound accounting and management practices, reflecting the
Operating Expenses and Taxes. The Tenant or his representative shall have the
right to examine the Landlord's books and records relative to Operating Expenses
during normal business hours at any time within twenty (20) business days
following the furnishing by the Landlord to the Tenant of any statement
described in subsection 4F above. Unless the Tenant shall take written exception
to any item within forty (40) days after the furnishing of the said statement,
the said statement and all items and matters reflected therein shall be
considered as final and accepted by the Tenant.  If Tenant makes such timely
written exception, a certification as to the proper amount of Tenant's
Proportionate Share of Operating Expenses (as

                                       17
<PAGE>

defined in Section 4A(iii) of this Lease) shall be made by Landlord's
independent certified public accountant which shall be final and conclusive.
Tenant agrees to pay the cost of such certification unless it is determined
Landlord's original determination of Tenant's Proportionate Share of Operating
Expenses for the subject Calculation Year was in error by more than five percent
(5%) of actual Tenant's Proportionate Share of Operating Expenses, in which
case, such cost shall be paid by Landlord. If the dispute shall be determined in
Tenant's favor, Landlord, on demand, shall promptly pay Tenant the amount of
Tenant's overpayment of Tenant's Proportionate Share of Operating Expenses.

     G.   Payment of Taxes upon Receipt of Bill.  Notwithstanding the provisions
          -------------------------------------
of this Section 4 to the contrary, if Tenant is not in Default under this Lease,
the Operating Expense Deposit shall not include Tenant's Proportionate Share of
Taxes.  In such event, Landlord shall deliver to Tenant a copy of each bill for
Taxes after it is received by Landlord, together with a calculation of Tenant's
Proportionate Share of such Taxes.  Tenant shall deliver a check drawn on an
account of Tenant and payable to the appropriate taxing authority in an amount
equal to Tenant's Proportionate Share of such Taxes to Landlord within ten (10)
days of Tenant's receipt of a copy of such bill and the calculation of Tenant's
Proportionate Share as stated aforesaid, but Tenant shall deliver such check  to
Landlord  not  later than thirty (30) days  before  the due date for payment of
such Taxes. Upon expiration of the Term or if Tenant vacates the Premises prior
to Lease expiration, Landlord may require Tenant to pay an estimate of, or give
Landlord reasonable security for payment of, Tenant's Proportionate Share of
Taxes attributable to periods of Tenant's prior occupancy for which bills for
Taxes have not yet been received from governmental authorities.  Tenant's right
to pay Tenant's Proportionate Share of Taxes when bills for Taxes are received
from governmental authorities is personal to the original named Tenant and any
Affiliate (as defined in Section 16) to whom this Lease is assigned but shall
not extend to other sublessees or assignees.  Landlord's statement described in
Section 4D shall not be required to include Taxes except in instances where a
readjustment is required because Tenant has underpaid or overpaid Taxes pursuant
to this Section 4G.

5.   HOLDING OVER.  Tenant shall pay to the Landlord for each day Tenant retains
possession of the Premises or any part thereof after termination hereof, by
lapse of time or otherwise, (A) 150% of the amount of the daily rate of Base
Rent, Rent Adjustment and Special Tenant Fee (if applicable), plus (B) Tenant's
Proportionate Share of Operating Expenses then required by the terms hereof for
the last monthly period prior to the date of such termination and also pay all
Direct damages sustained by Landlord by reason of such retention. If Tenant
retains possession of the Premises for more than 60 days after termination of
the Lease, then Landlord shall be entitled additionally to consequential
damages. Acceptance by Landlord of Rent after such termination shall not
constitute or be deemed a renewal of this Lease and in no event shall it
constitute a waiver of or prejudice Landlord's right of reentry or any other
right.

6.   USE.  Tenant shall occupy and use the Premises only for general office
purposes and other purposes incidental to or reasonably related to Tenant's
business as it is conducted from time to time, and for no other use or purpose.
If any governmental license or permit shall be required for the

                                       18
<PAGE>

proper and lawful conduct of Tenant's business in or occupancy of the Premises
and if failure to secure such license or permit would in any way affect
adversely Landlord or the Building, then the Tenant, at its expense, shall
procure and thereafter maintain such licenses or permits and submit the same to
Landlord for inspection. Tenant shall comply with the terms and conditions of
each such license and/or permit. Tenant may, if Tenant so elects, install and
operate vending machines for the exclusive use of Tenant's employees and
invitees to dispense hot and cold beverages, ice cream, candy, food and
cigarettes, provided that such machines shall be maintained in a neat and
sanitary condition and shall comply with all applicable laws and ordinances.
Tenant may, if it so elects, install, equip and operate one or more cafeterias
or dining rooms, subject to the provisions of Section 55. In addition, Tenant
may serve alcoholic beverages therein for the exclusive use of Tenant's
employees and invitees, subject to compliance with all applicable codes and
ordinances provided further, Tenant has delivered to Landlord certificates
evidencing insurance (which insurance shall in all respects and at all times
comply with the provisions of Section 25 of this Lease) against any liability of
Landlord arising from serving of alcoholic beverages in the Premises.

7.   LANDLORD'S SERVICES AND OBLIGATIONS.  So long as Tenant is not in Default
hereunder, Landlord shall furnish the following services:

     A.   Heating-Air Conditioning.  Landlord shall furnish heat and air
conditioning to provide a temperature and humidity condition required, for
comfortable occupancy of the Premises under normal business operations, daily
from 8:00 a.m. to 6:00 p.m. (Saturday to 1:00 p.m.), Sundays and holidays
excepted. Tenant will be charged for all heating and cooling requested and
furnished before or after these hours at rates to be established and published
by Landlord.  Building standard air conditioning system is based on an average
electrical load of four watts/square foot and one person/100 square feet of
usable area.  The HVAC system will be capable of providing inside space
conditions of 74+/-2 degrees F. dry bulb at 50+/-5% relative humidity when
outside conditions are 91 degrees F. dry bulb and 74 degrees wet bulb.  The
heating installation will provide interior conditions of 72+/-2 degrees F.
inside when the outside temperature is -10 degrees F.  HVAC zones are on a
variable volume system with stripline diffusers (subject to adjustment pursuant
to voluntary or mandatory laws or regulations of public authorities.)  The HVAC
System is also designed to include the following:

     The discharge air temperature shall be 55 degrees F. to the mixing box.
     Fresh air is 20% per Chicago ventilation code.
     Air quantity is 0.07 CFM  to 1.2 CFM average.
     Air supply shall be filtered with a minimum efficiency of 65% per ASHRE
     standard 52-76.
     The HVAC controls in the Premises are pneumatic and have the capacity
     allowing Tenant control within the Premises to be maintained at the
     operating dry bulb temperature of +/- 2 degrees F.  Interior zones shall be
     manually adjusted by the Building personnel.

Wherever heat generating machines or equipment are used in the Premises which
affect the temperature otherwise maintained by the air conditioning system,
Landlord reserves the right to require Tenant to provide, install, operate and
maintain supplementary air conditioning units in the

                                       19
<PAGE>

Premises and the cost of providing, installing, operating and maintaining the
same shall be paid by Tenant.

     B.   Water.  Landlord shall furnish cold water from City of Chicago mains
from regular Building outlets for drinking, lavatory, toilet and vending machine
purposes drawn through fixtures installed by Landlord, or by Tenant with
Landlord's prior written consent, and hot water for public lavatory and vending
machine purposes from the regular supply of the Building.  Tenant shall pay
Rental Agent at rates fixed by Landlord for water furnished for any other
purpose as additional Rent hereunder upon being invoiced for the same.  The
water pressure and the hot water temperature must be not less than customarily
provided in premises comparable to the Premises in first-class office buildings
in the Chicago central business district.  At Landlord's election, Tenant shall
install and maintain, at Tenant's expense, a water meter to register consumption
of water for any other purposes. Tenant shall not waste or permit the waste of
water by Tenant or its employees.

     C.   Window Washing.  Landlord shall furnish window washing of all exterior
windows, weather permitting, at intervals to be determined by the Landlord, but
not less than three times per calendar year.  Tenant will not clean or cause to
be cleaned windows in the Premises from the outside in violation of applicable
Laws.

     D.   Janitor Service.  Landlord shall furnish daily janitor services in the
Premises, Saturdays, Sundays and holidays excepted in accordance with the
standards set forth in Exhibit D. For this purpose, Tenant shall permit
Landlord's Employees or janitorial contractor access to the Premises between
5:00 p.m. and 8:00 a.m., and permit such persons to use necessary electricity,
light and water without charge.  Tenant shall not provide janitor services
without the prior written consent of Landlord and then only subject to the
supervision of the Landlord and at Tenant's sole responsibility, cost and
expense, by contractors or employees at all times satisfactory to Landlord.
Landlord shall not be required to furnish janitorial services to deal with
conditions generated by receptions, parties, renovations, redecorating,
remodeling or conditions not within the scope of ordinary office use, and shall
be reimbursed by Tenant upon demand in the event such services are provided.

     E.   Elevator Service.  Landlord shall furnish passenger elevator service
in common with Landlord and other tenants, daily.  Daily freight elevator
service shall be available in common with Landlord and other tenants of the
Building and any use of the freight elevator service by contractors, agents or
employees of Tenant shall be at Tenant's sole cost, responsibility and expense
and at all times satisfactory to Landlord.

     F.   Window Coverings.  Landlord shall furnish blinds for all exterior
windows of standard type and color for the Building, which Tenant agrees not to
remove or alter.  Tenant may install, at its expense, drapes, window or door
coverings (and, if installed, shall maintain them in an attractive and safe
condition); provided, however, that in the sole judgment of Landlord they are in
harmony with the exterior and interior appearance of the Building, create no
safety or fire hazard and do not interfere with the HVAC system of the Building.

                                       20
<PAGE>

     G.   Monitor Access.  Landlord shall have a program to monitor access to
the Building, which may consist of a combination of security equipment and entry
verification procedures, and which may include lobby personnel or a system of
registration for monitoring access to the Building, Initially the monitoring
program will include key cards (to be provided by Landlord) for passenger and
garage elevators, as well as points of entry (to be provided by Tenant) on
Tenant's floors. The program will provide for procedures for verification of day
and time of entry and exit by individuals during hours specified by Landlord.
Tenant's security personnel will cooperate with Landlord in coordinating
Tenant's security procedures with Building procedures.

     H.   Other Services.  Landlord shall furnish Tenant, upon Tenant's request,
such other services (a) for which the Building is suited, which Landlord is able
to perform and which are customarily furnished by landlords of other first-class
office buildings in the central business district of the City of Chicago and (b)
for which Tenant and other tenants will pay Landlord as Operating Expenses or
for which Tenant will pay Landlord separately.

     I.   Interruption of Services.  Landlord does not warrant that any service
or availability of any Building system will be free from interruptions (i)
caused by labor controversies, accidents, inability to obtain fuel, steam, water
or supplies, governmental regulations, or other causes beyond the reasonable
control of Landlord, or (ii) which Landlord may reasonably deem necessary in
connection with the maintenance, repair or improvement of the Building.  No such
interruption of service shall be deemed an eviction or disturbance of Tenant's
use and possession of the Premises or any part thereof, or render Landlord
liable to Tenant for damages, by abatement of rent or otherwise, (except as
hereinafter provided) or relieve Tenant from performance of Tenant's obligations
under this Lease.  Tenant hereby waives and releases all claims against Landlord
for damages for interruption or stoppage of service.

          (a) If the Landlord ceases to furnish any of the services referred to
     in this Section 7 as a result of a condition which affects only the
     Building (and does not affect office buildings in general in the central
     business district of the City of Chicago), but not a condition described in
     Section 17 and if (i) such cessation is within Landlord's reasonable
     control, (ii) such cessation does not arise as a result of a negligent act
     or omission of Tenant or any other third party, or if such cessation does
     arise as a result of an act or omission of any third party, such cessation
     is able to be cured by reasonable and prompt action on the part of the
     Landlord but has not been so cured, (iii) as a result of such cessation,
     the Premises, or any floor within the Premises, is rendered untenantable
     (meaning the inability to use any or all of the floor(s) within the
     Premises in the normal course of its business) and Tenant in fact so ceases
     to use such floor(s), and (iv) such cessation continues for a period of
     three (3) business days after notice from Tenant of such cessation of
     services, then, in addition to such other remedies as Tenant may have
     either at law or in equity, the Rent payable hereunder shall be equitably
     abated based upon the percentage of the space in the Premises so rendered
     untenantable and not being used by Tenant.  The foregoing abatement shall
     become effective as of the first business day following the day the
     affected floor(s) become(s) untenantable and Tenant ceases to use such
     floor(s).  If there is a cessation of services described in Section 7A, 7B
     or 7E for

                                       21
<PAGE>

     any reason outside of Landlord's reasonable control (other than as
     described in Section 17, which shall control), whether or not affecting
     other office buildings in the Chicago central business district, Tenant may
     abate rent on the circumstances set forth in this paragraph if such
     cessation continues for more than five (5) business days after notice from
     Tenant of such cessation of services.

          (b) If any period of untenantability due to failure to receive
     services identified in Sections 7A, 7B and 7E involving more than fifty
     percent (50%) of the area of the Premises continues for longer than one
     hundred eighty (180) consecutive days, then unless subject to the
     provisions of Section 17 (which shall control), Tenant may elect to
     terminate this Lease by written notice to Landlord within the thirty (30)
     day period following such one hundred eighty (180) consecutive day period;
     provided, however, if such stoppage of services requires work to be
     performed, acts to be done, or conditions to be removed which, by their
     nature, cannot reasonably be performed, done or removed, as the case may
     be, within such one hundred eighty (180) consecutive day period, then if
     Landlord shall have commenced curing or correcting the same within such
     period and shall have diligently prosecuted such correction or cure, such
     one hundred eighty (180) consecutive period shall be extended by such
     additional time period not to exceed an additional one hundred twenty (120)
     days, for a total of three hundred  (300) days in the aggregate.

8.   TENANT'S OBLIGATIONS.

     A.   Repairs.  Except for ordinary wear and tear and as otherwise provided
in this Lease, Tenant shall, at all times during the Term hereof, at its sole
expense, keep all Tenant's movable and removable fixtures located in or
appurtenant to the Premises in good order, repair and condition, and Tenant
shall promptly arrange with Landlord to have Landlord (or Landlord's agent) make
repairs of all other damages to the Premises and the replacement or repair of
all damaged or broken glass (including signs thereon), fixtures and
appurtenances (including hardware and heating, cooling, ventilating, electrical,
plumbing and other mechanical facilities in the Premises), with materials equal
in quality and class to the original materials damaged or broken, within any
reasonable period of time specified by Landlord.  Landlord may, but shall not be
required to do so, enter the Premises at all reasonable times to make any
repairs, alterations, improvements or additions, including, but not limited to,
ducts and all other facilities for heating and air conditioning service, as
Landlord shall desire or deem necessary for the safety, preservation or
improvement of the Building, or as Landlord may be required to do by any
Government Entity or Law.  The cost of all repairs made by Landlord to the
Property which are made necessary as a result of misuse or neglect by Tenant or
Tenant's employees, invitees or agents shall be paid as additional Rent by
Tenant to Landlord within 30 days after Tenant is billed for same.  The cost of
all other repairs and replacements (except those caused by Tenant's misuse or
negligence and those relating to Tenant's movable fixtures) shall be paid for by
the Landlord and deemed an item of Operating Expenses.  Tenant shall notify
Landlord, in writing, of any damage to the Premises promptly after learning of
the same.

     B.   [INTENTIONALLY DELETED].

                                       22
<PAGE>

     C.   Laws and Regulations.  Tenant shall, at Tenant's sole expense, comply
and cause its employees, agents, clients, customers, invitees, visitors and
guests to comply with the rules and regulations set forth in Exhibit C attached
hereto and with all other reasonable rules and regulations Landlord may adopt
from time to time for the protection and welfare of the Building, the Property
and its tenants and occupants, and with all Laws (including, but not limited to,
the Americans With Disabilities Act), and with all rules, orders, regulations or
requirements of any fire insurance underwriters for insurance for the Building,
and with the directions of any public officers authorized by law affecting the
Premises and the use and occupancy thereof.  Landlord shall not be liable to
Tenant for any violation by any other tenant or such tenant's Employees of (i)
such tenant's lease, or (ii) the rules and regulations of the Building; but
Landlord shall attempt in good faith to apply the rules and regulations without
discrimination against any tenant of the Building. The terms, covenants,
conditions, and provisions of this Lease shall govern in the event of any
conflict or inconsistency between the Lease and the rules and regulations.

     D.   Advertising.  Tenant shall not advertise the business, profession or
activities of Tenant in any manner which violates the letter or spirit of any
code of ethics adopted by any recognized association or organization pertaining
thereto or use the name of the Building for any purpose other than that of the
business address of tenant, or use any picture or likeness of the Building or
"181 WEST MADISON BUILDING" or any other name by which the Building may from
time to time be known, on any letterhead, envelope, circular, notice,
advertisement, container or wrapping material, without the prior written consent
of Landlord.

     E.   Articles Sold.  Tenant shall not exhibit, sell or offer for sale, rent
or exchange in the Premises or on the Property any article, thing or service
except those ordinarily embraced within the use of the Premises specified in
Section 6 without the prior written consent of Landlord.

     F.   Hazardous Materials.

          (i)  During the term of the Lease, Tenant shall fully comply with any
               Environmental Laws.

                    (a) "Environmental Law" shall mean any Federal, state or
               local law, statute, ordinance, code, rule, regulation, license,
               authorization, decision, order, injunction, which pertains to
               health, safety, any Hazardous Material, or the environment
               (including but not limited to ground or air or water or noise
               pollution or contamination, and underground or above-ground
               tanks) and shall include, without limitation: Occupational Safety
               and Health Act, 29 U.S.C. Sections 651, et seq.; the Toxic
                                                       -------
               Substances Control Act, 15 U.S.C. Sections 2601, et seq.; the
                                                                -------
               Resource Conservation and Recovery Act, 42 U.S.C. Section 6901,
               et seq.; the Clean Air Act, 42 U.S.C. Sections 7901, et seq.; the
               -------                                              -------
               Clean Water Act, 33 U.S.C. Sections 1251, et seq.; the
                                                         -------
               Comprehensive Environmental Response, Compensation and Liability
               Act of 1980 and the 1986 Superfund Amendments and Reauthorization
               Act, 42

                                       23
<PAGE>

               U.S.C. Sections 9601, et seq.; the National Environmental Policy
                                     -------
               Act, 42 U.S.C. Sections 4231, et seq.; the Refuse Act, 33 U.S.C.
                                             -------
               Sections 407, et seq.; the Safe Drinking Water Act, 42 U.S.C.
                             -------
               Sections 300(f), et seq.; the Emergency Planning and Community
                                -------
               Right-to-Know Act, 42 U.S.C. Sections 11001, et seq.; the
                                                            -------
               Illinois Environmental Protection Act, 415 ILCS 5/1 et seq.; the
                                                                   -------
               Gasoline Storage Act, 430 ILCS 15/0.01 et seq.; the Municipal
                                                      -------
               Code of the City of Chicago; and any other local, state or
               federal environmental statutes, and all rules, regulations,
               orders and decrees now or hereafter promulgated under any of the
               foregoing, as any of the foregoing now exist or may be changed or
               amended or come into effect in the future, as well as applicable
               Department of Transportation regulations.

                    (b) "Hazardous Material" shall mean any substance, whether
               solid, liquid or gaseous; which is listed, defined or regulated
               as a "hazardous substance," "hazardous waste" or "solid waste,"
               or otherwise classified as hazardous or toxic, in or pursuant to
               any Law; or which is or contains asbestos, radon, any
               polychlorinated biphenyl, urea formaldehyde foam insulation,
               explosive or radioactive material, or motor fuel or other
               petroleum hydrocarbons; or which causes or poses a threat to
               cause contamination or a nuisance on the Premises or any adjacent
               property or is a hazard to the environment or to the health or
               safety of persons.  Tenant shall notify Landlord immediately if
               Tenant receives any notice of non-compliance with any
               Environmental Laws or rules and regulations promulgated
               thereunder, including, but not limited to, those enumerated
               above.

         Tenant shall not cause or permit its business in the Premises to be
     used to generate, manufacture, refine, transport, treat, store, handle,
     dispose, transfer, produce or process Hazardous Materials, except in
     compliance with all applicable Laws. Tenant shall notify Landlord
     immediately if Tenant learns of any non-compliance or of any facts (such as
     the existence of any release or threat of release of Hazardous Materials
     at, on, from or beneath the surface of the Premises) which could rise to a
     claim of non-compliance with such Laws. Notwithstanding the foregoing,
     Tenant may keep reasonable amounts of cleaning and office equipment fluids
     in the Premises properly stored in appropriate containers.

         (ii)  During the term of the Lease, Tenant shall obtain, shall fully
               comply with, and shall maintain in full force and effect all
               governmental licenses, permits, registrations and approvals
               (federal, state, local, county and foreign) necessary to conduct
               its business in the Premises including, but not limited to, those
               required by the statutes enumerated above in Paragraph (i).
               During the term of the Lease, Tenant shall keep a copy of all
               such permits at the Premises and shall make the same available at
               all reasonable times for Landlord's inspection.

                                       24
<PAGE>

         Tenant warrants and represents that if during the term of the Lease
     any violations are recorded or any notices are received  with respect to
     any of such licenses, permits, registrations and approvals or if a
     proceeding is commenced or threatened to revoke or limit any of them,
     Tenant shall notify Landlord immediately.

         (iii) In addition to all other indemnities under the Lease, Tenant
               hereby assumes for itself and for its successors and assigns any
               and all environmental, health and safety liabilities or
               obligations not otherwise caused by Landlord relating to the
               Premises and or Tenant's use of Premises, including, but not
               limited to, any liabilities or obligations in breach of the
               obligations imposed by Paragraphs (i) and (ii) hereof  on Tenant
               and its successors and assigns. Tenant, for itself and its
               successors and assigns, shall indemnify, defend and hold
               Landlord, its successors, assigns, owners and affiliates harmless
               from and against any claims, demands, liabilities and damages
               (including, but not limited to, reasonable attorneys' fees and
               court costs) arising out of or in connection with any
               environmental contamination or pollution of the Premises, and the
               existence on, or removal from, the Premises of any Hazardous
               Material not otherwise caused by Landlord.  The obligations of
               this paragraph shall survive the expiration or termination of
               this Lease.

     G.  Various Prohibited Uses. Tenant shall not install or operate any
refrigerating, heating or air conditioning apparatus or carry on any
manufacturing, production or mechanical business, operation or activity without
the prior written consent of Landlord; use the Premises for housing, lodging or
sleeping purposes; permit preparation or warming of food in the Premises
(warming of coffee and individual lunches of employees and business invitees of
Tenant excepted and except as otherwise expressly provided in Section 6 of this
Lease), or permit food to be brought into the Premises for consumption therein
by persons other than Tenant, its employees and business invitees, without the
prior written consent of Landlord. Landlord may in its sole discretion refuse
such permission or impose any conditions in granting it, and revoke it at will.
Tenant shall not occupy or use the Premises or permit the Premises to be
occupied or used for any purpose, act or thing which is in violation of any Law,
ordinance or governmental regulation, or which may be dangerous to persons or
property. Tenant, at its sole expense, shall comply with all rules, regulations
and requirements of the Illinois Inspection and Rating Bureau. Tenant shall not
do or permit anything to be done upon the Premises, or bring or keep anything
thereon which is in violation of rules, regulations or requirements of the
Chicago Fire Department, Illinois Inspection and Rating Bureau, Fire Insurance
Rating Organization, or any other similar authority having jurisdiction over the
Building. Tenant shall not use the Premises for any immoral purposes. Tenant
shall not at any time do or permit the manufacture, sale, purchase, use or gift
of any spirituous, fermented, intoxicating or alcoholic liquors. Nothing in this
subsection shall be read as limiting the restrictions on use imposed elsewhere
in this Lease.

     H.  Nuisances.  Tenant shall not bring or permit to be in the Building any
bicycle or other vehicle, or dog (except in the company of a blind person) or
other animal; make or permit any noise,

                                       25
<PAGE>

vibration or odor to emanate from the Premises; do anything therein tending to
create, or maintain, a public or private nuisance; disturb, solicit or canvass
any occupant of the Building, or do any act tending, in Landlord's judgment, to
injure the reputation, appearance or character of the Building as a first-class
building, or impair any building services or repairs, or the use of other areas
of the Building by Landlord or other tenants or occupants of the Building.

     I.  Overload Any Floor.  Tenant shall not overload any floors.

     J.  Alterations.  Tenant shall not make installations, alterations or
additions ("Alterations") in or to the Premises without submitting plans and
specifications ("Tenant's Plans") to Landlord and securing the prior written
consent of Landlord in each instance.  Landlord will not unreasonably withhold
condition or delay consent to any Alteration EXCEPT, HOWEVER, that Landlord may
withhold its consent in its sole and absolute discretion to any Alterations,
which will (a) alter or affect any portion of the Building's mechanical systems,
service systems, structural components, facade, roof, or foundation; (b) detract
from the use or character of the Building; (c) require amendment of any
certificate of occupancy for the Premises or the Building; (d) interfere with
the use or occupancy of Landlord or any other tenant in the Building; or (e)
require the consent of any insurer under any required insurance or any other
policy of insurance covering the Building. Landlord agrees to review and either
approve or disapprove (and noting with such disapproval the specific items not
approved) Tenant's Plans within ten (10) business days of Landlord's receipt of
a complete set of Tenant's Plans.  In the event Tenant's Plans are disapproved,
Tenant shall revise and resubmit Tenant's Plans expeditiously and Landlord shall
review the same and notify the Tenant of its approval or disapproval within five
(5) business days thereafter in the same manner as required for the initial
submittal.  Landlord's approval shall not be unreasonably withheld  conditioned
or delayed.  Landlord's authorized representative ("Landlord's Representative")
for the purpose of Tenant's deliveries or to communications to Landlord shall be
the Building General Manager, at the management office located in the Building.
Tenant shall not commence any work in the Premises until Tenant's Plans have
been approved.  Such Alterations shall be done at the sole cost and expense of
Tenant by contractors employed by Tenant, subject to Landlord's approval as to
the qualifications of such contractor (which shall not be unreasonably withheld
conditioned or delayed) and subject to all conditions Landlord may impose
including, conditions which will assure Landlord that all work will be performed
lien free, that adequate insurance coverage is provided, and that all
contractors (and all subcontractors) employed by Tenant shall agree to employ
only such labor as will not result in jurisdictional disputes or strikes or
cause disharmony with other workers employed at the Building. All Alterations
shall be constructed in a good and workmanlike manner and only new and good
grades of material shall be used, and shall comply with all insurance
requirements, and with all Laws. Tenant shall promptly pay Tenant's contractors
for such Alterations.  Tenant shall permit Landlord's Representative (and an
architect or engineer designated by Landlord) to observe all construction
operations within the Premises performed by Tenant's contractor, provided that
no supervision fee shall be charged by Landlord other than reimbursement of
Landlord's direct out-of-pocket costs. Such observation by persons on behalf of
Landlord shall be solely and only for the benefit of Landlord.  Tenant shall pay
to the Landlord the cost of any materials purchased from Landlord at Landlord's
actual invoice cost for said items or the cost of any labor of employees of
Landlord

                                       26
<PAGE>

performing work or providing service to Tenant, based on Landlord's customary
charges. Tenant shall not be charged for hoisting. No silence or statement by
any person acting on behalf of Landlord shall be deemed or construed as an
assumption by said persons or Landlord of any responsibility for or in relation
to the construction of the Premises or any guarantee that the work completed
within the Premises complies with Laws, complies with Tenant's Plans, or is
suitable or acceptable to the Tenant for Tenant's intended business purposes.
The cost of all work necessary to build out all of the Premises (including, but
not limited to, all labor, material, permits and working drawings and design
costs) shall, be the responsibility of Tenant, except for any required
contribution of Landlord expressly provided for in this Lease. Tenant shall
furnish to Landlord prior to commencement of Alterations, all building permits
(or other documentation required by the City of Chicago to commence work) and
other permits and certificates required by any Government Entity in connection
with the Alterations and all certificates of required insurance and bonds, and
within thirty (30) days of completion of any Alteration, any building or other
permits not previously furnished, "as built" plans and specifications, if any,
contractor's affidavits and full and final waivers of lien covering all labor
and material expended and used. If Tenant has applied for a building permit but
one has not been issued by the time work must commence solely due to delays in
the City of Chicago Building Department review process, Tenant shall provide
self-certification to Landlord as permitted under applicable City of Chicago
codes and ordinances and furnish Landlord a copy of the permit when received.
Tenant shall hold Indemnitee harmless from all claims, costs, damages, liens and
expenses which may arise out of or be connected in any way with said
installations, alterations or additions.

     If the estimated cost of any Alteration exceeds one hundred thousand
dollars ($100,000.00), before commencing any work with respect to such
Alteration, Tenant shall deliver to Landlord the following, at Tenant's sole
expense, each in form satisfactory to Landlord and each issued by an insurer
previously approved in writing by Landlord:  insurance policies for each
contractor for coverage and amounts reasonably satisfactory to Landlord which
policies shall name the parties set forth in Section 25C as additional insureds.
Tenant shall cause all work to be undertaken under the supervision of a licensed
architect or licensed professional engineer reasonably satisfactory to Landlord.

     K.  Consent Not Required For Decoration, etc.  The specific consent of
Landlord shall not be required for Non-Structural Work (hereinafter defined) and
Tenant may perform such work, so long as Tenant informs Landlord in reasonable
detail of the nature of the work, complies with Landlord's scheduling
requirements and otherwise complies with the provisions of this Section 8K.
"Non-Structural Work" means: painting, wall covering and carpeting not involving
hazardous or toxic materials; reconfigure moveable furniture, relocation of work
stations, install and rework telecommunications systems and install all new
computer, data processing or security equipment for Tenant and other work not
affecting the Building's structure or its mechanical, plumbing,
telecommunications, security and life safety, electrical or other building
systems (except for low wattage electrical work for which Landlord's consent is
not required and which does not require a building permit).  Non-Structural
Work, however, does not include any work which involves floor coring, access to
common electrical or telecommunications closets, penetrates the floor slab or
leaves the floor of the Premises on which the work is being performed or
requires entry into another tenant's

                                       27
<PAGE>

premises. Where plans and specifications are available for Non-Structural Work,
Tenant shall furnish Tenant's Plans to Landlord for its approval as provided
above.

     Landlord shall not be responsible for any labor or materials furnished to
Tenant.  No lien for any labor, materials, or other services, or things
furnished to Tenant shall attach to or affect Landlord's estate or interest in
the Premises, and/or the Property.  Tenant agrees to discharge, at Tenant's
expense (whether by payment, bonding, or otherwise) every lien filed against the
Premises and/or the Property for work claimed to have been done for or materials
claimed to have been furnished to Tenant, within thirty (30) days after written
notice from Landlord.

     L.  Records.  Tenant shall keep records of the cost of all Alterations
costing more than one hundred thousand dollars ($100,000) in each instance for
at least one year after substantial completion of the Alterations and shall give
copies of such records to Landlord upon request if Landlord requires the same in
connection with any Legal Proceeding or other reasonable purposes.

9.   RIGHTS RESERVED TO LANDLORD.  Landlord shall have the following rights
exercisable without notice and without liability to Tenant for damage or injury
to property, person or business (all claims for damage being hereby released),
and without effecting an eviction or disturbance or Tenant's use or possession
or giving rise to any claim for setoffs, or abatement of rent:

     A.  To change the name or street address of the Building, subject to the
provisions of Section 47.

     B.  To install and maintain signs on the exterior and interior of the
Building or anywhere on the Property, subject to the provisions of Section 47.

     C.  To designate all sources furnishing sign painting and lettering,
towels, or toilet supplies used or consumed on the Premises.

     D.  To have, and use, when appropriate and subject to the provisions of
Section 9F, passkeys or key cards to the Premises; provided that Landlord and
Tenant shall use reasonable efforts to protect any such magnetic key card system
or the individual cards against theft or misappropriation, and use reasonable
efforts to maintain the system; and provided further that such system will
permit the Landlord upon request of Tenant to cancel the effectiveness of the
card held by any partner or employee or invitee of Tenant upon such person's
departure from Tenant or for any other reason.  Landlord shall have the right to
retain keys and magnetic cards for entry into the Premises and all doors within
the Premises except for doors to such spaces as Tenant may designate as security
areas.  Tenant agrees to purchase only from Landlord additional duplicate keys
or magnetic cards as required, to change no locks or magnetic card readers, and
not to affix locks or magnetic card readers on doors without the prior written
consent of the Landlord not to be unreasonably withheld conditioned or delayed,
provided that Landlord shall respond to  Tenant's requests for such consent with
reasonable promptness.  Upon the expiration of the Term or Tenant's

                                       28
<PAGE>

right to possession, Tenant shall return all keys or magnetic cards to Landlord
and shall disclose to Landlord the combination of any safes, cabinets or vaults
left in the Premises;

     E.  To decorate, remodel, repair, alter or otherwise prepare the Premises
for reoccupancy during the last six months of the Term hereof, if during or
prior to such time Tenant vacates the Premises, or any time after Tenant
abandons the Premises.

     F.  To enter the Premises at reasonable hours to make inspections, or to
exhibit the Premises to prospective, purchasers, lenders or others, or for other
reasonable purposes.  To enter the Premises at reasonable hours to exhibit the
Premises to prospective tenants during the last eighteen months of the Term or
after Tenant has abandoned the Premises, or at any time with respect to the 36th
Floor.  With respect to Landlord's entry, reasonable advance notice (which may
be oral and may be given to Tenant's representatives) shall be required and
Landlord shall be accompanied by a representative of Tenant (unless otherwise
authorized) except in an emergency, except for a governmental inspection or to
provide janitorial or other routine services.  Landlord shall use reasonable
efforts to minimize interference caused by its entry.

     G.  To enter the Premises at any time in case of emergency (and by force,
if necessary in such event) in connection therewith.  If Tenant is not
personally present to open and permit entry into the Premises, Landlord or its
employees may forcibly enter the Premises without liability to Tenant or waiver
or modification of Tenant's obligations under this Lease.

     H.  To have access to all mail chutes according to the rules of the United
States Post Office.

     I.  To require all persons entering or leaving the Building during such
hours as Landlord may from time to time reasonably determine or during times of
emergency to identify themselves to a watchman by registration or otherwise and
to establish their right to leave or enter, and to exclude or expel any peddler,
solicitor or beggar at any time from the Premises or the Property.  Landlord
shall not be liable in damages for any error with respect to admission to or
eviction or exclusion from the Building of any Person.

     J.  To approve (in a reasonable manner) the weight, size and location of
safes, computers, all other heavy articles in and about the Premises and the
Building and to require all such items and other office furniture and equipment
to be moved in and out of the Property and Premises only at such time and in
such manner as Landlord shall direct and in all events at Tenant's sole risk and
responsibility.

     K.  At any time or times and without abatement of Rent or liability to
Tenant subject to conditions hereinafter set forth and the provisions of Section
9F, to decorate the Building or any part thereof, excluding the Premises, and to
make, at its own expense, repairs, alterations, additions and improvements,
structural or otherwise, in or to the Premises, the Property or part thereof,
and to perform any acts related to the safety, protection or preservation
thereof, and during such operations

                                       29
<PAGE>

to take into and through and store on the Premises or any part of the Property
all material and equipment required, and to erect scaffolding and to close or
temporarily suspend operation of entrances, doors, corridors, elevators or other
facilities, provided that Landlord shall (i) cause as little inconvenience or
annoyance to Tenant as is reasonably necessary in the circumstances, (ii) shall
not do any act which reduces the size of the Premises (except for duration of
the work), (iii) shall maintain reasonable accessibility to the Premises, and
(iv) shall use reasonable diligence in performing work. If any work to be
performed by Landlord (except in an emergency) requires modifications to the
Premises (other than temporary modifications needed to perform work), then
Landlord shall provide Tenant with copies of plans and specifications, if any,
which have been prepared for such work. If such work affects the appearance or
utility of the Premises in a material way, Tenant's shall have the right to
approve that aspect of the plans and specifications, which approval shall not be
unreasonably withheld. If Tenant desires to retain a consultant to assist in its
review of plans and specifications, it shall advise Landlord and Landlord agrees
to pay Tenant the reasonable fees of such consultant for such review. Tenant
shall permit Landlord to erect, use and maintain pipes, ducts and conduits in
and through the Premises, provided the same are installed adjacent to or
concealed behind walls and ceilings of the Premises. To the extent reasonably
practicable, Landlord shall install such pipes, ducts and conduits by methods
and in locations which will not materially interfere with or impair Tenant's
layout or use of the Premises. Landlord may do any such work during ordinary
business hours and Tenant shall pay Landlord for overtime and for any other
expenses incurred if such work is done during other hours at Tenant's request.

     L.  To do or permit to be done any work in or about the Premises or the
Property or any adjacent or nearby building, land, street or alley.  Without
limiting the foregoing, if excavation, foundation, other substructure work, or
other construction work shall be made or authorized upon land adjacent to the
Property, Tenant shall afford to the Person causing (or authorized to cause)
such excavation, license to enter the Premises to do such work as necessary to
preserve the walls of the Building from injury or damage, and to support the
same by proper foundations, without any claim for damages or indemnity against
Landlord, or diminution or abatement of Rent.

     M.  To grant to anyone the exclusive right to conduct any business or
render any service on the Property, provided such exclusive right shall not
operate to exclude Tenant from the use expressly permitted by Section 6 of this
Lease; and provided further that Tenant need not obtain its business or service
from such person or limit Tenants right to obtain such business or service from
another person.

     N.  To close the Building at 8:00 p.m. or at such other reasonable time as
Landlord may determine, subject, however, to Tenant's right to admittance under
such regulations as shall be prescribed from time to time by Landlord, it being
understood that Tenant's employees will require access to the Premises seven
days a week, twenty-four hours a day.

     O.  Except as provided in Section 6, to prohibit the placing of vending or
dispensing machines of any kind in or about the Premises without the prior
written permission of the Landlord.

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<PAGE>

     P.  All other rights reserved by the Landlord pursuant to the provisions of
this Lease.

10.  TELEPHONE, ELECTRIC AND OTHER SERVICES.

     A.  The electrical system of the Building was designed for Tenant's usage
(not including service described in Section 7A) on each floor to have a 400 amp
fused switch at 120/208 volts. Certain floors may have been modified to increase
that capacity.

     B.  Tenant shall make arrangements directly with the telephone and electric
companies servicing the Building for such telephone and electric service in the
Premises as may be desired by Tenant.  Tenant shall pay the entire cost of all
telephone charges, electricity consumed within the Premises, maintenance of
light fixtures and replacement of lamps, bulbs, tubes, ballasts and starters.
Tenant may, at its election, on ten (10) days' prior notice, provide for its own
lighting maintenance service.

     C.  If Tenant desires telegraphic, telephonic, burglar alarm, computer
installations or signal service (which service shall be at Tenant's sole
expense), Landlord shall, upon request, direct where and how all connections and
wiring for such service shall be introduced and run.  In the absence of such
directions, Tenant shall make no borings, cutting or install any wires or cables
in or about the Premises.

     D.  Tenant covenants and agrees that Landlord shall in no event be liable
or responsible to Tenant for any loss, damage or expense which Tenant may
sustain or incur if either the quality or character of electrical service is
changed or is no longer suitable for Tenant's requirements.  Tenant covenants
and agrees that at all times its use of electric current shall never exceed the
capacity of existing feeders and equipment in or otherwise servicing the
Premises when reviewed in conjunction with electrical usage of other tenants in
the Building or the Premises or wiring or installation; and also that it shall
make no alterations or additions to the electric equipment and/or appliances
without the prior written consent of Landlord in each instance.

11.  LANDLORD'S TITLE.  Landlord's title is and always shall be paramount to the
title of Tenant. Nothing herein contained shall empower Tenant to do any act
which can, shall or may encumber the title of Landlord.

12.  QUIET ENJOYMENT.  Subject to the Tenant's keeping and performing the terms,
covenants, conditions and provisions of this Lease, on its part to be performed,
Tenant shall and may peaceably and quietly have, hold and enjoy the Premises for
the Term of this Lease.

13.  LIMIT ON WAIVER OF CERTAIN CLAIMS. Subject to the provisions of Section
25A, to the extent permitted by law, no agreement of Tenant in this Lease shall
be deemed to exempt

                                       31
<PAGE>

Landlord from liability or damages for injury to persons or damages to property
caused by or resulting from the negligence of Landlord, its agents, servants or
employees, in the operation or maintenance of the Premises or Building.

14.  CONDITION OF PREMISES AND LANDLORD'S WORK.  To the extent available, the
Landlord will supply Tenant, at Tenant's request, drawings representing
additional premises to be leased by Tenant other than Existing Premises. Common
area exits, stairwells and men and woman restrooms in such additional premises
will have locking devises and door closures. Tenant, at its own cost, may
install combination locks on all restroom entrance doors where Tenant is a full-
floor tenant provided that there is a key override keyed to the Building current
key system. Landlord shall perform Landlord's Work as to such additional
premises to the extent not existing in the additional premises at the time
possession is delivered to Tenant. Tenant's taking possession of any additional
premises other than the Existing Premises shall be conclusive evidence that the
premises were then in good order, repair and satisfactory condition, except for
latent defects with respect to any of Landlords' Work. Except as may be set
forth in any written agreement between the parties, no promise has been made to
alter, remodel, improve, repair, decorate or clean any premises, and no
representation respecting the condition of the Premises or the Property has been
made to Tenant, except as made herein.

15.  TERMINATION.  At the termination of this Lease or Tenant's right to
possession hereunder, by lapse of time or otherwise:

     A.  Surrender of Keys.  Tenant shall surrender all keys of the Premises to
Landlord and make known to Landlord the explanation of all combination locks
remaining on the Premises.

     B.  Return of Premises.  Tenant shall return to Landlord the Premises and
all equipment and fixtures of Landlord broom-swept clean and in as good a
condition and state of repair as when Tenant originally took possession subject,
however, to (a) the provisions of Section 17 and Paragraphs C and D of this
Section 15; and (b) ordinary wear and tear, failing which Landlord may restore
the Premises, equipment and fixtures to such condition and state of repair and
Tenant shall, upon demand, pay to Landlord the reasonable cost thereof.

     C.  Removal of Additions.  All installations, additions, hardware, non-
trade fixtures and improvements temporary or permanent, except movable furniture
and equipment belonging to Tenant, in or upon the Premises, whether placed there
by Tenant or Landlord, shall be Landlord's property and shall remain upon the
Premises, all without compensation, allowance or credit to Tenant; provided,
however, that if Landlord so directs Tenant by notice as hereinafter provided,
Tenant shall promptly remove the items falling within categories described on
Exhibit I hereto, the pedestrian bridge described in Section 37, and any
personal property of Tenant placed in or upon the Premises by Tenant and
designated in the notice and repair any damage to the Premises or Building
caused by such removal.  If Tenant fails to do so, Landlord may remove the same
and Tenant shall, upon demand, pay to Landlord the reasonable cost of such
removal and of any necessary restoration of the Premises.  In no event shall
Landlord be responsible for the value, preservation or safekeeping of any

                                       32
<PAGE>

property so removed.  Approximately one year prior to the expiration of the
Lease, Landlord and Tenant shall conduct a walk- through of the Premises and
Landlord shall identify to Tenant which items Tenant is required to remove.
Landlord shall confirm the requirement of removal of such items in a notice to
Tenant.  With respect to any deletion of space from the Premises or any
termination due to casualty, eminent domain or Default of Tenant, Landlord shall
furnish such notice no later than thirty days after the contraction or
termination.

     D.  Floor Covering.  Tenant may remove any floor covering entirely paid for
and laid by Tenant, provided Tenant (a) removes all fastenings, paper, glue,
bases and other vestiges thereof and restores the floor surface to its previous
condition, or (b) pays to Landlord, upon demand, the reasonable cost of
restoring the floor surface condition, or Tenant may leave in place any floor
covering.

     E.  Property Presumed Abandoned.  All fixtures, installations, and personal
property belonging to Tenant not removed from the Premises upon termination of
this Lease and not required by Landlord to have been removed as provided in
Paragraph C of this Section 15, shall, at Landlord's election (which may be
exercised as to any or all of such items), be conclusively presumed to have been
abandoned by Tenant and title thereto shall pass to Landlord under this Lease as
by a Bill of Sale.

     F.  Survival.  The obligations of the Tenant contained in this Section 15
shall survive any termination of this Lease.

16.  ASSIGNMENT AND SUBLETTING.

     A.  Except as otherwise expressly provided herein, Tenant shall not,
without the prior written consent of Landlord in each instance or as otherwise
provided in this Section 16: (i) assign, transfer, mortgage, pledge, hypothecate
or encumber, or subject to or permit to exist upon or be subjected to any lien
or charge, this Lease or any interest under it; (ii) allow to exist or occur any
transfer of or lien upon this Lease or the Tenant's interest herein by operation
of law; (iii) sublet the Premises or any part thereof; or (iv) permit the use or
occupancy of the Premises or any part thereof by anyone other than the Tenant
and Tenant's employees.  In no event shall this Lease be assigned or assignable
by voluntary or involuntary bankruptcy proceedings or otherwise, and in no event
shall this Lease or any rights or privileges hereunder be an asset of Tenant
under any bankruptcy, insolvency or reorganization proceedings.

     For the purposes of this Section 16, if The Northern Trust Company is no
longer Tenant, then the transfer of the direct or indirect ownership or control
of more than fifty percent (50%) of any Person, however accomplished, whether
directly or indirectly, in a single transaction or in a series of related or
unrelated transactions, and not including transfers of stock of a company
publicly traded on a national securities exchange or quoted on the NASDAQ stock
market or other quotation system available for public trading of securities,
shall be deemed an assignment of this Lease.

                                       33
<PAGE>

     Consent by Landlord to any assignment or sublease shall not be deemed to
constitute consent to any further assignment or subleases by Tenant or any
assignees or subtenants.

     B.  Tenant covenants that, notwithstanding any assignment or transfer,
whether or not in violation of the provisions of this Lease, and notwithstanding
the acceptance of Rent by Landlord from an assignee or transferee or any other
Person, Tenant shall remain fully and primarily and with the assignee or
transferee jointly and severally liable for the payment of all Rent due and to
become due under this Lease and for the performance and observance of all of the
covenants, agreements, terms, provisions and conditions of this Lease on the
part of the Tenant to be performed or observed, except as otherwise provided
herein.  After any assignment, subletting, or other transfer permitted under
Subsection 16A or 16B, Tenant's liabilities and obligations under this Lease
shall not be discharged, released or impaired in any respect by an agreement or
stipulation made by Landlord (or the holder of any Superior Encumbrance)
extending the Term or modifying any obligations contained in this Lease, or by
any waiver or failure of Landlord to enforce any of Tenant's obligations under
this Lease.

     C.  Except as set forth in Section 16D, Landlord may withhold its approval
of Tenant's proposed sublease or assignment for the reason that the proposed
subtenant or assignee is an existing tenant in the Building if, at the time of
the proposed sublease or assignment, Landlord has existing available premises in
the Building that can accommodate the existing tenant's  space requirements;
provided, however, Landlord shall have 120 days from the date that the existing
tenant first contacted Landlord or the date that Tenant (or its agent) first
notified Landlord of its proposed sublease or assignment to the existing tenant
(whichever is earlier) within which to negotiate the basic terms of a lease at
the Building with the existing tenant.   If  Landlord and the existing tenant
cannot agree on the basic terms for any such lease within such 120 day period,
then Landlord may no longer withhold its approval of the sublease or assignment
for the reason that the proposed sublessee or assignee is an existing tenant.

     D.  Tenant may at any time and from time to time assign or transfer this
Lease or any interest under it, and may sublet the Premises or any part thereof
to (i) a Person controlling, controlled by or under common control with The
Northern Trust Company or to any successor to The Northern Trust Company by
merger, consolidation or acquisition (any such entity or successor being
sometimes hereafter referred to as an "Affiliate" of Tenant), without Landlord's
consent; or (ii) any financially responsible Person approved by Landlord, (which
approval shall not be unreasonably withheld, denied conditioned or delayed)
whose stated use of the Premises will not result in a breach of an exclusive use
provision for space in the Building theretofore granted by Landlord (subject to
Landlord's written right to recapture as hereafter set forth).  Not less than
thirty (30) days prior to the proposed commencement of such assignment or
sublease to a Person other than an Affiliate of Tenant, Tenant shall give
Landlord written notice of the proposed assignment or sublease which notice
shall contain the name of the proposed assignee or sublessee and proposed
principal terms thereof and shall be accompanied by the last available financial
statement of such proposed assignee or sublessee.  Within ten (10) days of
Landlord's receipt of such written notice and financial statement Landlord by
notice to Tenant  shall approve or disapprove of the

                                       34
<PAGE>

proposed assignee or sublessee, or if such proposed transfer is (i) a sublease
to other than an Affiliate (A) for more than 50% of the Rentable Area of the
Premises (when taken together with all other space subleased at that date or
proposed to be subleased at such time) as of that date, and (B) for
substantially all of the remainder of the Term, or (ii) an assignment to other
than an Affiliate, Landlord may terminate this Lease as to such proposed
subleased space in the case of a proposed sublease, or all of the Premises in
the case of a proposed assignment. If Landlord exercises such right to
terminate, Tenant shall have ten (10) days from receipt of Landlord's notice to
terminate to rescind its notice of sublease, assignment or transfer, by
notifying Landlord in writing of its rescission, in which case Landlord shall
not proceed with any such termination. If Landlord does not terminate as
aforesaid, Landlord may withhold its consent to such proposed assignee or
sublessee only for reasonable reasons related to the financial responsibility of
the proposed Person but such disapproval may not be given because (a) vacant
space exists in the Building, (b) such proposed assignee or sublessee is a
tenant in the Building or has discussed tenancy in the Building with the
Landlord, or (c) the price or rental rate of the proposed assignment or
sublease. Failure of Landlord to respond within such ten (10) day period shall
constitute Landlord's approval of such proposed assignee or sublessee. Upon the
assignment of all of Tenant's interest in this Lease to an assignee wherein the
Rent to be paid by the assignee equals, or exceeds the Rent payable under this
Lease, which assignment is approved by Landlord as aforesaid (including an
assignment to an Affiliate, if such an Affiliate is approved by Landlord,
although Tenant is not required to obtain approval of an assignment to an
Affiliate, but if Tenant elects not to, it shall not be relieved of its
obligations under this Lease]), and delivery of a written assumption of this
Lease and the obligations hereunder by such assignee, Tenant shall be relieved
of all obligations under this Lease accruing after such release, except the
obligation to pay to the Landlord excess rent as provided in the next paragraph.
If Tenant's notice shall entitle Landlord to terminate this Lease as to the
entire Premises and Landlord shall elect to terminate this Lease as to the
entire Premises, the Term of this Lease shall expire and end on the date stated
in Tenant's notice as fully and completely as if that date had been herein
definitely fixed for the expiration of the Term. If, however, this Lease be
terminated pursuant to the foregoing with respect to less than the entire
Premises, the Rent herein reserved shall be adjusted on the basis of the number
of square feet retained by Tenant in proportion to the number of square feet
contained in the Premises, as described in this Lease, Tenant shall pay for the
cost of physically separating the portion of space so deleted from the Premises,
and this Lease, as so amended, shall continue thereafter in full force and
effect. In such event, at Landlord's request, Tenant shall promptly execute and
deliver to Landlord an appropriate modification of this Lease in a form
satisfactory to Landlord and Tenant.

     E.  With respect to any sublease, Tenant shall bear all costs of providing
appropriate means of ingress and egress from the sublet space (or of separating
the space to be subleased from the remainder of the Premises).

     F.  If Tenant shall assign or transfer its interest in this Lease or sublet
the Premises pursuant to this Section 16, then Tenant shall pay to Landlord as
additional rent within 10 days after receipt under any such assignment or in the
case of a sublease on the first day of each month during the term of any such
sublease, one-half (1/2) of the excess of all rent over the sum of (x) all Rent
then

                                       35
<PAGE>

payable to Landlord under this Lease for said month (or if only a portion of the
Premises is being sublet, then portion of the Rent then payable to Landlord
under this Lease for said month which is allocable on a square foot basis to the
space sublet) plus y) an amount equal to the quotient of "Tenant's Costs" (as
hereinafter defined) incurred by Tenant in connection with said sublease divided
by the number of months in the term of such sublease. As used in the preceding
sentence, "Tenant's Costs" for such assignment or sublease shall include the
unamortized amount of improvements made at Tenant's expense, alterations to the
Premises in connection with such assignment or sublease made at Tenant's
expense, and leasing commissions, rent concessions, advertising cost, and legal
expenses in connection with such assignment or sublease.

     G.  Tenant agrees that if it requests Landlord's consent to an assignment
or a subletting, that it shall reimburse Landlord for its reasonable costs and
expenses in considering whether to grant its consent (including, but not limited
to, reasonable attorneys' fees).

17.  UNTENANTABILITY.

     A.   In the event (a) a substantial part of the Premises is damaged by fire
          or other casualty, or (b) a substantial part of the Building (or any
          area required to provide access or services to the Premises or
          Building) is damaged by fire or other casualty, Landlord shall, within
          60 days after the date of said fire or casualty, give Tenant an
          estimate of the length of time that will be required to complete the
          rebuilding and restoration of the Premises or the Building (including
          an estimated construction schedule) so that affected areas of the
          Premises or Building are no longer untenantable. For purposes of this
          Section 17, a "substantial part of the Premises" shall be deemed
          damaged if at least 100,000 square feet of Rentable Area of the
          Premises is thereby rendered untenantable, and a "substantial part of
          the Building (or any area required to provide access or services to
          the Premises of Building)" shall be deemed damaged if at least 300,000
          square feet of Rentable Area in the Building (whether within or
          outside the Premises) is rendered untenantable.  "Untenantable" shall
          mean that the normal conduct of a tenant's business in  its premises
          in the Building, is materially impaired. If such estimated time for
          rebuilding and restoration exceeds twelve (12) months from the date of
          such fire or other casualty, or if  the unexpired portion of the Term
          as of the date of such fire or other casualty is eighteen months (18)
          or less, then either Landlord or Tenant (but only if more than 100,000
          square feet of Rentable Area of the Premises is rendered untenantable)
          may terminate this Lease upon written notice to the other given any
          time within 30 days after Landlord gives Tenant written notice
          containing the estimate.  If neither party so elects, this Lease shall
          not terminate (except as otherwise provided in Section 17F) and
          Landlord shall, at Landlord's expense, use all reasonable efforts to
          repair and restore the Premises or Building within the estimated time
          for rebuilding and restoration given by Landlord to Tenant in its
          notice, subject to (i) delays due to insurance adjustment, or (ii)
          matters beyond Landlord's reasonable control, and Rent shall abate on
          a per diem basis during the period of reconstruction and repair until
          the Premises are again tenantable.

                                       36
<PAGE>

     B.   In the event that less than a substantial part of the Premises is
          damaged by fire or other casualty or less than a substantial part of
          the Building (or any area required to provide access or services to
          the Premises or Building) is damaged by fire or other casualty, then
          Landlord shall, except during the last eighteen (18) months of the
          term hereof, proceed with all due diligence to repair and restore the
          Premises, subject, however, to (i) reasonable delays for insurance
          adjustments, and (ii) delays caused by forces beyond Landlord's
          reasonable control; but Landlord shall not be liable to incur
          overtime, double time, or other premium charges in order to expedite
          the work of repair or restoration.  In such event, Rent shall abate in
          proportion to the untenantable area of the Premises during the period
          while repairs are in progress. If the Premises or Building are damaged
          by fire or other casualty as aforesaid during the eighteen (18) months
          year of the  Term hereof (unless Tenant has exercised an available
          option to extend), either Landlord or Tenant shall have the right to
          terminate this Lease as of the date of fire or other casualty by
          written notice to the other given any time written thirty (30) days
          after the date of such fire or other casualty.

     C.   In the event Landlord is obligated or elects pursuant hereto to
          restore and rebuild the Premises, or any portion thereof, or the
          Building as a result of a fire or other cause, Landlord shall only be
          obligated to restore or rebuild those portions of the improvements in
          the Premises, or the affected portion thereof constituting the core
          and shell of the Building and not improvements or betterments to the
          Premises, including Alterations.

     D.   Landlord shall have no liability for any loss, cost, expense, damage,
          or compensation whatsoever (including any claim for inconvenience,
          loss of business or annoyance) by reason of any restoration of the
          Premises or the Building under this Section.

     E.   In the event Landlord is obligated or elects pursuant hereto to
          restore and rebuild, then at Tenant's expense, Tenant shall repair and
          restore improvements and betterments to the Premises Alterations which
          are not required to be repaired or restored by Landlord following
          substantial completion of Landlord's repair and restoration work, if
          any (as determined by Landlord's architect).

     F.   If Landlord is unable to or fails to substantially complete its repair
          or restoration by the date ("Outside Date") which is the later of (i)
          the estimated completion date plus 60 days or (ii) twenty-four (24)
          months from the date of such fire or casualty, in each case as
          extended by (a) delays due to insurance adjustment or (b) matters
          beyond Landlord's reasonable control, then either Landlord (if it has
          used all reasonable efforts to perform its repair and restoration as
          required above) or Tenant may terminate this Lease by notice to the
          other given within thirty (30) days after such Outside Date.

                                       37
<PAGE>

     G.   In the case of termination of this Lease under this Section 17, Rent
          shall abate from the date of the fire or casualty in proportion to the
          area of the Premises rendered untenantable.

18.  DEFAULTS; CONDITIONS LIMITATIONS; REMEDIES.

     A.  Each of the following events shall be a "Default" under this Lease:

         (i)    Tenant fails to make any payment of Rent when due, and such
                failure continues for ten (10) days after written notice from
                Landlord.

         (ii)   Tenant fails to keep or perform any other term, covenant,
                condition, or provision of this Lease, and such failure
                continues for thirty (30) days after written notice from
                Landlord specifying such failure unless such failure requires
                work to be performed, acts to be done, or conditions to be
                removed which cannot be performed, done or removed within such
                thirty (30) days, in which case the Default shall not be deemed
                to exist so long as Tenant:

               (a)  advises Landlord by written notice within said ten (10) days
                    that Tenant intends to take all steps necessary to
                    diligently remedy such failure and specifies a date by which
                    all steps will have been completed (which shall not, exceed
                    thirty (30) days after the date of Landlord's notice subject
                    to matters beyond Tenant's reasonable control);

               (b)  duly commences curing the same within such period; and

               (c)  diligently and continuously prosecutes to completion all
                    steps necessary to remedy the same;

         (iii) Tenant, admits, in writing, that Tenant is unable to pay Tenant's
               debts as such become due;

         (iv) Tenant makes an assignment for the benefit of creditors;

         (v)  Tenant files a voluntary petition in bankruptcy or a petition is
              filed against Tenant and an order for relief is entered, or Tenant
              files any petition or answer seeking any reorganization,
              arrangement, composition, readjustment, liquidation, dissolution
              or similar relief under any present or future federal, state or
              other law, or Tenant seeks or consents to, acquiesces in, or
              suffers the appointment of any trustee, receiver, or liquidator of
              Tenant or of the Premises (or Tenant's interest therein) or of all
              or any substantial portion of Tenant's assets;

                                       38
<PAGE>

         (vi)    if, within sixty (60) days after the commencement of any
                 proceeding against Tenant seeking any reorganization,
                 arrangement, composition, readjustment, liquidation,
                 dissolution or similar relief under any present or future
                 federal, state or other law, such proceeding is not dismissed
                 or if, within sixty (60) days after the appointment (without
                 the consent or acquiescence of Tenant) of any trustee, receiver
                 or liquidator, of Tenant or of all or any substantial part of
                 Tenant's properties or of the Premises (or Tenant's interest
                 therein), such appointment is not vacated or stayed on appeal
                 or otherwise, or if, within thirty (30) days after the
                 expiration of any such stay, such appointment shall not have
                 been vacated;

         (vii)   Tenant sublets the Premises (or any part thereof) or mortgages,
                 pledges, assigns, transfers, or otherwise disposes of or
                 encumbers this Lease (or any part of Tenant's right, title and
                 interest hereunder) without complying with all requirements of
                 this Lease;

         (viii)  if the Premises shall be taken or occupied by any Person other
                 than Tenant except as expressly permitted under Section 16
                 hereof;

         (ix)    Tenant fails to cure, immediately after receipt of notice form
                 Landlord, any hazardous condition which Tenant has created in
                 violation of any Law or this Lease;

         (x)     if a levy under, execution or attachment is made against Tenant
                 or Tenant's property and is not vacated or removed by court
                 order, bonding or otherwise within thirty (30) days thereafter;

         (xi)    if the Premises become vacant, deserted or abandoned; and/or

         (xii)   if there shall be any default by Tenant under any other lease
                 or sublease of space in the Building which shall not be
                 remedied within the applicable grace or cure period, if any,
                 provided therein.

     B.  If and whenever any Default occurs, at Landlord's option, Landlord may,
but shall not be required to do so:

         (i)     give written notice to Tenant (the "Lease Termination Notice"),
                 stating that this Lease and the Term shall expire and terminate
                 on the date specified in such Lease Termination Notice; or

         (ii)    give written notice to Tenant (the "Possession Termination
                 Notice"), stating that Tenant's right to possession, but not
                 the Lease, shall expire and terminate on the date specified in
                 such Possession Termination Notice.

                                       39
<PAGE>

     Either the Lease Termination Notice or the Possession Termination Notice
may take the form of a statement contained in the notices (if any) required by
subsection 18 A advising the Tenant that unless the Tenant has cured the
violation stated in the notice within the applicable cure period (if any),
Landlord has elected to terminate the Lease or Tenant's right to possession, but
not the Lease, as the case may be, as of the expiration of such cure period.

     C.  In the event that Landlord gives the Lease Termination Notice, this
Lease and the Term (and Tenant's entire right, title and interest therein) shall
expire and terminate as if the date specified in the Lease Termination Notice
were the expiration date, and Tenant shall quit and surrender the Premises but
shall remain liable as hereinafter provided.  In the event that Landlord gives
the Possession Termination Notice, this Lease shall continue in effect; however,
Tenant's right to possess and occupy the Premises shall expire and terminate on
the date specified in the Possession Termination Notice, and Tenant shall quit
and surrender the Premises on or before such date but shall remain liable as
hereinafter provided.

     D.  If and whenever any Default occurs, or if this Lease and the Term
terminate under Subsection 18C or otherwise, or if Tenant's right of possession
terminates under Subsection 18C or otherwise, Tenant shall surrender possession
and vacate the Premises immediately, and deliver possession thereof to Landlord,
and hereby irrevocably grants to Landlord full and free license to enter into
and upon the Premises, with or without notice or process of law, and repossess
Landlord of the Premises and to expel or remove Tenant and any others who may be
occupying or within the Premises and to remove any and all property therefrom
using such force for that purpose as may be necessary without being liable to
indictment, prosecution or damages (or being deemed to be guilty of trespass,
eviction, forcible entry or detainer, or conversion of property, or otherwise);
and Tenant shall remain liable as hereinafter provided.  If, Landlord so re-
enters, at its option, Landlord may, at Tenant's sole expense payable on demand
as additional Rent:

         (i)   repair and alter the Premises in such manner as Landlord may deem
               reasonably necessary or desirable in connection with efforts to
               relet the Premises and change the locks to the Premises without
               relieving Tenant of any liability whatsoever under this Lease;
               and/or

         (ii)  let or relet the Premises (or any parts thereof) for the whole
               or any part of the remainder of the Term, or for a longer period,
               in Landlord's name or as agent of Tenant.

No re-entry by Landlord, whether under summary proceedings or otherwise, shall
absolve or discharge Tenant from any liability whatsoever under this Lease or be
deemed an election by Landlord to terminate or accept a surrender of this Lease.
Except that Landlord covenants to use reasonable efforts to mitigate damages,
Landlord have no obligation whatsoever to relet the Premises (or any parts
thereof), or to collect any rent or other sum due on any such reletting, or
accept any tenant offered by Tenant or to observe any instructions given by
Tenant concerning such reletting; and except to the extent required by law,
Landlord's failure to relet, to collect rent or to accept such

                                       40
<PAGE>

tenant or instructions shall not relieve Tenant of any liability whatsoever
under this Lease. Tenant shall not be entitled to, or receive any credit for,
any excess of rents collected upon any reletting of the Premises over the Rents
and other sums payable by Tenant under this Lease.

     E.  If this Lease and the Term terminate under Subsection 18C or otherwise,
or if Tenant's right of possession is terminated under Subsection 18C or
otherwise, or if Landlord re-enters the Premises under Subsection 18D or by any
summary proceeding or other Legal Proceeding, then, in any of such events,
Tenant shall pay Landlord on demand:

        (i)    all Rent then due under this Lease;

        (ii)   all reasonable costs and expenses (including reasonable
               attorneys' fees and disbursements) which Landlord pays or incurs
               in terminating this Lease or Tenant's right of possession, re-
               entering, retaking, repossessing, repairing and/or altering the
               Premises, and removing all Persons and property therefrom; and

        (iii)  all reasonable costs and expenses which Landlord incurs in
               securing any new tenant(s) of the Premises (including such costs
               as brokerage commissions, reasonable attorneys' fees and
               disbursements, and expenses of preparing the Premises for
               reletting, and if Landlord maintains the Premises, all costs and
               expenses of maintaining the Premises).

     F.  If Tenant's right of possession is terminated as aforesaid, Tenant
shall pay Landlord on demand, also, as damages, any deficiency (a "Deficiency")
between the Rent reserved in this Lease for the period which otherwise would
have constituted the unexpired portion of the Term and the amount, if any, of
rents collected under any reletting effected pursuant to subsection 18D(iii) for
any part of such period (after deducting from such collections all amounts
actually paid by Landlord under Subsection 18 E(iii)).  Tenant shall pay any
Deficiency in installments on the days specified in this Lease for payments of
Rent.  Landlord shall be entitled to recover from Tenant each Deficiency
installment as the same arises; and no Legal Proceeding to collect, any
Deficiency installment shall prejudice Landlord's right to collect any
subsequent installment by a similar or other Legal Proceeding.

     G.  If Landlord terminates this Lease as aforesaid, Tenant shall pay
Landlord, on demand, in lieu of any further Deficiency, as and for liquidated
and agreed final damages (it being agreed that it would be impractical or
extremely difficult to fix the actual damages), a sum equal to the amount by
which Rent reserved in this Lease for the period which otherwise would have
constituted the unexpired portion of the term EXCEEDS the then fair and
reasonable rental value of the Premises for the same period, both discounted to
present worth at the rate of four (4%) per cent per annum, LESS the aggregate of
Deficiency installments previously collected by Landlord for the same period.
If, before presentation of proof of such liquidated damages to any court,
commission or tribunal, the Premises (or any part thereof) shall have been relet
for the period which otherwise would have

                                       41
<PAGE>

constituted the unexpired portion of the Term, the amount of rent reserved upon
such reletting shall be deemed prima facie evidence of the fair and reasonable
rental value for the part or the whole of the Premises so relet during the term
of such reletting.

     H.  Landlord may bring Legal Proceedings from time to time, at Landlord's
election, for the recovery of damages, or for a sum equal to any installment or
installments of Rent or any Deficiency or other sum payable by Tenant to
Landlord pursuant to this Section, and nothing in this Lease shall require
Landlord to wait for any such purpose until the date originally scheduled for
termination of the Term.

     I.  Nothing in this Lease shall limit or prejudice Landlord's right to
prove and obtain as liquidated damages in any bankruptcy, insolvency,
receivership, reorganization or dissolution proceeding an amount equal to the
maximum allowed by any applicable law at the time when such damages are to be
proved, whether such amount is greater, equal to, or less than, the amount of
damages otherwise specified in this Section.

     J.  No receipt and/or retainage of moneys by Landlord from Tenant after the
giving of a Termination Notice, or after a termination of this Lease, shall
reinstate, continue or extend the Term or affect any Termination Notice or other
written notice, previously given to Tenant, or operate as a waiver of Landlord's
right to enforce payment of Rent then or subsequently becoming due, or operate
as a waiver of Landlord's right to recover possession of the Premises.  Tenant
agrees that after the giving of a Termination Notice or commencement of summary
proceedings or other Legal Proceeding, or after final order or judgment for
possession of the Premises, Landlord may demand, receive and collect all moneys
without invalidating or rescinding such Termination Notice, Legal Proceeding,
order, suit or judgment; and at Landlord's election, all moneys so collected
shall be deemed payments either on account of the use and occupancy of the
Premises or on account of Tenant's liability hereunder.

     K.  In the event Tenant is dispossessed by judgment or warrant of any
court, or in the event of re-entry or repossession by Landlord or in the event
of expiration or any termination of this Lease or Tenant's right of possession
hereunder, Tenant (on behalf of Tenant and all Persons claiming by, through, or
under Tenant) hereby expressly waives:

         (i)    service of any notice of intent to re-enter now or hereafter
                provided by law for such purpose;

         (ii)   any and all rights of redemption now or hereafter provided by
                law; and

         (iii)  any re-entry or repossession or right to restore the Term or
                legal continuance of this Lease.

Tenant expressly waives the service of any notice or demand whatsoever, except
those notices required by this Section 18, and agrees that the simple breach of
any covenant or provision of this

                                       42
<PAGE>

Lease by Tenant shall, of itself, without the service of any other notice or
demand whatsoever, except those notices specifically required by this Section
18, constitute a Default and a forcible detainer by Tenant of the Premises
within the meaning of the statutes of the State of Illinois.

     L.  The terms "enter", "re-enter", "entry" or "re-entry", as used in this
Lease, are not restricted to their technical legal meaning.  If Landlord
commences any summary proceeding or other Legal Proceeding for non-payment of
Rent, Tenant will not interpose and does hereby waive the right to interpose any
counterclaim of whatever nature or description in any such proceeding.

     M.  No failure by Landlord to insist upon the strict performance of any
covenant agreement, term or condition of this Lease or to exercise any right or
remedy after any Default, and no acceptance of the payment of full or partial
Rent during the continuance of any Default shall constitute a waiver of any such
covenant, agreement, term or condition of this Lease to be performed or complied
with by Tenant, and no Default, shall be waived, altered or modified except by a
written instrument executed by Landlord.  No waiver of any default shall affect
or alter this Lease, but each and every term, covenant, condition and provision
of this Lease shall continue in full force and effect with respect to any other
then existing or subsequent Default.

     N.  [INTENTIONALLY DELETED]

     O.  (i)  Tenant shall pay upon demand all Landlord's costs, charges and
expenses, including the reasonable fees and out-of-pocket expenses of counsel,
agents and others retained by Landlord (including costs of appeal and judgment),
incurred by Landlord in successfully enforcing Tenant's obligations hereunder or
incurred by landlord in any legal proceeding, negotiation or transaction in
which Tenant causes Landlord, without Landlord's fault, to become involved or
concerned.

         (ii)  Landlord shall pay upon demand all Tenant's costs, charges and
               expenses including the reasonable fees and out-of-pocket expenses
               of counsel, agents and others retained by Tenant (including costs
               of appeal and judgment) incurred in successfully enforcing
               Landlord's obligations hereunder or incurred by Tenant in any
               legal proceeding, negotiation or transaction in which Landlord
               causes Tenant without Tenant's fault to become involved or
               concerned.

     P.  [INTENTIONALLY DELETED].

     Q.  In the event of any threatened breach by Tenant of any term, covenant,
condition or provision of this Lease, Landlord shall be entitled to enjoin such
Default or threatened breach and shall have the right to invoke all rights and
remedies allowed at law or in equity as though this Lease did not provide for
re-entry, summary proceedings, or other remedies.

     R.  Each right and remedy of Landlord in this Lease shall be cumulative and
in addition to every other right or remedy in this Lease, or now or hereafter
existing at law or in equity; and the

                                       43
<PAGE>

exercise (or beginning of exercise) by Landlord of any one or more rights or
remedies shall not preclude the simultaneous or later exercise by Landlord of
any and all other rights or remedies.

19.  EMINENT DOMAIN.  A. If the Property, or any portion thereof which includes
a substantial part of the Premises, shall be taken or condemned by any competent
authority for any public use or purpose, the term of this Lease shall end upon,
and not before, the date when the possession of the part so taken shall be
required for such use or purpose, and without apportionment of the award. Rent
shall be apportioned as of the date of such termination. If a substantial part
of the Property other than the Premises shall be taken or condemned by any
competent public authority for any public use or purpose, Landlord shall have
the right in Landlord's reasonable opinion to cancel this Lease upon not less
than 180 days' notice prior to the date of cancellation designated in the
notice. No money or other consideration shall be payable by Landlord to Tenant
for said cancellation, and the Tenant shall have no right to share in the
condemnation award or in any judgment for damages caused by said eminent domain
proceeding and any right of Tenant to receive the proceeds of any such award are
hereby assigned to Landlord, except as hereinafter provided.

     B.  Provided, however, that to the extent (a) Tenant is entitled under the
law to receive a separate award in a separate proceeding, following or apart
from the determination of the award for other interests in Property, in respect
of (i) the unamortized value of any existing improvements made by Tenant and
which Tenant is permitted to remove under this Lease (but only if such
improvements were (A) not paid for in whole or part by Landlord or any
contribution from Landlord, and (B) were proven in such proceeding to have
enhanced the value of the Building at least to the extent of such unamortized
value), or (ii) for moving or for business interruption, and (b) such separate
award does not reduce the award otherwise payable to Landlord or the fee owner
of the Land or Building, then Tenant shall be entitled to such an award which it
claims, proves and receives at its own expense.  Tenant's rights under this
paragraph shall be subject to the rights of Landlord and any Superior
Encumbrance to any award for eminent domain.

20.  SUBORDINATION AND SUPERIORITY OF THIS LEASE. This Lease shall be prior to
any Superior Encumbrance, subject to the terms and conditions of this Section,
Tenant agrees to subordinate its rights hereunder at all times to any Superior
Encumbrance and to execute evidencing such subordination as may be required by
the mortgagee or ground or underlying lessor, as the case may be, and to attorn
to and to recognize, as Landlord, the purchaser at a foreclosure sale or the
mortgagee or its nominee in the event the mortgagee or such nominee in the event
the mortgagee or such nominee accepts a deed in lieu of foreclosure, or the
ground or underlying lessor in the event of termination of such underlying or
ground lease, in return for and upon delivery to Tenant by such purchaser or
such mortgagee or its nominee or the ground or underlying lessor, as the case
may be, of an agreement providing that in the event of a foreclosure of such
mortgage or the giving of the deed in lieu of foreclosure or a termination of
such ground or underlying lease, this Lease shall not be terminated and Tenant
may remain in possession of the Premises pursuant to the terms of this Lease and
retain all the rights, options and privileges granted to it hereunder as long
Tenant is not in Default hereunder and continues to perform its obligations
hereunder and further providing that the purchaser at a foreclosure sale or
transferee in the case of a deed given in lieu of foreclosure or

                                       44
<PAGE>

ground or underlying lessor, as the case may be, will assume all of the
obligations of the Landlord in such case; provided, however, that in no event
shall the mortgagee, said purchaser at a foreclosure sale, said transferee in
the case of a deed given in lieu of foreclosure or ground or underlying lessor,
as the case may be, have any personal liability whatsoever hereunder for its own
acts or omissions or obligations; and further provided that the mortgagee, said
purchaser at a foreclosure sale or said transferee in the case of a deed given
in lieu of foreclosure or ground or underlying lessor, as the case may be, shall
also have no personal liability for the acts or omissions or obligations of
Landlord arising or to be performed prior to any such sale or transfer of the
Land or Building to such party except to the extent such acts or omissions or
obligations of Landlord continue after foreclosure or a foreclosure sale
including, without limitation, any liability for any deposits made by the Tenant
hereunder, unless such deposits have been transferred to such party; and
provided, further, that the mortgagee, said purchaser at a foreclosure sale,
said transferee in the case of a deed given in lieu of foreclosure or ground or
underlying lessor, as the case may be, shall be subject to any offsets or
defenses which Tenant might have against any prior Landlord pursuant to Tenant's
rights as set forth in Sections 7 or 35 hereof. Such agreement may, among other
things, require the Tenant to notify the mortgagee or the ground or underlying
lessor of any default by the Landlord and afford such mortgagee the opportunity
to cure such default prior to any termination of this Lease by Tenant (as
provided in Section 28) provided that the Premises are reasonably usable by
Tenant for its normal business activities. Tenant further agrees that, except as
to secondary mortgage financing expressly permitted in such mortgage or ground
or underlying lease, it will not, without the consent of the mortgagee or ground
or underlying lessor, as the case may be, voluntarily subordinate this Lease to
any lien or encumbrance without the consent of said mortgagee or ground or
underlying lessor, as the case may be.

21.  SPRINKLERS. If state or city government or any fire insurance underwriters
for fire insurance for the Property, requires or recommends that any changes,
modifications, alterations or additional sprinkler heads or other equipment be
made or supplied by reason of Tenant's business or the location of partitions,
trade fixtures, or other contents of the Premises, or for any other reason, or
if any such changes, modifications, alterations, additional sprinkler heads or
other equipment, become necessary to prevent the imposition of a penalty or
charge against the full allowance for a sprinkler system in the fire insurance
rate as fixed by said underwriters, or by any fire insurance company, Tenant
shall, at Tenant's expense, promptly make and supply such changes,
modifications, alterations, additional sprinkler heads or other equipment.

22.  LANDLORD'S MAINTENANCE.  Landlord, as an Operating Expense, shall keep and
maintain the Building and its fixtures, appurtenances, systems and facilities
serving the Premises, in good working order, condition and repair and shall make
all repairs, structural and otherwise, interior and exterior, as and when needed
in or about the Building and the Premises, except for those repairs for which
Tenant is responsible pursuant to any other provisions of this Lease. Without
limiting the generality of the foregoing, Landlord shall repair and maintain,
and if necessary, replace (i) Building structure, foundation, roof, gutters,
exterior walls, window coverings, windows, and all other exterior and structural
parts of the Building, (ii) halls, stairways and entryways, elevators and common

                                       45
<PAGE>

passageways and all other common areas of the Building, (iii) premises occupied
by other tenants to the extent necessary to prevent any damage to the Premises,
and (iv) all elements of the plumbing system, the sprinkler system, the light
fixtures and electrical distribution system, the heating, ventilating and air
conditioning system and any other of the Building's shared systems located
within the Premises, and any damage caused to any items in the Premises which
would become the property of the Landlord upon termination of this Lease by any
malfunction or misfunction of such systems, except only for any supplementary
portions of such systems owned by Tenant. Nothing contained in this Section 22
shall require Landlord to paint or decorate the Premises. No liability of
Landlord to Tenant shall accrue however under subparagraphs (iii) and (iv) above
unless and until Tenant has given written (except in the case of an emergency)
notice to Landlord of the specific repair required to be made or of the failure
to properly furnish any service and Landlord does not promptly thereafter
undertake and diligently pursue such repair or furnish such service. Landlord
shall have no obligation to maintain, repair or replace the pedestrian bridge
described in Section 37.

23.  NOTICE.  In every instance where it shall be necessary or desirable for
Tenant to give or serve any notice or demand upon Landlord, such notice or
demand shall be in writing and sent by United States Registered or Certified
Mail (return receipt requested), postage prepaid or by a commercial courier,
prepaid, addressed to Landlord c/o the Rental Agent at the place where rental
under this Lease is then being paid.  Any notice or demand to be given or served
by Landlord to Tenant shall be effective if mailed or delivered by Landlord or
Landlord's Rental Agent to The Northern Trust Company 50 South LaSalle Street
Chicago, IL  60675, Attention: Vice President Corporate Real Estate with a copy
to:  The Northern Trust Company, 50 S. LaSalle Street, Chicago, IL  60675,
Attention: General Counsel.  Notice mailed as aforesaid shall be conclusively
deemed to have been served at the close of the second business day following the
date said notice was mailed; notice delivered by courier as aforesaid shall be
conclusively deemed to have been received at the close of the first business day
following the date said notice was given to the courier.

24.  SUCCESSORS AND ASSIGNS.  Each provision hereof shall extend to and shall,
as the case may require, bind and inure to the benefit of Landlord and Tenant
and their respective heirs, legal representatives, successors and assigns,
provided that this Lease shall not inure to the benefit of any assignee, heir,
legal representative, transferee or successor of Tenant except any permitted
assignee as provided in Section 16.

     The term "Landlord", as used in this Lease, means only the owner, or the
mortgagee in possession (including anyone claiming any title or any interest in
the Land or Building by, through or under said mortgage), for the time being, of
the Property (or the owner of a lease of the Building or of the Real Estate and
the Building) of which the Premises form a part, so that in the event of any
conveyance or sale of said Real Estate and the Building (including a sale or
transfer arising by virtue of a foreclosure of any mortgage of the Land or the
Building or any deed given in lieu of foreclosure thereof) or of said Lease, or
in the event of a lease of the Building, or of the Real Estate and the Building,
the seller or lessor shall be and hereby is entirely free and relieved of all
covenants, obligations and liabilities of Landlord hereunder, and it shall be
deemed and construed as a covenant running with the land without further
agreement between the parties or their successors in interest,

                                       46
<PAGE>

or between the parties and the purchaser at any such sale, or the said lessee of
the Building, or of the Real Estate and the Building, provided that the
purchaser or the lessee of the Building, as applicable, has (subject to the
provisions of Section 20) assumed and agreed to carry out any and all covenants,
obligations and liabilities of Landlord hereunder.

25.  INSURANCE.

     A.  Landlord and Tenant agree to have all property insurance policies which
may be carried by either of them, and Tenant agrees to have all business
interruption insurance carried by it, endorsed with a clause providing that any
release from liability of or waiver of claim for recovery from the other party
entered into in writing by the insured thereunder prior to any loss or damage
shall not affect the validity of said policy or the right of the insured to
recover thereunder, and providing further that each insurer waives all rights of
subrogation which such insurer may have against the other party.  Without
limiting any release or waiver of liability or recovery contained in any other
paragraph of this Lease, but rather in confirmation and furtherance thereof,
Landlord and Tenant each hereby waive and release any and every claim for
recovery from the other, its officers, agents, employees and beneficiaries for
any and all loss of or damage to the Property or to the contents thereof or
damages as a result of business interruption, which loss or damage is covered by
valid and collectible fire and extended coverage insurance policies, to the
extent that such loss or damage is recoverable by the party giving the waiver
under said insurance policies, or would have been recoverable by the party
giving the waiver had it carried the insurance required of it under this Lease.
Inasmuch as this mutual waiver will preclude the assignment of any such claim by
subrogation (or otherwise) to an insurance company (or any other Person),
Landlord and Tenant each agree to give to each insurance company which has
issued, or in the future may issue, to it such property and business
interruption insurance policies, written notice of the terms of this mutual
waiver, and to have said insurance policies properly endorsed, if necessary, to
prevent the invalidation of said insurance coverage by reason of said waiver.

     B.  At all times during the Term of this Lease, Tenant shall at its sole
cost and expense maintain in full force and effect insurance protecting Tenant
and Landlord and its respective agents and any other Persons reasonably
designated by Landlord from time to time, with terms, coverages and in companies
at all times reasonably satisfactory to Landlord and with such increases in
limits as Landlord may, from time to time, reasonably request.  Initially, such
coverage shall be in the following amounts:

         (i)     Commercial Liability Insurance, including Contractual Liability
                 insuring the indemnification provisions contained in this
                 Lease, with limits of not less than Three Million Dollars
                 ($3,000,000.00) combined single limit per occurrence for Bodily
                 Injury, Death and Property Damage. The liability policy shall
                 include as an additional insured the Landlord, with a
                 severability of interest endorsement.

                                       47
<PAGE>

         (ii)    Insurance against (A) "All Risks", "Special Form" or comparable
                 coverage of physical loss coverage for all betterments and
                 improvements to the Premises, including alterations, and
                 including any improvements or betterments made by Tenant
                 outside the Premises (including the pedestrian bridge described
                 in Section 37) whether in existence upon execution of this
                 Lease or made hereafter, the entire replacement cost from time
                 to time of all movable fixtures, office equipment, furniture,
                 trade fixtures, merchandise and all other items of Tenant's
                 property on the Premises; plus valuable papers insurance
                 covering documents and papers of value in Tenant's vaults with
                 limits not less than those customarily carried by prudent
                 tenants in such businesses and (B) loss of use of the Premises.

     Insurance carried by Tenant shall be with insurers licensed to do business
in the State of Illinois, have a Best's (or comparable rating entity's)
financial rating of A and a financial size of X or higher.

     C.  The policy referred to in Section 25B(i) shall name Landlord,
Landlord's Building manager and their respective agents and employees (and the
holder of a Superior Encumbrance, if required by such holder) as additional
insureds, and the policy in Section 25B (ii)(A) shall insure Landlord as its
interests may appear and the holder of any Superior Encumbrance under a standard
mortgagee clause.

     D.  Tenant shall, prior to the earlier of (a) the Commencement Date, or (b)
the entry upon the Premises by Tenant or its Employees or contractors, and prior
to the expiration of any policy, furnish Landlord with certificates evidencing
that all required insurance is in force and providing that such insurance may
not be canceled or changed without at least thirty (30) days' prior written
notice to Landlord and Tenant (ten (10) days' in case of non-payment of
premium).  All policies shall contain a provision that no act or omission of
Tenant shall affect or limit the obligation of the insurer to pay the amount of
any loss sustained.

     E.  Tenant and Landlord shall cooperate with each other and with the holder
of any Superior Encumbrance in connection with collection of any insurance
monies.

     F.  All insurance of Tenant shall be primary and not contributory with any
insurance of Landlord.  Tenant shall not secure separate insurance concurrent in
form or contributing in the event of loss with any insurance policy required
under this Lease unless Landlord is included as a named insured with loss
payable to Landlord.  Tenant shall give Landlord written notice promptly upon
securing any such separate insurance, specifying the insurer and full
particulars of applicable policies.

     G.  Tenant shall, before seeking any recovery from Landlord or Landlord's
insurer, recover all sums payable by Tenant's insurer. For purposes of Tenant's
waiver of claims in Section 25A of this Lease, any deductible in excess of
$5,000 shall be deemed to be self-insured and, for purpose of
                                       48
<PAGE>

any waiver of claims, any such excess deductible or other self-insurance shall
be deemed to have been recoverable under insurance carried by Tenant.

     H.  Tenant shall not do or permit to be done any act or thing upon the
Premises which will invalidate any insurance policy or be in conflict with any
insurance requirements, or increase the rate of fire insurance premium
applicable to the Building, or necessitate Landlord's carrying of additional
insurance coverage; and Tenant shall not do or permit to be done any act or
thing upon the Premises which will or might subject Landlord to any liability or
responsibility for injury to any Person or to property.  Tenant shall reimburse
Landlord, as additional Rent upon demand, for all increases of Landlord's
insurance premiums resulting from violations of Tenant's obligations under this
Section.  In any Legal Proceeding involving the cost of insurance, a schedule or
"make-up" of rates issued by the body making insurance rates for the Building or
the Premises shall be presumptive evidence of the items and charges taken into
consideration in fixing the insurance rates then applicable to the Premises or
the Building.

     I.  At all times during the Term of this Lease, Landlord shall carry
insurance with commercially reasonable deductible amounts and with reputable and
solvent insurance companies authorized to do business in Illinois in the
following amounts: (i) "all-risk" or "special form" replacement cost property
insurance on the Building against fire and other extended coverage perils
(including boiler and machinery and electrical apparatus coverage) in an amount
sufficient to prevent Landlord from being deemed a co-insurer of the risks
insured under the policy, (ii) commercial liability insurance, including
contractual liability, in an amount not less than $3,000,000.00 per occurrence.

26.  MISCELLANEOUS.

     A.  Wherever there is provided in this Lease a time limitation for
performance by the Landlord or Tenant of any construction, repair, maintenance
or service, the time provided for shall be extended for as long as and to the
extent that delay in compliance with such limitation is due to an act of God,
public enemy, strikes, governmental control, fire, flood, quarantine
restriction, freight embargo, shortage of materials or labor, or other factors
beyond the reasonable control of the Landlord or Tenant.

     B.  If any provision of this Lease or application to any party or
circumstances shall be determined by any court of competent jurisdiction to be
invalid and unenforceable to any extent, the remainder of this Lease and the
application of such provision to such person or circumstances, other than those
as to which it is so determined invalid or unenforceable to any extent, shall
not be affected thereby, and each provision hereof shall be valid and shall be
enforced to the fullest extent permitted by law.

     C.  The headings of sections are for convenience only and do not define,
limit or construe the contents of such sections or subsections.  References made
in this Lease to numbered sections and

                                       49
<PAGE>

subsections shall refer to the numbered sections or subsections of this Lease,
unless otherwise indicated.

     D.  The Lease is to be executed in copies, each of which executed copy
shall constitute an original.

     E.  Each of the parties agrees, at the request of the other, to execute
such instruments or documents as any party may reasonably request,
acknowledging: the date of completion of construction of Premises; the date of
acceptance of possession of Premises; the date of commencement of Rent; the
commencement of the Term; the commencement and expiration dates of this Lease;
Tenant's Proportionate Share of the Operating Expenses, Taxes, Operating Expense
Deposits for any Lease Year; the number of rentable square feet demised to the
Tenant; Base Rent amount; and the compliance or noncompliance by any party with
any of the terms or provisions of this Lease; and to evidence such other or
further matters as may be so reasonably requested by Tenant or Landlord.

     F.  Tenant represents to Landlord, and Landlord represents to Tenant, that
except for Douglas Elliman-Beitler and Staubach Midwest L.L.C., the representing
party has not dealt with any real estate broker in connection with this Lease
and, to its knowledge, no broker other than Douglas Elliman-Beitler and Staubach
Midwest L.L.C. initiated or participated in the negotiation of this Lease,
submitted or showed the Premises or any other space in the Building to Tenant or
is entitled to any commission or fee in connection with this Lease.  Tenant
hereby agrees to indemnify, defend, and hold Landlord harmless from and against
any and all claims of any other real estate broker for commissions or fees in
connection with this Lease who claim to have dealt with the Tenant or Staubach
Midwest L.L.C. not in accordance with its commission agreement with Landlord
entered into prior to the date of this Lease.  Landlord hereby agrees to
indemnify, defend and hold Tenant harmless from and against any and all claims
of any other real estate broker for a commission or fee in connection with this
Lease who claims to have dealt with Landlord.

     G.  No receipt of money by Landlord from Tenant after the termination of
this Lease, the service of any notice, the commencement of any suit or final
judgment for possession shall reinstate, continue or extend the term of this
Lease or affect any such notice, demand, suit or judgment.

     H.  No waiver of Default of Tenant shall be implied, and no express waiver
shall affect any Default other than the Default specified in such waiver and
then only for the time and to the extent therein stated.  No agreement to accept
a surrender of this Lease shall be valid unless in writing signed by Landlord.
No Employee of Landlord shall have any power to accept the keys of the Premises
prior to the expiration of the Term.  The delivery of keys to any Employee of
Landlord shall not operate as a termination of this Lease or an acceptance of a
surrender of the Premises.  If Tenant, at any time, desires to have Landlord
sublet the Premises for Tenant's account, Landlord is authorized to receive said
keys for such purpose without releasing Tenant from any of the obligations under
this Lease.  The failure of Landlord to seek redress for violation of, or to
insist upon the strict performance of, any covenant or condition of this Lease
or any of the rules and regulations (now or

                                       50
<PAGE>

hereafter in effect) shall not prevent a subsequent act, which would have
originally constituted a violation, from having all the force and effect of an
original violation. The receipt by Landlord of Rent with knowledge of the breach
of any covenant of this Lease shall not be deemed a waiver of such breach.

     I.  Clauses, plats, exhibits and riders, if any, affixed to this Lease are
part hereof and in the event of variation or discrepancy, the duplicate original
hereof, including such clauses, plats and riders, if any, held by Landlord shall
control.

     J.  Submission of this instrument for examination or signature by Tenant
does not constitute a reservation of or option for lease, and it is not
effective as a lease or otherwise until execution and delivery by both Landlord
and Tenant.  Submission of this instrument to Landlord, signed by Tenant, shall
constitute an irrevocable offer to lease the Premises on the terms herein stated
to and including November 30, 2000.

     K.  Wherever the consent of either Landlord or Tenant is required by the
provisions of this Lease, such party shall not unreasonably withhold, condition,
or delay such consent.

     L.  No modifications, termination or surrender of this Lease or surrender
of the Premises or any part thereof or of any interest therein by Tenant shall
be valid or effective unless agreed to and accepted, in writing, by Landlord,
and no act by any representative or agent of Landlord, other than delivery of
such a written agreement and acceptance by Landlord shall constitute an
acceptance thereof.

     M.  This Lease shall be construed and enforced in accordance with the laws
of the State of Illinois.

     N.  As used herein, the terms "Landlord" or "Tenant" and any pronouns used
to refer to Landlord or Tenant shall, as the context requires, include the
singular and the plural, and the masculine, feminine and neuter.

     O.  This Lease has been jointly negotiated and reviewed by all of the
parties hereto and shall be construed accordingly; any principle or rule of
construction which construes any provision of this Lease against the draftor of
the Lease is hereby declared to be inapplicable to this Lease and all parties to
this Lease.

     P.  Except as otherwise expressly provided in this Lease, each covenant,
agreement, obligation or other provision of this Lease on Tenant's part to be
performed shall be deemed and construed as a separate and independent covenant
of Tenant, not dependent on any other provision of this Lease.

     Q.  Time shall be of the essence with respect to every provision under this
Lease.

                                       51
<PAGE>

     R.  [INTENTIONALLY DELETED].

     S.  This Lease and the exhibits attached hereto represent the entire
agreement between the parties hereto relating to the subject matter hereof and
all prior agreements, representations and understandings, either oral or
written, are merged herein.

     T.  This Lease shall not be recorded; provided, however, at the request of
either party, Landlord and Tenant shall execute a short form of this Lease
containing the Premises and Term in the form of Exhibit N (and terminate any
existing short form or memorandum of lease) for the purpose of giving record
notice of this Lease and Tenant's possession or amend any existing recorded
short form lease to reflect the present premises and term.

27.  ESTOPPEL CERTIFICATES.  The Tenant agrees that, from time to time upon not
less than ten (10) business days prior written request by Landlord, the Tenant,
or Tenant's duly authorized representative having knowledge of the following
facts, will deliver to Landlord a statement in writing certifying: (i) that this
Lease is unmodified and in full force and effect (or if there have been
modifications that the Lease, as modified, is in full force and effect); (ii)
the dates to which Rent and other charges have been paid; (iii) to the knowledge
of Tenant, that the Landlord is not in default under any provision of this
Lease, or, if in default, the nature thereof in detail, and (iv) as to such
other matters as may be reasonably requested by Landlord relating to the status
of the Lease, it being intended that any such statement may be relied upon by
any prospective purchaser or tenant of the Property, any mortgagees or
prospective mortgagees thereof, or any prospective assignee of any mortgage
thereof. Tenant shall execute and deliver the form of Estoppel Certificate
attached hereto as Exhibit E, or such other form required by Landlord meeting
criteria set forth above as is reasonably acceptable to Tenant. In the event
Tenant fails so to do within twenty (20) business days after demand in writing,
Tenant shall be considered in Default under this Lease, or at Landlord's option,
the failure to deliver such instruments within such time shall be conclusive
upon Tenant that this Lease is in full force and effect, without modification
except as may be represented by Landlord, there are no uncured defaults by or
defenses or claims against Landlord and that not more than one (1) month's
rental has been paid in advance and Tenant shall be estopped from asserting any
defaults, defenses or claims known to it at that time. In the event that any
existing or prospective purchaser or holder of a Superior Encumbrance requires
information from Tenant in order to comply with the rules and regulations of the
Employee Retirement Income Security Act ("ERISA"), Tenant shall promptly
represent to such holder such information as such holder may reasonably require
in order to determine its compliance with ERISA requirements and Tenant shall
indemnify such holder against any inaccuracy in such representation.

28.  MORTGAGEE PROTECTION. Tenant will pay no Rent under this Lease more than
thirty (30) days in advance of its due date other than Operating Expense
Deposit, unless otherwise agreed by the holder of any Superior Encumbrance.

     Tenant shall give the holder of any Superior Encumbrance whose name and
address shall have been given in writing to Tenant a copy of any notice of
default or claim given by Tenant to Landlord,

                                       52
<PAGE>

such notice to be given by registered or certified mail or by commercial
courier. Tenant will not exercise any right which it may have to terminate this
Lease, or abate Rent or set off any amounts against Rent unless Tenant first
gives written notice of such act or omission to the holder of each such Superior
Encumbrance and gives the holder of the Superior Encumbrance at least thirty
(30) days after the giving of such notice to remedy such act or omission, plus
the time to obtain possession if possession is necessary to remedy such act or
omission (during which time such holder shall have the right, but no obligation,
to remedy the alleged act or omission). Tenant agrees, further, not to exercise
any such right if the holder of any such Superior Encumbrance commences to cure
such act or omission within thirty (30) days after such notice and diligently
prosecutes such cure to completion.

29.  LANDLORD'S COMPLIANCE WITH LAW.

     A.  Landlord shall be responsible for keeping those portions of the core
and shell of the Building (the term "core and shell" not deemed to include
improvements and betterments to any tenant's premises, including the Premises)
in compliance with Laws, whose condition, if a violation existed, would
materially affect Tenant's use and occupancy of the Premises for office use or
subject Tenant to criminal liability, fines or penalties.  The foregoing
obligation on the part of Landlord shall not limit the obligations of Tenant as
set forth in the this Lease, or in any other provision of the Lease requiring
Tenant to repair damage caused by it or its employees, agents or contractors, or
to make alterations required by any Law which affect Tenant or the Premises
solely by reason of its manner of use of the Premises.

     B.  Landlord shall have responsibility for compliance with Title III of the
provisions of the Americans With Disabilities Act of 1990 ("ADA") and
regulations promulgated thereunder applicable to Building common areas
(including Building entrances, lobbies, hallways not located in tenants' spaces
and corridors, restrooms, public elevators), and Tenant shall have
responsibility for compliance with ADA as to the entrances to and interior of
the Premises.  If as a result of Tenant's alterations and additions or
particular use of the Premises (other than general office use), Landlord is
required to alter common areas, Tenant shall pay the cost of such alterations.

     C.  During the term of the Lease, Landlord shall fully comply with any
Environmental Laws.  Landlord shall not cause or permit its business in the
Premises to be used to generate, manufacture, refine, transport, treat, store,
handle, dispose, transfer, produce or process Hazardous Materials, except in
compliance with all Environmental Laws.  Landlord shall notify Tenant if it
receives a notice of Landlord's violation of Environmental Laws if such
violation would affect Tenant's safe occupancy of the Premises.  Landlord shall
obtain all necessary permits under Environmental Laws and shall make them
available for inspection by Tenant, at Tenant's written request.  Landlord, for
itself and its successors and assigns, shall indemnify, defend and hold Tenant
harmless from and against any claims, demands, liabilities and damages
(including, but not limited to, attorneys' fees and court costs) arising out of
or in connection with Landlord's violation of Environmental Laws.  The
obligations of this paragraph shall survive the expiration or termination of
this Lease.

                                       53
<PAGE>

     D.  Landlord, at its expense, may contest the validity of any Laws and
postpone compliance therewith pending such contest (so long as Tenant is not
subject to criminal proceeding criminal investigation, criminal liability, fines
or penalties as a result).  If Tenant receives written notice of any violation
of any Laws applicable to the Premises, it shall give prompt notice thereof to
Landlord.

     30.  INDEMNIFICATION BY TENANT.

     A.  Tenant hereby agrees, to the fullest extent permitted by Law, to
indemnify each and every Indemnitee and hold each and every Indemnitee harmless
from and against (and to pay the full amount of) all loss, liability,
obligation, damage, penalty, tax, cost, claim, demand, judgment, charge or
expense of every kind whatsoever which any Indemnitee may suffer, incur, or pay
out, or which may be asserted against any Indemnitee, in whole or in part, by
reason of, or in connection with:

         (i)   any Legal Proceeding brought by Tenant against Landlord (or any
               officer, partner, or Employee of Indemnitee) in which Tenant
               fails to secure a judgment against Indemnitee, final beyond
               appeal; and

         (ii)  any negligent or willful act or omission of Tenant or Tenant's
               Employees or invitees (to the extent not waived pursuant to the
               provision of Section 25A).

         (iii) use of Tenant's name on the Building (if named for Tenant under
               Section 47).

     B.  Tenant shall defend any and all Legal Proceedings commenced against
Indemnitee by any Person (other than Tenant) concerning any matter which may or
might be covered by any indemnity or obligation under Subsection 31A (ii) (i.e.,
regardless of any alleged fault or cause) using counsel reasonably acceptable to
Landlord (provided that counsel of the insurance company shall be deemed
acceptable), and Landlord shall have the right, but not the obligation, to
participate in such defense with counsel of its choice.  Tenant shall deliver to
Landlord copies of documents served in any such Legal Proceeding and, whenever
requested by Landlord, shall advise as to the status of such Legal Proceeding.
If Tenant fails to defend diligently any such Legal Proceeding, or if Landlord
elects to defend by written notice to Tenant at any time, Landlord shall have
the right (but no obligation) to defend the same at Tenant's expense.  Tenant
shall not settle any such Legal Proceeding without a release of Landlord without
Landlord's prior written consent.

     C.  Tenant shall notify Landlord and all applicable insurers immediately of
every Legal Proceeding or claim which may or might be covered by any indemnity
under this Section and/or by any required insurance.

                                       54
<PAGE>

31.  INDEMNIFICATION BY LANDLORD.

     A.  Landlord hereby agrees, to the fullest extent permitted by law, to
indemnify Tenant and hold Tenant harmless from and against (and to pay the full
amount of) all loss, liability, obligation, damage, penalty, tax, cost, claim,
demand, judgment, charge or expense of every kind whatsoever which Tenant  may
suffer, incur, or pay out, or which may be asserted against Tenant, in whole or
in part, by reason of, or in connection with:

         (i)   any Legal Proceeding brought by Landlord against Tenant (or any
               officer, partner, or Employee of Tenant) in which Landlord fails
               to secure a judgment against Tenant, final beyond appeal; and

         (ii)  any negligent or willful act or omission of Landlord or
               Landlord's Employees or invitees (to the extent not waived
               pursuant to the provisions of Section 25A).

     B.  Landlord shall defend any and all Legal Proceedings commenced against
Tenant by any Person (other than Landlord) concerning any matter which may or
might be covered by any indemnity or obligation under Subsection 30A(ii) (i.e.,
regardless of any alleged fault or cause) using counsel reasonably acceptable to
Tenant (provided that counsel of the insurance company shall be deemed
acceptable), and Tenant shall have the right, but not the obligation, to
participate in such defense with counsel of its choice.  Landlord shall deliver
to Tenant copies of documents served in any such Legal Proceeding and, whenever
requested by Tenant, shall advise as to the status of such Legal Proceeding.  If
Landlord fails to defend diligently any such Legal Proceeding, or if Tenant
elects to defend by written notice to Landlord at any time, Tenant shall have
the right (but no obligation) to defend the same at Landlord's expense.
Landlord shall not settle any such Legal Proceeding without a release of Tenant
without Tenant's prior written consent.

     C.  Landlord shall notify Tenant and all applicable insurers immediately of
every Legal Proceeding or claim which may or might be covered by any indemnity
under this Section or by any required insurance.

32.  POSSESSION. Tenant is presently in possession of the Existing Premises.

33.  EXONERATION CLAUSE.

     A.  This Lease is executed by the undersigned, LaSalle Bank National
Association, not personally, but as Trustee in the exercise of the power and
authority conferred upon and vested in it as such Trustee and under the express
direction of the beneficiaries of the said Trust.  It is expressly understood
and agreed that all of the warranties, indemnities, representations, covenants,
undertakings and agreements herein made on the part of the Trustee are
undertaken by it solely in its capacity as Trustee and not personally.  No
personal liability or personal responsibility is assumed by

                                       55
<PAGE>

or shall at any time be asserted or enforceable against the Trustee on account
of any warranty, indemnity, representation, covenant, undertaking or agreement
of the Trustee in this instrument.

     B.  Tenant agrees to look solely to Landlord's interest in the Property, or
the lease of the Building or of the Property, and the Premises, for the
satisfaction of any right or remedy of Tenant for the collection of a judgment
(or other judicial process) requiring the payment of money by Landlord, in the
event of any liability by Landlord, and no other property or assets of Landlord
or Landlord's Affiliates shall be subject to levy, execution, attachment, or
other enforcement procedure for the satisfaction of Tenant's remedies under or
with respect to this Lease, the relationship of Landlord and Tenant hereunder,
or Tenant's use and occupancy of the Premises, or any other liability of
Landlord or Landlord's Affiliates to Tenant.

34.  WAIVER OF JURY TRIAL. Tenant and Landlord hereby waive trial by jury in any
Legal Proceeding brought by either against the other with respect to Landlord's
recovery of possession under this Lease, but not otherwise.

35.  LANDLORD DEFAULT AND PERFORMANCE BY TENANT.
     ------------------------------------------

     A.  If Landlord shall at any time default in the performance of any
obligation under this Lease which may be performed solely by the payment of
money, and such default shall continue for ten (10) days after written notice
from Tenant to Landlord, Tenant shall have the right, but shall not be
obligated, to make such payment on behalf of Landlord.  In the event that any
services to be performed by Landlord for Tenant under this Lease shall be
totally suspended and Landlord shall not have commenced and diligently pursued
the repair or restoration of such service within ten (10) days after written
notice to Landlord from Tenant (which period may be extended as a result of
delays described in Section 26A for a period equal to any and such delays), (i)
Tenant shall have the right, but shall not be obligated, to perform such
obligation if such obligation affects the Premises and not the Building
generally, and (ii) Tenant shall have such other rights or remedies allowed by
law.  In performing such obligation under subsection (i) above, Tenant may make
any payment of money or performance any other act related to the repair or
restoration of such service.

     B.  If Landlord shall at any time default in the performance of any other
material obligation under this Lease which materially affects Tenant's ability
to conduct business from the Premises and such default continues for a period of
sixty (60) days after written notice from Tenant to Landlord and the holder of
any Superior Encumbrance (provided, however, that such sixty day period shall be
extended if such default cannot be reasonably cured within such sixty day
period) and Landlord shall have promptly, within such sixty day period
undertaken a cure, and diligently pursues such cure to completion and provided
further that an opportunity to cure shall have been given the holder of a
Superior Encumbrance under Section 28 hereof, Tenant may terminate this Lease or
bring an action in law or equity to recover damages and require Landlord to
perform its obligations hereunder.

                                       56
<PAGE>

     C.  All sums reasonably paid by Tenant pursuant to this Section 35,
together with interest at the rate of 2% per annum over the Prime Rate and all
necessary incidental costs and expenses in connection with the payment or
performance of any such act by Tenant shall be payable to Tenant immediately
upon demand and if not so paid within thirty (30) days after demand and are not
then subject of a good faith dispute between Landlord and Tenant, may be
deducted or set off against any amount (including Rent) due Landlord under this
Lease.  Further, any Allowance, Put Space Allowance or other allowance required
to be paid by Landlord to Tenant for Expansion Space or First Offer Space not
paid when due which is thereafter not paid within thirty (30) days after demand
to Landlord and notice to the holder of a Superior Encumbrance as required under
this Lease, and which is not the subject of a good faith dispute, may be
deducted or set off by Tenant against any amount including Rent due under this
Lease.

     D.  Unless otherwise provided specifically to the contrary, this Lease and
Tenant's obligations to pay Rent and perform all of Tenant's other covenants,
agreements, terms, provisions and conditions hereunder shall not be affected,
impaired or excused because Landlord is unable to furnish or is delayed in
furnishing any work or service whatsoever expressly or implicitly to be
furnished, or is unable to make or is delayed in making any repairs, if Landlord
is prevented, or delayed from so doing by reason of any cause beyond Landlord's
reasonable control (including strikes, governmental preemption in connection
with a national emergency, Laws, failure of utilities or public services, or
severe weather).

36.  MOST FAVORED TENANT.  Tenant is executing this Lease upon Landlord's
     -------------------
representation that Tenant has received the most favorable terms in certain
economic issues under this Lease that Landlord is presently prepared to agree
upon with a "Major Tenant" (a tenant leasing more than 150,000 square fee to
Rentable Area in the Building) for occupancy in the Building.  If within the
period ending eighteen months (18) months after execution of this Lease by
Landlord and Tenant, Landlord agrees, in an executed lease with a Major Tenant,
to give another such Major Tenant more favorable terms than the Rent per RSF
(other than Rent for Extension Premises in effect for the period prior to April
1, 2005) under this Lease, Tenant shall be entitled, in accordance with this
Section, to have this Lease amended by Landlord  to provide for the more
favorable terms.  It is intended that Rent for the Extension Premises for the
period prior to April 1, 2005 not be reduced by operation of this Section.  This
Lease shall be amended to reflect the more favorable terms under the following
conditions:

     A.  Only leases to a Major Tenant for an initial term of ten (10) years or
more ("Qualifying Leases") shall be considered.

     B.  Amendments under this Section shall be made as of the commencement date
of each Qualifying Lease and shall be prospective only.

     C.  Landlord shall submit all Qualifying Leases to Tenant on a confidential
basis for review.  At Tenant's request to Landlord, a certified public
accountant acceptable to both Landlord

                                       57
<PAGE>

and Tenant (the "Accountant") shall be directed, at equal cost to Landlord and
Tenant, to review all Qualifying Leases to evaluate the following economic
issues ("Comparison Matters");

          (i)    Base Rent;

          (ii)   Any other forms of rent, however characterized, including
     adjustments to compensate for inflation, any management fees, stepped
     adjustments and operating expenses and tax pass-throughs, whether on a
     "net" basis or on a "base amount" or "base year" basis;

          (iii)  Tenant inducements, including but not limited to rent
     abatements or concessions, construction allowances and equity
     participations; and

          (iv)   Over-standard tenant services, including parking or storage
     space.

     D.   The accountant shall derive projected net rental cost per RSF for such
Qualifying Lease based on such evaluation of Comparison Matters.  The Accountant
shall then derive a projected net rental cost per RSF for Tenant under this
Lease for the term of the Qualifying Lease, using the same assumptions that were
used in evaluating the Qualifying Lease, including escalations in operating
expenses and taxes, value of equity participation, and discounted value of
money, but assuming a rental rate per RSF not less than that which would be
payable after April 1, 2005.  The Accountant shall complete such analysis within
fifteen (15) business days after such direction.  If such comparison discloses
that Tenant's net rental cost per RSF exceeds the net rental cost per RSF under
the Qualifying Lease, Tenant shall receive a reduction in costs or increase in
benefits adequate to eliminate such excess in a manner satisfactory to Landlord
and Tenant.  If the parties do not agree on the different manner within thirty
(30) days after the Accountant determines such excess, the adjustment shall be
made to Base Rent hereunder.  Any such adjustment shall only be effective during
the term of the Qualifying Lease.  Landlord, in order to evaluate the effect of
a Qualifying Lease under this Paragraph, may submit the relevant terms of a
Qualifying Lease to Tenant prior to its execution.  Tenant must then notify
Landlord in writing within ten (10) days after receipt of such terms if Tenant
reasonably believes such Qualifying Lease is at a net rental cost per RSF less
than Tenant's or Tenant will be deemed to have waived consideration of such
Qualifying Lease.  If Tenant does notify Landlord of its belief, Landlord may
submit the Qualifying Lease for review by the Accountant as described above
prior to signing such Qualifying Lease.  The Accountant's determination shall be
binding and conclusive on Landlord and Tenant whether made before or after a
Qualifying Lease is executed, so long as the terms outlined by Landlord do not
vary from those in the actual Qualifying Lease.

37.  PEDESTRIAN BRIDGE.  Tenant has constructed an enclosed pedestrian bridge
     -----------------
pursuant to the terms of the Existing Lease, from the 7th floor of the Building
to the 5th floor of the building at 50 South La Salle Street ("50 S. LaSalle").
Tenant shall be responsible for installing all necessary Building systems in the
existing or any future bridge and for heating, cooling, insuring and maintaining
any bridge and for providing all necessary security.  The bridge space shall not
be included in Rentable Area for any purpose under the Lease.  At the end of the
Lease term by lapse

                                       58
<PAGE>

of time otherwise, Tenant shall at its sole expense remove each bridge in its
entirety and repair the floor in the Premises and walls to which it was
connected so that it is fully enclosed in like manner to the other floors.
Tenant shall, at its sole expense, maintain, repair or replace each pedestrian
bridge to keep it in safe operating condition. Provided that (i) Tenant complies
with the provisions of Section 8J of the Lease (except for Landlord's consent to
construction of a bridge, which consent is hereby given provided Tenant complies
with the provisions of this Section 37), (ii) the design of each such bridge is
formulated in consultation with the Building engineer and the Building
architect, (iii) the structural integrity of each such bridge is approved by the
Building engineer (which approval shall not be unreasonably withheld conditional
or delayed), and (iv) the aesthetics of each such bridge are approved by the
Building architect (which approval shall not be unreasonably withheld
conditioned or delayed), who may not specify glass as being aesthetically
required, Tenant shall have the right to construct, at its costs, additional
fully enclosed pedestrian bridges between a floor in the Premises and an
equivalent floor at 50 S. LaSalle, or redesign or relocated existing bridges.
Landlord shall cooperate with Tenant in obtaining the necessary municipal and
governmental permits, licenses and consents that may be required in connection
with construction of said bridges.

38.  MONUMENT SIGNAGE.  During the Term of this Lease, as long as, Tenant
     ----------------
leases and occupies at least  25% of Rentable Area in the Building, Tenant may,
at its expense and subject to approvals and the requirements of applicable Laws,
and documents of record, (a) design and construct, a ground level monument sign
(the "Monument Sign") adjacent to the Building located on the Real Estate in a
size, design and location acceptable to both Landlord and Tenant (and approved
by the City of Chicago, if required by the City of Chicago), and (b) use the
Monument Sign solely for Tenant's name and logo to identify Tenant's occupancy
in the Building.  If Tenant ever leases and occupies fewer than the required
percentage of Rentable Area in the Building, Tenant's rights with respect to the
Monument Sign shall thereupon expire and be without further force and effect.
Upon termination of Tenant's rights, Tenant shall remove all Tenant
identification, at Tenant's expense; otherwise, the Monument Sign shall remain
and Landlord may use or permit others to use the Monument Sign.  Tenant shall
maintain and repair the Monument Sign in good and safe condition and in
compliance with all Laws.  Tenant's insurance under Section 25 shall include the
Monument Sign.

39.  LOBBY SIGNAGE.   Tenant may, at its expense, install an identifying sign
     -------------
("Lobby Sign") on the walls in the ground floor elevator lobbies for both the
Low-Rise and Lower Mid-Rise (as to the Lower Mid-Rise, only after existing
signage is removed, which Landlord covenants will occur, no later than September
1, 2002) elevator banks of a size, design and in a  location approved by
Landlord, consistent with other lobby signage,  solely for Tenant's name and
logo to identify Tenant's occupancy in the Building.  Upon termination of the
Lease, Tenant shall, remove the Lobby Sign and restore the wall to its previous
condition.

40.  RIGHTS PERSONAL TO TENANT.  There are references in Section 4G and 47 of
     -------------------------
this Lease to rights being personal to Tenant or The Northern Trust Company.
Such references mean that those rights may not be assigned, granted or
transferred by The Northern Trust Company and may not be exercised by any
sublessee or assignee, other than an Affiliate to whom this Lease is assigned.
Wherever in this Lease it is provided that Tenant must Lease and occupy
prescribed square

                                       59
<PAGE>

footage or Rentable Area, these requirements may be satisfied by Tenant or any
assignee which is entitled to exercise such right.

41.  FIRST EXTENSION OPTION.  Subject to the provisions hereinafter set forth,
     ----------------------
Landlord hereby grants to Tenant an option to extend the Term of this lease on
the same terms, conditions and provisions as contained in this Lease, except as
otherwise provided herein, for one period of five (5) years (the "First
Extension Period") after the expiration of the Term, which First Extension
Period shall commence on January 1, 2021 ("First Extension Period Commencement
Date") and end on December 31, 2025.

     A.  Said option shall be exercisable by written notice from Tenant to
Landlord of Tenant's election to exercise said option given not later than the
date which is eighteen (18) months prior to the First Extension Period
Commencement Date.  If Tenant's option is not so exercised, then except as
otherwise provided in Paragraph D of this Section 41, said option shall
thereunder expire.

     B.  Tenant may only exercise said option, and an exercise thereof shall
only be effective, if at the time of Tenant's exercise of said option and on the
First Extension Period Commencement Date this Lease is in full force and effect
and Tenant is not in Default in payment of Rent or any other monetary obligation
under this Lease.

     C.  Rent per square foot of Rentable Area of the Premises payable during
the First Extension Period with respect to all space included in the Premises as
of the First Extension Period Commencement Date shall be equal to ninety five
percent (95%) of the Market Rental Rate (as hereinafter defined in Section 43).
Landlord shall give Tenant written notice of the Market Rental Rate and the Rent
for the First Extension Period within thirty (30) days following written request
by Tenant made not earlier than twenty four (24) months prior to the First
Extension Period Commencement Date.  If Tenant disagrees with Landlord's
determination, then Tenant shall notify Landlord as provided in Section 43C,
and such dispute shall be determined in accordance with the provisions of
Section 43C.

     D.  If for any reason other than Tenant's failure to timely request Market
Rental Rate or otherwise comply with provisions of this Section on a timely
basis, the arbitrators fail to arrive at a determination of Market Rental Rate
by a date which is 90 days prior to the date on which Tenant must elect to
exercise its option to extend the Term, then the date for Tenant's exercise of
its option and the Term shall be extended day for day by each day after such
90th day until such arbitrators' determination is made (but by not more than 90
days in the aggregate).  No such extension shall affect the date on which the
First Extension Period is to end.  Until determination of the Market Rental
Rate, Rent shall be payable for the limited extension period at a rate equal to
the greater of the last rate of Rent payable under the Lease and Tenant's
determination of Market Rental Rate.  Once Market Rental Rate is determined, if
different from the rate theretofore paid by Tenant, it shall be payable
retroactive to the expiration of the Term at the Market Rental Rate, and the
parties shall promptly refund or pay the excess or difference as necessary.  If
the option is exercised, the First Extension Period shall be deemed to have
commenced on the date stated in this Lease.

                                       60
<PAGE>

     E.  If Tenant has validly exercised said option, then once Rent has been
determined, Landlord and Tenant shall enter into a written supplement to this
lease confirming the Rent for the First Extension Period.

42.  SECOND EXTENSION OPTION.  Subject to the provisions hereinafter set forth,
     -----------------------
Landlord hereby grants to Tenant an option to extend the Term of this Lease on
the same terms, conditions and provisions as contained in this Lease, except as
otherwise provided herein, but only if Tenant has previously exercised or
concurrently exercises its option to extend the Term for the First Extension
Period, for one period of five (5) years (the "Second Extension Period") after
the expiration of the First Extension Period, which Second Extension Period
shall commence on January 1, 2026 (the "Second Extension Period Commencement
Date") and end on December 31, 2030.

     A.  Said option shall be exercisable by written notice from Tenant to
Landlord of Tenant's election to exercise said option given not later than the
date which is eighteen (18) months prior to the Second Extension Period
Commencement Date.  If Tenant's option is not so exercised, then, except as
otherwise provided in Paragraph D of this Section 42, said option shall
thereupon expire.

     B.  Tenant may only exercise said option, and an exercise thereof shall
only be effective, if at the time of Tenant's exercise of said option and on the
Second Extension Period Commencement Date this Lease is in full force and effect
and Tenant is not in Default in payment of Rent or any other monetary obligation
under this Lease.

     C.  Rent per square foot of Rentable Area of the Premises payable during
the Second Extension Period with respect to all space included in the Premises
as of the Second Extension Period Commencement Date shall be equal to ninety
five percent (95%) of the Market Rental Rate (as hereinafter defined in Section
43).  Landlord shall give Tenant written notice of the Market Rental Rate and
the Rent payable during the Second Extension Period within thirty (30) days
following written request by Tenant made not earlier than twenty one (21) months
prior to the Second Extension Period Commencement Date.  If Tenant disagrees
with Landlord's determination, then Tenant shall notify Landlord as provided in
Section 43C, and such dispute shall be determined in accordance with the
provisions of Section 43C.

     D.  If for any reason other than Tenant's failure to timely request Market
Rental Rate or otherwise comply with provisions of this Section on a timely
basis, the arbitrators fail to arrive at a determination of Market Rental Rate
by a date which is 90 days prior to the date on which Tenant must elect to
exercise its option to extend the Term, then the date for Tenant's exercise of
its option and the Term shall be extended day for day by each day after such
90th day until such arbitrators' determination is made (but by not more than 90
days in the aggregate).  No such extension shall affect the date on which the
Second Extension Period is to end.  Until determination of the Market Rental
Rate, Rent shall be payable for the limited extension period at a rate equal to
the greater of the last rate of Rent payable under the Lease and Tenant's
determination of Market Rental Rate.  Once Market Rental Rate is determined, if
different from the rate theretofore paid by Tenant, it shall be payable
retroactive to the expiration of the Term at the Market Rental Rate, and the
parties shall

                                       61
<PAGE>

promptly refund or pay the excess or difference as necessary. If the option is
exercised, the Second Extension Period shall be deemed to have commenced on the
date stated in this Lease.

     E.  If Tenant has validly exercised said option, then within thirty (30)
days after request by either party hereto, Landlord and Tenant shall enter into
a written amendment to this lease confirming the terms, conditions and
provisions applicable to the Second Extension Period as determined in accordance
herewith, with such revisions to the rental provisions of this lease as may be
necessary to conform such provisions to the new rental rate.

     F.  Tenant shall not have any option to extend the term of this lease
beyond the expiration of the Second Extension Period.

43.  MARKET RATE.   A. "Market Rental Rate" shall mean annual amount per
     -----------
rentable square foot and other rental charges for the portion of the term in
question equivalent to the period for which the Market Rental Rate is being
determined beginning the first (1st) day of the subject period that a willing,
credit-worthy, non-equity tenant leasing space comparable to the space to be
leased would pay and a willing landlord of an office building comparable to the
Building in the Chicago central business district office market (the "Market")
would accept at arm's length. Appropriate consideration will be given to base
net rent, rent escalations, tenant concessions (e.g. free rent, tenant
improvements and other cash allowances), length of term, size and location of
the premises being leased, tenant improvement allowances, brokerage commissions
and other generally applicable terms and conditions prevailing for comparable
space in comparable buildings located in the Market, as evidenced by then
recently completed renewals, or new leases or similar expansion leases (in the
event of an expansion option), within the Market.

     B.  Base Rent shall consist of a fixed annual rent reduced to a net per
square foot amount which represents rent minus the total rental concessions
provided by the Landlord. When this Lease provides that Rent per square foot of
Rentable Area is equal to a percentage of the Market Rental Rate, such
percentage shall be applied only against the fixed net rental component of
Market Rental Rate (before deductions of allowances and abatements), and not
against other components (such as Tenant's Proportionate Share of Operating
Expenses).

     C.  If Tenant disagrees with Landlord's determination of Market Rental Rate
(which Tenant must do, if at all, in writing setting forth Tenant's
determination of Market Rental Rate within seven (7) days after notice of
Landlord's determination of Market Rental Rate) and if the parties cannot agree
on the Market Rental Rate within ten (10) days thereafter, then such dispute
shall be determined by arbitration as hereinafter provided.  Landlord and Tenant
will each select an arbitrator within ten (10) days who shall be disinterested
and shall be a person that has been actively engaged in the development or
leasing of first-class office buildings in the downtown Chicago area or
otherwise knowledgeable about rental rates for a period not less than five (5)
years immediately preceding his or her appointment.  The arbitrators so
appointed shall appoint a third arbitrator within ten (10) days after
appointment of the initial two arbitrators.  If a party fails to select an
arbitrator or an arbitrator selected by a party fails to make a determination or
select a third arbitrator as required,

                                       62
<PAGE>

the Market Rental Rate determined by the other party shall be deemed the Market
Rental Rate. Landlord and Tenant shall each simultaneously submit to the
arbitrators a determination of Market Rental Rate. (If no submittal is made, the
parties shall be deemed to have submitted their original determinations.) The
arbitrators shall be directed to determine the Market Rental Rate within twenty
(20) days after the appointment of the third arbitrator; provided, however, that
in determining Market Rental Rate, the arbitrators shall select either
Landlord's estimate or Tenant's estimate of Market Rental Rate, and in no event
shall the arbitrators have the right (i) to average the Market Rental Rate
estimates submitted by Landlord or Tenant or (ii) to choose another number. The
decision of the arbitrators shall be in writing and in duplicating, one
counterpart thereof to be delivered to each of the parties who appointed them.
The arbitration shall be conducted in accordance with the rules of the American
Arbitration Association (or its successor) and applicable Illinois law, and a
decision of the majority of the arbitrators shall be binding, final and
conclusive on the parties. The fees of the arbitrators and the expenses incident
to the proceeding and the fees of respective counsel engaged by the parties and
the fees of expert witnesses and other witnesses called for by the parties shall
be paid by the losing party. If no determination is made prior to the date for
commencement of payment of rent for which Market Rental Rate must be determined,
then Landlord's determination shall be used until the arbitration is completed,
except as above provided. If a different Market Rental Rate is later determined,
Landlord shall refund any overpayments to Tenant or Tenant shall pay any excess
owed in each instance promptly.

44.  ELEVATOR TRANSFER. On or before December 31, 2001, Landlord will modify the
     -----------------
Lower Mid-Rise elevators (accessing floors 17 through 27) in the Building so
that each elevator will stop on the 16th floor as a transfer floor for Tenant,
all at Landlord's expense. If Landlord fails to do so, then Tenant shall have
the following remedies; If transfers at such floor cannot be made by January 1,
2002, as such date may be extended due to Landlord's failure or inability to
complete the work due to causes or delays beyond Landlord's reasonable control,
then Rent shall abate for the Premises then located on floors 17 through 27. If
the required transfers at such floor cannot be made by January 1, 2003, as such
date may be extended due to Landlord's failure or inability to complete the work
due to causes or delays beyond Landlord's reasonable control, then Rent shall
abate for the entire Premises. Any abatement provided for in this Section shall
continue only so long as all of such transfers cannot be made as required.
Tenant shall not have the right to terminate this Lease as a result of any
default by Landlord with respect to the work provided for in this Section. At
Landlord's request, Tenant shall confirm to Landlord that such transfer floor is
operational when such is the case.

45.  CONTRACTION OPTION.  Tenant shall have the right, exercisable by written
     ------------------
notice delivered to Landlord no later than fifteen (15) months prior to an
"Exclusion Date" shown below, to reduce the Premises in size by deleting one
full floor in the Building from the Premises as of the applicable Exclusion Date
("Contraction Option"), on the terms and conditions hereafter set forth.  In the
case of each exercise of a Contraction Option, the floor to be deleted from the
Premises ("Excluded Premises") shall be a full floor which is not contiguous to
any other full floor of the Premises or which is at the top or bottom of a
contiguous stack of full floors in the Lower Mid-Rise elevator banks (floors 17-
27, both inclusive).  Tenant's notice to Landlord shall identify the Excluded
Premises.  The Contraction Option  may be exercised up to three times.

                                       63
<PAGE>

--------------------------------------------------------------------------------
     A.  Exclusion Date                     Waived Expansion Option
         --------------                     -----------------------
--------------------------------------------------------------------------------
          July 1, 2007                      Second Expansion Option
--------------------------------------------------------------------------------
          July 1, 2011                      Third Expansion Option
--------------------------------------------------------------------------------
          July 1, 2015                      Fourth Expansion Option
--------------------------------------------------------------------------------

     B.  In the event that Tenant exercises a Contraction Option, the term of
this Lease shall terminate (except as otherwise provided herein) as to the
Excluded Premises as of the applicable Exclusion Date, as if the Lease had
expired by lapse of time, and the remainder of the Premises shall be the
Premises under this Lease ("Remainder Leased Premises").

     C.  Tenant shall vacate and deliver possession of the Excluded Premises to
Landlord on the Exclusion Date in the manner set forth in Lease for surrender of
the Premises.  Any retention of possession by Tenant of all or part of the
Excluded Premises after the Exclusion Date shall be deemed a holding over
without consent of Landlord, and shall be subject to the terms and conditions of
this Lease with respect to such retention of possession.

     D.  Effective as of the Exclusion Date, Rentable Area of the Premises, Base
Rent provided to be paid pursuant this Lease for the Excluded Premises and
Tenant's Proportionate Share, shall be reduced based upon the reduced square
footage of the Rentable Area of the Premises, as reasonably determined by
Landlord.

     E.  As a condition to the effective exercise of a Contraction Option,
Tenant shall pay Landlord a Contraction Fee (hereinafter defined), one-half of
which shall be paid on exercise of the Contraction Option and one-half  no later
than one (1) month before the Exclusion Date. The "Contraction Fee" means an
amount equal to Rent which would be payable for the twelve months following the
Exclusion Date, consisting of Base Rent, Tenant's Proportionate Share of
Operating Expenses (based on the last amounts estimated by Landlord and being
paid by Tenant and latest available tax bills, in the case of Taxes where not
paid by Tenant on the basis of estimates), Special Tenant Fee (based on amounts
last payable by Tenant for such component of Rent), and any other component of
Rent which is not a component of Rent as of Commencement Date but which payable
under the Lease.

     F.  Any notice of exercise of a Contraction Option shall be irrevocable by
Tenant once given.

     G.  Tenant represents and warrants to Landlord that the following will be
true as of the date Tenant exercises its Contraction Option, that there exist no
subleases affecting the Excluded Premises which are not simultaneously being
terminated by Tenant as of the Exclusion Date.

                                       64
<PAGE>

     H.  Tenant acknowledges that the Termination Fee constitutes a non-
refundable prepayment of rent, notwithstanding any subsequent leasing of the
Excluded Premises by Landlord.

     I.  Upon each exercise of a Contraction Option, Tenant thereby waives its
rights under Section 52 to lease as Expansion Space, the Expansion Space, the
Expansion Space Option identified in Section 45A opposite the applicable
Exclusion Date as a waived Expansion Option, and Landlord shall have no further
obligation to Tenant under Section 52 with respect to the identified herein as
the "Waived Expansion Option," Expansion Space.

46.  RIGHT OF FIRST OFFER UPON SALE OF THE BUILDING.
     ----------------------------------------------

     A.  Offering of the Real Estate for Sale.

         (i)   In the event that, at any time during the Term of this Lease,
Landlord intends to sell the Property, Landlord shall deliver written notice of
its intention ("Notice of Intent") to Tenant in advance of any such offering,
including a copy of any proposed offering memorandum relative to the Property,
and a then current operating statement and rent roll.

         (ii)  Further, if prior to delivery of a Notice of Intent, Landlord
receives an unsolicited offer to purchase the Property and is considering
selling the Property to the offeror (or others) as a result of having received
such an offer, Landlord shall so notify Tenant ("Notice of Offer") and, in
advance of accepting such offer and stating the principal terms of the offer.

         (iii) Tenant shall have a period of thirty (30) days following delivery
of the Notice of Intent or Notice of Offer to Tenant as the case may be within
which to advise Landlord by written notice ("Notice of Acceptance") that Tenant
is interesting in negotiating with Landlord for the purchase of the Property and
to negotiate and agree upon the basic terms of the purchase with Landlord in a
legally binding agreement ("Term Sheet").

         (iv)  If Tenant fails to deliver the Notice of Acceptance and execute a
Term Sheet within thirty (30) days following delivery of the Notice of Intent or
Notice of Offer, Tenant's rights shall terminate, and Landlord may offer the
Property for sale or accept any offer free of Tenant's rights under this Section
46.

     B.  The provisions set forth in this Section 46 shall not apply to a
proposed sale of the Property to any entity having a direct or indirect
ownership interest in Landlord, to a mortgagee of the Property having a
participating mortgage or similar right to share in profits derived from the
sale or refinancing of the Property (each such party being hereinafter referred
to as a "Participant"), to any entity controlled by, controlling or under common
control with any Participant, or to any sale or transfer between any of any
Participant, or any affiliates thereof."  Further, the rights of Tenant and
restrictions set forth in this Section 46 shall also not apply to any initial
sale or transfer of the Property, Building or Real Estate pursuant to a mortgage
foreclosure sale of any mortgage encumbering the Property, Building or Real
Estate or any deed given in lieu of foreclosure thereof,

                                       65
<PAGE>

but shall thereafter apply to any transfer by the purchaser who took title at
said mortgage foreclosure sale including the holder of said mortgage or its
nominee who took title by virtue of said mortgage foreclosure sale or deed in
lieu of foreclosure thereof.

     C.  At Landlord's request, following waiver, expiration or termination of
Tenant's rights under this Section, Tenant shall execute an instrument in
recordable form confirming termination of its rights under this Section 46.

     D.  Tenant acknowledges and agrees that notwithstanding the delivery of the
Notice of Intent or Notice of Offer by Landlord, the delivery of the Notice of
Acceptance by Tenant, or the execution and delivery of a purchase and sale
agreement with respect to the Property, rent due under this Lease with respect
to the Property shall continue to accrue and be payable until such time, if any,
as the closing of the sale of the Property occurs.

     E.  Tenant's rights under this Section 46 shall only apply so long as
Tenant or its Affiliates lease and occupy at least 25% of the Rentable Area of
the Building.

47.  NAME OF THE BUILDING.  As of the date of this Lease, Landlord does not
     --------------------
intend to change the name of the Building from "181 West Madison Building."
Landlord agrees not to hereafter grant to any Person the right to name the
Building for such Person (i.e., prominently identify the Building with a
particular name of such Person) by (a) installing prominent exterior signage at
the main entrance of the Building containing such other Person's name (other
than eyebrow signage for a ground floor retail tenant) and (b) referring to the
Building in marketing materials as the "XYZ" building" where "XYZ" is the name
of the other Person, without first offering to Tenant, on the same conditions,
the same rights to have the Building named for it. Further, Landlord agrees not
to grant to any Person the right to name the Building, if such Person does not
lease and occupy at least 25% of the Rentable Area of the Building. If Landlord
decides to offer such naming rights to Tenant, it shall give Tenant notice
thereof. If Tenant decides to exercise such rights, it shall do so by giving
Landlord notice thereof within fifteen (15) business days after Landlord's
notice of offer given to Tenant; if not exercised within said fifteen (15)
business day period, Tenant's rights under this Section 47 shall expire;
provided, however, if Landlord does not actually grant such rights to such
Person within one hundred eighty (180) days after expiration of Tenant's fifteen
(15) business day exercise period (or until consummation of the transaction
including the grant of such naming right, if longer), Tenant's rights shall
automatically be reinstated Tenant's right under this Section 47 to be offered
the rights to have the Building named for it, and any future naming right
granted to Tenant, is personal to The Northern Trust Company and to any
Affiliate to whom this Lease has been assigned and only applies at any time that
Tenant itself (or an Affiliate), occupies not less than 25% of the Rentable Area
of the Building; provided, however, if The Northern Trust Company has subleased
space to an Affiliate, it may designate the Affiliates, it may designate the
Affiliate's name to be used in lieu of The Northern Trust Company (or other new
name, as provided above).

                                       66
<PAGE>

     If Tenant ever leases and occupies fewer than the required number of square
feet of Rentable Area in the Building, Tenant's rights with respect to naming of
the Building shall thereupon expire and be without further force and effect.

     In the case of any change of name due to Tenant's change of name where
Building identification will be changed as described above, or a termination of
Tenant's rights to have the Building named for it, or Tenant's election not to
thereafter have the Building named for it, Tenant will pay all actual costs and
expenses of physically changing the identification of the Building and
replacement of all marketing materials using Tenant's name.

     If the Building is named for Tenant, then Tenant represents that it has the
right to use the name of the Tenant as the name of the Building.  Landlord has
no obligation to use any of the aforesaid names if prevented by injunction or
other court order or decree from using such names.

48.  PUT SPACE. Subject to the provisions hereinafter set forth, the space shown
     ---------
in the schedule below as "Put Space" shall be included in the Premises on a date
shown on the schedule set forth below (the "Put Space Commencement Date")
associated with such Put Space.

--------------------------------------------------------------------------------
 Put Space      Square Feet of    Put Space Commencement   Put Space Rent
 ---------      --------------    ----------------------   --------------
                Rentable Area     Date                     Commencement Date
                -------------     ----                     -----------------
--------------------------------------------------------------------------------
 25             21,804            9/1/2001                 2/1/2002
--------------------------------------------------------------------------------
 24 and 26      43,608            9/1/2002                 2/1/2003
--------------------------------------------------------------------------------

Landlord may, for any reason, one or more times and on not less than 120 days'
notice to Tenant prior to a Put Space Commencement Date, substitute any of the
following floors for any floor included in the Put Space shown in the schedule
above: 17, 18, 19, and 22.

     A.  Effective as of each Put Space Commencement Date, the applicable Put
Space shall be included in the Premises, subject to all of the terms, conditions
and provisions of this Lease, except that:

         (i)  the Base Rent per square foot of Rentable Area of the Put Space
              shall be $21.75, which shall commence on the applicable Put Space
              Rent Commencement Date, subject to increase during the First
              Extension Period and Second Extension Period as provided in this
              Lease;

         (ii) the Rentable Area of the Premises shall be increased by the
              Rentable Area of the Put Space;

                                       67
<PAGE>

          (iii)  the term of the demise covering the Put Space shall commence on
                 the Put Space Commencement Date and shall expire simultaneously
                 with the expiration or earlier termination of the Term of this
                 Lease, including any extension or renewal thereof;

          (iv)   the Put Space shall be rented in its "as is" condition as of
                 the Put Space Commencement Date; provided, however, Landlord
                 agrees to contribute an allowance to Tenant of up to $35.00 per
                 square foot of Rentable Area of each Put Space (the " Put Space
                 Allowance") to be used to reimburse Tenant for (1) costs of
                 improvements (both hard and soft) and (2) for other costs of
                 Tenant not to exceed $5.00 per square foot of Rentable Area of
                 the applicable Put Space. The Put Space Allowance shall be paid
                 in one lump sum payment by Landlord to Tenant within ten (10)
                 business days following Tenant's submission to Landlord of a
                 contract or contracts evidencing that the cost of the work
                 performed and which has not been reimbursed by Landlord equals
                 or exceeds the amount of the Put Space Allowance. As the work
                 in the Put Space progresses, Tenant shall require and collect,
                 and submit copies to Landlord of, general contractor's
                 statements, architect certificates (as to substantial
                 completion of the stages of the Put Space work as payments are
                 being made therefor) and partial and final lien waivers, as the
                 case may be, covering all work (including design costs) for
                 which the Put Space Allowance is being used to pay costs
                 thereof. Tenant shall be responsible for collecting and
                 submitting to Landlord the final lien waivers from all
                 contractors, subcontractors and materialmen involved in the
                 work.

          (v)    Tenant's Proportionate Share of Operating Expenses owed on
                 account of such Put Space for the Calculation Year in which the
                 Put Space Commencement Date occurs shall be prorated based on
                 that portion of the Calculation Year which falls on and after
                 the Put Space Rent Commencement Date.

          (vi)   After April 1, 2002, provided that the Put Space Rent
                 Commencement Date has occurred, Tenant shall pay Special Tenant
                 Fee, for the Put Space being included in the Premises.

     B.   Landlord shall deliver possession of the Put Space on the applicable
Put Space Commencement Date; provided however, if Landlord should be unable for
any reason to deliver possession of the Put Space on the Put Space Commencement
Date, Landlord shall not be subject to any liability for failure to deliver
possession, except as hereinafter provided.  Such failure to deliver possession
shall not affect either the validity of this lease or the obligations of either
Landlord or Tenant hereunder, or be construed to extend the expiration of the
Term of this lease either as to the Put Space or the balance of the Premises;
provided, however, that under such circumstances, (i) Landlord shall use good
faith efforts to deliver 120 days advance notice of the inability to deliver
possession on a timely basis, (ii) if the delay is not within Landlord's
reasonable control,  the Put

                                       68
<PAGE>

Space Commencement Date shall be delayed until possession is delivered, and the
Put Space Rent Commencement Date shall be delayed by the number of days that the
Put Space Commencement Date was delayed, (iii) if the delay is caused by
Landlord, the Put Space Commencement Date shall be delayed until possession is
delivered, and the Put Space Rent Commencement Date shall be delayed by two
times the number of days that the Put Space Commencement Date was delayed, (iv)
if the delay was caused by the existing tenant, then in addition to the delay
described in clause (ii) above, Tenant shall be entitled to receive from
Landlord any penalty which Landlord may receive from the existing tenant on
account of its retention of possession in the Put Space beyond the date provided
in its lease for surrender of possession. If possession of the Put Space is not
delivered within 24 months after the Put Space Commencement Date, Tenant may, by
notice to Landlord within ten (10) days thereafter (but prior to delivery of
such space) terminate its lease of such Put Space.

     C.  In the event any Put Space is leased to Tenant as First Offer Space,
Rent for the period prior to the Put Space Commencement Date shall be at the
Market Rental Rate for such space and determined only with reference to the
period prior to the Put Space Commencement Date.  After the Put Space
Commencement Date, Rent shall be payable at the rate applicable to Put Space,
and such space shall be deemed to be Put Space.

49.  ALLOWANCE FOR EXTENSION PREMISES. Landlord agrees to contribute an
     --------------------------------
allowance of up to $15.00 per square foot of Rentable Area of the Extension
Premises (the "Allowance") to reimburse Tenant for costs of improvements (both
hard and soft) previously made in the Premises and for which Landlord has not
previously reimbursed Tenant. The Allowance shall be paid in four installments,
the first three installments being in the amount of $4.00 per square foot of
Rentable Area, payable in the years 2003, 2004, and 2005, respectively, and the
fourth installment in the amount of $3.00 per square foot of Rentable Area of
the Extension Premises payable in 2006. Each installment shall be paid within
ten (10) business days following Tenant's request for payment, including
Tenant's submission to Landlord of a contract or contracts evidencing that the
cost of the work performed and which has not been reimbursed by Landlord equals
or exceeds the amount of the Allowance. As work progresses, Tenant shall require
and collect, and submit to Landlord copies of, general contractor's statements,
architect certificates (as to substantial completion of the work) and final lien
waivers, covering all work (including design costs) for which the Allowance is
being used to pay costs. Tenant shall be responsible for collecting and
submitting to Landlord the final lien waivers from all contractors,
subcontractors and materialmen involved in the work.

50.  TERMINATION OF EXISTING LEASE. Tenant is presently leasing and occupying
     -----------------------------
the Existing Premises under the Existing Lease. The Existing Lease shall
terminate on the Commencement Date of this Lease ("Existing Lease Termination
Date"), as if such date were the stated expiration date of the term of the
Existing Lease, including all options to lease additional space or purchase the
Real Estate shall terminate on the Existing Lease Termination Date; provided,
however, Tenant and Landlord shall not be released from liability under the
Existing Lease accruing prior to termination of such Existing Lease.

                                       69
<PAGE>

     A.  23/rd/ Floor.  The 23/rd/ Floor was included in the Premises under the
         ------------
Twelfth Amendment for a term ending March 31, 2005.  Pursuant to such Twelfth
Amendment, Landlord was obligated  to  contribute  certain sums toward work
being performed by Tenant on the 23/rd/ Floor. Landlord shall contribute (i) the
amounts required under the Twelfth Amendment (being $166,800.60) plus (ii) such
additional amounts (being $596,300) as are required to equal the total sum of
$763,140, less (iii) any amounts previously paid by Landlord under the Twelfth
Amendment, provided that Tenant complies with the conditions and requirements
set forth in Section 49 above necessary to receive an Allowance. The term of
lease of the 23/rd/ floor is hereby extended to be coterminous with the Term;
Base Rent for the 23/rd/ floor shall be payable at the applicable rate shown in
Exhibit H on and after the Commencement Date. Notwithstanding the date for
commencement of Rent for the 23/rd/ Floor under the Twelfth Amendment, Rent
shall commence on the date shown on Exhibit H.

     B.  36/th/ Floor.  The 36/th/ floor of the Building was leased to Tenant
         ------------
pursuant to the Ninth Amendment referred to in the Recitals and extended
pursuant to the Eleventh Amendment temporarily for a term expiring January 31,
2001 and, thereafter, on a month-to-month basis, subject to the parties' rights
hereinafter described.  The parties have previously agreed and hereby confirm
that the Lease for the 36/th/ floor will expire February 28, 2001, without any
                                                                           ---
further extension. The 36/th/ Floor is included in the Premises under this Lease
only to and including such expiration date. Commencing February 1, 2001, either
party shall have the right to terminate the Lease, as to the 36/th/ Floor space
only, effective as of the last day of a given month, by written notice given to
the other party no later than the first (1/st/) day of said month. If such
notice is not given by the first (1/st/) day of a month, then the term of lease
of the 36/th/ floor shall be extended at least until the last day of such month
on the terms of this Lease. If such notice is given, the Lease shall terminate,
as to the 36/th/ floor, as of the last day of the relevant month, Tenant shall
surrender the 36/th/ floor in accordance with the terms of the Lease regarding
surrender of space, and neither party shall have any further liability with
respect to the 36/th/ floor, except for liabilities arising prior to such
termination date. Rent for such space shall be payable as set forth on Exhibit
H. As of the expiration of the lease of the 36/th/ floor, Tenant's Proportionate
Share shall be reduced to reflect expiration of the lease of the 36/th/ floor.

     C.  Tenant represents and warrants to Landlord, with respect to Tenant's
right in and occupancy of the Existing  Premises, that the following are true as
of the date hereof and will be true on the Existing Lease Termination Date:

         (i)   Tenant owns and holds the entire interest of Tenant under the
               Existing Lease;

         (ii)  there exist no subleases affecting any of the Existing Premises;

         (iii) Tenant has not assigned or encumbered Tenant's interest under the
               Existing Lease or any part hereof; and

     D.  Unless the Commencement Date is January 1, 2001, then for the
Calculation Year in which the Commencement Date falls, (i) Tenant's
Proportionate Share of Operating Expenses shall

                                       70
<PAGE>

be payable without proration as provided in Section 4E, and (ii) Rent Adjustment
under Exhibit J shall be payable under this Lease without proration as provided
in Exhibit J and not as "Rent Adjustment" under the Existing Lease or prorated
under the Existing Lease.

51.  RIGHT OF FIRST OFFER TO LEASE. Provided that Tenant has not theretofore
     -----------------------------
leased such space, Tenant is not in Default under this Lease and this Lease is
in full force and effect from and after the Commencement Date, Tenant shall have
the option for and during the Term of this Lease, on and subject to the terms
and conditions hereinafter set forth, to lease all or any part of the space
which is located on floors 1 through 27, both inclusive, and floors 35 through
38, both inclusive, in the Building ("First Offer Space").

     A.  If, at any time and from time to time during the Term of this Lease, as
the same may be extended, any First Offer Space is or will be Available for
Lease (as hereinafter defined) then Landlord shall, before leasing such First
Offer Space, notify Tenant of the location and Rentable Area of First Offer
Space, a date for commencement of the term with respect to such portion of the
First Offer Space if leased by Tenant (the "First Offer Space Commencement
Date"), the term of lease of First Offer Space (if other than the balance of the
Term, as described in Section 51C below) and the Market Rental Rate for such
space as determined by Landlord for a term commencing on the First Offer Space
Commencement Date.   Landlord may use the form of notice set forth on Exhibit O
or a similar form provided such form contains all the information set forth in
Exhibit O.  The First Offer Space Commencement Date shall be no earlier than 120
days after the date of the First Offer Notice, and not later than fifteen (15)
months after the date of the First Offer Notice Tenant may not lease any
Expansion Space as First Offer Space when it would be also be available as
Expansion Space, unless Landlord otherwise agrees.

     B.  If Tenant disputes Landlord's determination of the Market Rental Rate
Tenant shall so notify Landlord as provided in Section 43 hereof and such
dispute shall be determined in accordance with the provisions of Section 43C
hereof.   Tenant shall have the right to lease all, but not less than all, the
First Offer Space described in the First Offer Notice.  Tenant's rights under
this Section 51 to lease First Offer Space shall not apply to any First Offer
Space whose First Offer Space Commencement Date would fall during the last year
of the Term, as extended.  Tenant may, within twenty (20) business days after
its receipt of the First Offer Space Notice, elect to exercise its option to
lease such First Offer Space Available for Lease included in the First Offer
Space Notice, as of the First Offer Space  Commencement Date and on the terms
set forth in the First Offer Space Notice or other terms agreed to by Tenant and
Landlord, or otherwise set forth in this Section.

     C.  First Offer Space shall be "Available for Lease" upon:

         (i) the expiration of one tenant's Building Lease (as hereinafter
     defined) of such portion of the First Offer Space, if such portion of the
     First Offer Space is not then subject to a right or option to lease such
     space granted in another Building Lease; or

                                       71
<PAGE>

          (ii)   if such portion of the First Offer Space is subject to a right
     or option granted in another Building Lease (whether or not theretofore
     exercised), but such First Offer Space shall be deemed Available for Lease
     only for a term which expires on the date possession would be required to
     be delivered to the tenant holding such option or right.

          (iii)  if such portion of the First Offer Space is subject to a right
     or option granted in another Building Lease, which right or option is not
     exercised, upon the later to occur of (1) the expiration of such right or
     option unexercised and (2) the expiration of the Building Lease; or

          (iv)   if such portion of the First Offer Space is subject to a right
     or option granted in another Building Lease, which option is exercised, the
     expiration of the term of such other Building Lease or any later date on
     which the term of the demise of such portion of the First Offer Space
     created by the exercise of such right or option (including any renewals or
     extensions thereof) expires; and

          (v)    the First Offer Space becoming vacant and there being no
     Building Leases for such space or legal rights to possession held by
     persons other than Landlord; or

          (vi)   circumstances described in Section 51E(iv).

     D.   The term "Building Lease" shall mean a lease of any space in the
Building in effect on the Commencement Date of this Lease is executed by
Landlord and Tenant, any lease in the Building created by exercise of an option
granted in a Building Lease, or any lease of space in the Building entered into
after Tenant failed to exercise its option to lease such space under this
Section.

     E.   If Tenant has validly exercised its option pursuant to this Section
51, then, effective as of the First Offer Space Commencement Date, provided that
this Lease is then in full force and effect, such First Offer Space which Tenant
has elected to lease shall be included in the Premises, subject to all the
agreements, terms and conditions of this lease, with the following exceptions
and modifications:

          (i)    the Rentable Area of the Premises shall be increased by the
     Rentable Area of First Offer Space which Tenant so leased during the term
     of lease of First Offer Space;

          (ii)   the term of the demise covering such First Offer Space shall
     commence on the First Offer Space Commencement Date for such First Offer
     Space, and shall expire  at the end of the Term, as extended, or such
     earlier date as provided in Section 51C above.

          (iii)  the First Offer Space shall be leased in its "as is" condition
     as of the First Offer Space Commencement Date, and Landlord shall have no
     obligation to improve such space for Tenant's occupancy, unless the Market
     Rental Rate includes as a component

                                       72
<PAGE>

     thereof tenant improvement, specific base building condition of space or
     any construction allowance. In such case, Landlord shall provide any
     improvements. In any such case, Landlord shall furnish to Tenant a
     construction allowance in lieu of providing any tenant improvement or
     specific base building condition, which allowance shall be paid in the
     manner set forth in Section 48A(iv) hereof (except for the dollar amount),
     or other terms agreed to by Landlord and Tenant.

               (a)  the Rent for the First Offer Space shall be the rent set
          forth in such First Offer Space Notice or as otherwise determined as
          set forth in this Section, or if Landlord and Tenant have agreed to
          other rent, then such other Rent agreed to by Landlord and Tenant.

               (b)  If Tenant does not timely exercise its option to lease any
          particular First Offer Space covered by a First Offer Space Notice,
          then, except as hereinafter set forth in Section 53E(iv),  Tenant
          shall not have the right to lease that particular First Offer Space
          under this Section 51 until and if it again becomes Available for
          Lease.

               (c)  Upon the valid exercise by Tenant of its option to lease any
          First Offer Space and determination of applicable Rent, at the request
          of either party hereto, Landlord and Tenant shall enter into a written
          supplement to this lease incorporating the terms, conditions and
          provisions applicable to the First Offer Space so leased as determined
          pursuant to this Section 51.

          (iv) If Tenant does not timely exercise its option to lease any
     particular First Offer Space, Landlord may lease such space to another
     prospective tenant; provided, however, that if Landlord offers to lease
     First Offer Space to such prospective tenant  (other than pursuant to an
     option to lease, such as right of first offer or expansion option) at a net
     effective rental rate (calculated on a "level pay" method as shown on
     Exhibit M) more than 15% below the net effective rental rate (calculated on
     a "level pay" method as shown on Exhibit M) evidenced in the First Offer
     Space Notice, then such space shall again be subject to the right to lease
     granted to Tenant pursuant to Section 51A, requiring delivery of a First
     Offer Space Notice.  An increase in the length of term beyond the Term or
     change in amounts being amortized through rent affecting calculation of the
     net effective rental rate shall not constitute a reduction in rent
     requiring delivery of a First Offer Space Notice and shall not be subject
     to Tenant's rights under this Section 51E (iv).

     F.   Landlord shall deliver possession of the First Offer Space on the
First Offer Space Commencement Date. If Landlord is unable to deliver possession
of the First Offer Space by the First Offer Space Commencement Date, Landlord
shall not be subject to any liability for failure to deliver possession except
as hereinafter provided. Any such failure to deliver possession shall not affect
either the validity of this Lease or the other obligations of either Landlord or
Tenant hereunder except as hereinafter provided, or be construed to extend the
expiration of the term of this Lease either as

                                       73
<PAGE>

to the First Offer Space or the balance of the Premises; provided, however, the
applicable First Offer Space Commencement Date shall be delayed until Landlord
is able to deliver possession. If the delay in delivery of possession is more
than 90 days, and if such delay is not caused by the existing tenant or for
other reasons outside Landlord's control as set forth in Section 35D, then
Tenant shall have all remedies at law and equity (except Tenant shall not have
any right to terminate this Lease). Further, if Landlord is unable for any
reason to deliver possession of the First Offer Space within one year after
First Offer Commencement Date, Tenant by notice to Landlord, may elect to cancel
its obligation to take the First Offer Space in question.

52.  EXPANSION SPACE. Subject to the provisions hereinafter set forth, Landlord
     ---------------
hereby grants to Tenant four separate options to lease, on the terms and
conditions hereinafter set forth, space ("Expansion Space") of a size and
location and on the dates as provided below.

     A.  The size and locations of Expansion Space and dates for commencement of
the lease of such Expansion Space ("Expansion Space Commencement Date") are
described in the chart below, which are identified serially as "First Expansion
Option", "Second Expansion Option", "Third Expansion Option" and "Fourth
Expansion Option", each of which may also be identified as an "Expansion
Option".

                               EXPANSION OPTIONS
                               -----------------

--------------------------------------------------------------------------------
                                         Rentable              Expansion Space
                      Expansion Space    Area                 Commencement Date
                      ---------------    ----                 -----------------
--------------------------------------------------------------------------------
First                 21/st/ Floor       11,876               November 1, 2005
Expansion Option
--------------------------------------------------------------------------------
Second                17/th/ Floor       21,227               February 1, 2008
Expansion Option
--------------------------------------------------------------------------------
Third                 18/th/ Floor       20,848               November 1, 2012
Expansion Option
--------------------------------------------------------------------------------
Fourth                17/th/, 19/th/     Rentable Area for    August 1, 2015
Expansion Option      or 22/nd/ floor,   such floor shown on
                      as selected by     Exhibit B
                      Landlord
--------------------------------------------------------------------------------

         (i) Expansion Space available under the First Expansion Option shall
     be located on the 21st floor, unless the existing tenant on the 21st floor
     exercises any option in its lease which would preclude the delivery of
     possession to Tenant on the required date, in which case Landlord shall
     select space on another floor in the Lower Mid-Rise, or if not available,
     for the balance of the Term by the required Expansion Space Commencement
     Date then in the Upper

                                       74
<PAGE>

     Mid-Rise, of approximately the same Rentable Area (plus or minus 15%) to
     substitute for the space on the 21st floor.

          (ii)   Expansion Space available under the Second Expansion Option
     shall be located on the 17/th/ floor, unless the existing tenant on the
     17/th/ floor exercises any option in its lease which would preclude the
     delivery of possession to Tenant on the required date, in which case
     Landlord shall select another floor (or if acceptable to Tenant, up to two
     areas on two other floors) in the Lower Mid-Rise aggregating approximately
     the same square footage as the 17/th/ floor, plus or minus 15%), or if not
     available for the balance of the Term by the required Expansion Space
     Commencement Date, then in the Upper Mid-Rise, of approximately the same
     aggregate Rentable Area as the 17/th/ floor (plus or minus 15%) to
     substitute for the space on the 17/th/ floor.

          (iii)  Landlord is not required to make any Expansion Space contiguous
     to any other portion of the Premises.

          (iv)   Landlord shall notify Tenant no later than thirteen (13) months
     in advance, of its selection of Expansion Space, if not set forth in this
     Lease.   If a floor in the Lower Mid-Rise has not been selected because it
     would not be available by the required Expansion Space Commencement Date
     ("Unavailable Floor") (but would otherwise be available for the balance of
     the Term), Landlord shall also notify Tenant of the date it would be
     available.  If Tenant is willing to delay the Expansion Space Commencement
     Date until the date such space is available then Tenant shall notify
     Landlord within thirty (30) days of its election to delay the Expansion
     Space Commencement Date to the date the Expansion Space would be available
     (but no such delay shall delay the time for exercise of the option under
     Section 52B) and the Unavailable Floor shall become the Expansion Space.

     B.   Tenant's option to lease  Expansion Space shall be exercisable by
written notice from Tenant to Landlord given not less than twelve (12) months
prior to the  Expansion Space Commencement Date for such space.  If Tenant's
option is not so exercised, said option shall thereupon terminate and Tenant
shall not thereafter have any right to lease any  Expansion Space pursuant to
that Expansion Option.

     C.   Tenant may not elect to lease less than all Expansion Space in an
Expansion Option.

     D.   Tenant may only exercise said option, and an exercise thereof shall
only be effective if, at the time of Tenant's exercise of said option and on the
Expansion Space Commencement Date, this Lease is in full force and effect and
Tenant is not in Default under this Lease.

     E.   Landlord shall give Tenant written notice of the rental rate for the
Expansion Space (determined as hereinafter provided) within thirty (30) days
after Tenant's request made no earlier than eighteen (18) months prior to the
applicable Expansion Space Commencement Date, but in no event later than sixteen
(16) months prior to the applicable Expansion Space Commencement Date.

                                       75
<PAGE>

If Tenant disagrees with Landlord's determination, then Tenant shall so notify
Landlord as provided in Section 43C , and such dispute shall be determined in
accordance with the provisions of Section 43C.   If for any reason other than
Tenant's failure to timely request Market Rental Rate or otherwise comply with
provisions of this Section on a timely basis, the arbitrators fail to arrive at
a determination of Market Rental Rate by a date which is 60 days prior to the
date on which Tenant must elect to exercise its option to Lease Expansion Space
then the date for Tenant's exercise of its option shall be extended day for day
by each day after such 60th day until such arbitrators' determination is made
(but not extended more than 60 days in the aggregate).  The Expansion Space
Commencement Date shall not be extended.

     F.   If Tenant has validly exercised its option to lease  Expansion Space,
then effective as of the  Expansion Space Commencement Date, the Expansion Space
which Tenant will Lease shall be included in the Premises, subject to all of the
terms, conditions and provisions of this lease, except that:

          (i)    Rent per square foot of Rentable Area shall be at the rate of
     95% of the Market Rental Rate and shall commence five (5) months after the
     applicable Expansion Space Commencement Date;

          (ii)   the Rentable Area of the Premises shall be increased by the
     Rentable Area of the  Expansion Space; and

          (iii)  the term of the demise covering the  Expansion Space shall
     commence on the  Expansion Space Commencement Date and shall expire
     simultaneously with the expiration or earlier termination of the Term of
     this Lease, as extended;

          (iv)   the Expansion Space shall be leased in its "as is" condition as
     of the  Expansion Space Commencement Date, and Landlord shall have no
     obligation to improve such space for Tenant's occupancy,  unless the Market
     Rental Rate includes as a component thereof tenant improvements, specific
     base building condition or any construction allowance, in which case
     Landlord shall furnish a construction allowance in lieu of providing any
     tenant improvement or specific base building condition, which allowance to
     Tenant shall be paid in the manner set forth in Section  48A(iv) (except
     for the dollar amount) hereof.

          (v)    As a material consideration for this Lease, Landlord shall
     deliver possession of the Expansion Space on the Expansion Space
     Commencement Date. In the event Landlord should be unable for any reason to
     deliver possession of Expansion Space on the applicable Expansion Space
     Commencement Date, Landlord shall not be subject to any liability for
     failure to deliver possession, except as hereinafter provided. Such failure
     to deliver possession shall not affect either the validity of this Lease or
     the obligations of either Landlord or Tenant hereunder, or be construed to
     extend the expiration of the term of this Lease either as to the Expansion
     Space or the balance of the Premises; provided, however, that (a) the
     applicable Expansion Space Commencement Date shall be delayed until
     Landlord is able to

                                       76
<PAGE>

     deliver possession, (b) if the delay is more than 90 days, Tenant shall
     have all remedies at law and equity (except Tenant shall not have any right
     to terminate this Lease), (c) if the delay was caused by the existing
     tenant, then Tenant shall be entitled to receive from Landlord any penalty
     which Landlord receives from the existing tenant on account of its
     retention of possession in the Expansion Space beyond the date provided in
     its lease for surrender of possession, and (d) if the delay is more than 24
     months, Tenant may, at its election, by notice to Landlord within ten (10)
     days thereafter (but no later than delivery of such space), elect to
     terminate its lease of the Expansion Space.

          (vi)   In the event any portion of Expansion Space consisting of
     floors 17, 18, 19, 21 or 22 is leased to Tenant other than pursuant to this
     Section or Section 48, such portion of Expansion Space shall thereupon be
     deleted from the specific Expansion Space and the total amount of Expansion
     Space (approximately 75,000) which Landlord is obligated to make available
     and which Tenant may lease under this Section.

53.  PARKING. During the Term, Tenant shall be entitled to have up to 13 cars
     -------
parked (by valet [with Tenant's consent] or self-parking, at Landlord's option)
in the garage in the lower level of the Building in the location shown on
Exhibit Q, during the hours of 6:00 a.m. to 7:00 p.m. on weekdays and 7:00 a.m.
to 2:00 p.m. on Saturdays, so long as Tenant pays the parking charges in effect
from time to time (at monthly rates, if monthly rates are then being charged),
for the entire Term, subject to the terms and conditions, including parking
rules and regulations, applicable from time to time to parking in the garage.
Tenant shall pay parking charges for all parking provided for hereunder, whether
or not Tenant does, in fact, utilize such parking, except if Landlord or the
garage operator fails to provide such parking. If at any time Tenant elects not
to have 13 cars parked in the garage at any time, unless Tenant is paying for
such parking while not used, Tenant shall thereafter lose its rights to parking
of those number of cars for which spaces were not continuously paid, except as
hereinafter provided. Tenant shall be entitled to regain its right to park a car
if (a) it notifies Landlord 60 days in advance that it no longer requires use of
the right to park such car after such 60 day period but may require it in the
future and (b) notifies Landlord at least 60 days in advance of the date it
again requires such parking right. If at any time (i) a lease of space in the
Building terminates, and the tenant was entitled to park a certain number of
cars in the Building's parking garage pursuant to the terms of lease of that
space, and (ii) Tenant leases the same space in the building and that lease
commences within one month of the termination of the other tenant's lease, then
Landlord shall offer to Tenant, in a written notice, the additional right to
park that number of cars in the parking garage. If Tenant elects to use any or
all of such parking rights, it shall notify Landlord within seven (7) business
days after service of Landlord's notice, in which case Tenant shall have the
right to park such additional cars in the parking garage on the terms set forth
in this Section. Tenant not have the right to park any additional cars for which
Tenant does not notify Landlord as set forth above. Tenant and Landlord may
request the other party to confirm from time to time the number of cars which
Tenant may park in the parking garage. Payments for parking shall be the
responsibility of Tenant; Tenant (and not Landlord) shall be responsible for
collecting payments from any employees whom it permits to park in the building.
Particular spaces will not be reserved for Tenant, unless Landlord otherwise
agrees. Tenant shall not park automobiles overnight in the garage. Landlord
shall not be liable to

                                       77
<PAGE>

Tenant in damages or otherwise under any circumstances for failure to provide
parking if at any time Landlord or the garage operator is legally restricted
from operating a parking garage or providing parking in the lower level of the
Building or otherwise unable to do so for reasons beyond its reasonable control,
and in no event shall Tenant have any right to terminate this lease due to
Landlord's failure to make parking available as required under this Section.

54.  BACK UP GENERATOR. Tenant has advised Landlord it may wish to install a
     -----------------
back up generator in the Building to service the Premises. Landlord needs more
information about the generator, such as the type of generator, use, size, and
location, in order to assess whether any space can be made available in the
Building to Tenant for lease and the associated rent Landlord would require.

55.  KITCHEN FACILITIES. Tenant agrees that any cafeteria or dining room
     ------------------
("Kitchen Facilities") shall be operated subject to the following restrictions
and conditions:

     A.  Tenant shall, at its sole cost and expense, provide the necessary
exhaust fans and systems, ductwork (but Landlord shall provide, at Tenant's
cost, base building vertical duct and roof fans) and venting to ensure that all
smoke, odors, vapors and steam are exhausted from the Kitchen Facilities.  Such
systems shall be installed so as to prevent the discharge of smoke, odors,
vapors and steam into the common areas of the Building or into spaces leased to
other tenants.

     B.  No exhaust vents, flues, pipes or other outlets shall be installed
through the walls, floor or ceiling of the Premises or through any portion of
the Building (including but, not limited to the exterior walls or the roof of
the Building) without the written consent of Landlord as to the location,
construction and appearance thereof. Landlord may require that Tenant's exhaust
system be connected to pipes, stacks, flues, vents or other facilities located
outside the Premises and intended for use by Tenant and other food preparation
facilities in the Building. In such event, Tenant shall provide the necessary
pipes, vents, ductwork and other facilities to connect Tenant's exhaust system
thereto.

     C.  Tenant's exhaust or venting systems shall include fire prevention and
extinguishment facilities or systems as may be reasonably required from time to
time in view of Tenant's methods and volume of cooking and other food and
beverage preparation. This shall be in addition to any sprinkler or other fire
protection facilities installed in the Premises.

     D.  Tenant shall regularly and adequately clean or provide for the cleaning
of all exhaust and venting systems serving the Premises. This cleaning shall
include decreasing of all hoods, fans, vents, pipes, flues, grease traps and
other areas of such systems subject to grease buildup. Tenant shall provide to
Landlord, upon demand, reasonable proof that Tenant is doing such cleaning and
decreasing or causing it to be done. In the event that Tenant shall refuse or
fail to clean and degrease such systems or to arrange for the cleaning and
decreasing of such systems, then Landlord may, after seven (7) days notice to
Tenant, arrange for the cleaning and decreasing thereof, and Tenant shall pay

                                       78
<PAGE>

the entire cost thereof plus a charge equal to ten percent (10%) of such cost as
an over-head and supervision fee.

     E.  Tenant shall, at its sole cost and expense, engage professional
exterminators to service the Kitchen Facilities, including but not limited to
all food preparation and, food storage areas, at such frequency and to the
extent necessary to keep the Kitchen Facilities and the Premises free of
insects, rodents, vermin and other pests and to prevent insects, rodents, vermin
and other pests from the Kitchen Facilities and the Premises infesting spaces
leased to other tenants or the common areas of the Building and the Land. Tenant
shall provide to Landlord, upon demand, reasonable proof that Tenant is causing
such exterminating to be regularly performed. In the event that Tenant shall
refuse or fail to have such exterminating regularly performed, then Landlord
may, after seven (7) days notice to Tenant, arrange for such work to be done,
and Tenant shall pay the entire cost thereof plus a charge equal to ten percent
(10%) of such cost as an overhead and supervision fee.

     F.  Tenant shall receive the delivery of all goods and merchandise to the
Kitchen Facilities and the removal of all merchandise, supplies, equipment,
garbage and waste from the Kitchen Facilities only by way of the loading dock,
freight elevators and service corridors.

     G.  Tenant shall, at its sole cost and expense, comply with local fire
safety and building code requirements and with Landlord's requirements relating
to sanitation, extermination and waste disposal.

     H.  Tenant shall, at its sole cost and expense, remove all kitchen waste
from the Premises and have all such waste taken away from the Building on a
nightly basis.

     IN WITNESS WHEREOF, this instrument has been duly executed by the parties
hereto, as of the date first above written.

LANDLORD:                                       TENANT:
--------                                        ------

LASALLE BANK NATIONAL ASSOCIATION, not          THE NORTHERN TRUST COMPANY,
individually but solely and only as             an Illinois banking corporation
Trustee aforesaid

By: /s/ David J. Lanciotti                    By: /s/ Wayne LaChance
   -----------------------------------            -----------------------------
  Its:  Vice President                          Its:  Vice President
      --------------------------------                -------------------------

                                       79
<PAGE>

                                   EXHIBIT A
                                   ---------

                               Plan of Premises
                               ----------------

     The Premises consist of that areas shown on the floor plans affixed
(excluding from the foregoing any, if any: elevator shafts; flues; stacks;
pipes; shafts; vertical and horizontal ducts; pillars; demising walls;
electrical boxes; firehose cabinets; telephone closets; janitorial closets;
mechanical closets; and stairways) together with the right to use in common with
all other occupants of the Building, their invitees and the Landlord, the common
areas of the Building consisting of corridors, elevators and lobby for ingress
and egress to the Premises, washrooms and similar common facilities for their
intended purposes), all subject to the terms and provisions of the Lease.

--------------------------------------------------------------------------------
              Floor(s) or Space                                 Rentable Area
--------------------------------------------------------------------------------
                      4                                            16,491
--------------------------------------------------------------------------------
                      5                                            17,202
--------------------------------------------------------------------------------
                      6                                            21,227
--------------------------------------------------------------------------------
                      7                                            21,227
--------------------------------------------------------------------------------
                      8                                            21,227
--------------------------------------------------------------------------------
                      9                                            21,227
--------------------------------------------------------------------------------
                      10                                           21,227
--------------------------------------------------------------------------------
                      11                                           21,227
--------------------------------------------------------------------------------
                      12                                           21,227
--------------------------------------------------------------------------------
                      14                                           21,227
--------------------------------------------------------------------------------
                  Suite 1500                                       12,982
--------------------------------------------------------------------------------
                  Suite 1550                                        8,245
--------------------------------------------------------------------------------
                  Suite 1600                                       15,952
--------------------------------------------------------------------------------
                      20                                           21,804
--------------------------------------------------------------------------------
                      23                                           21,804
--------------------------------------------------------------------------------
                      36                                           20,866
--------------------------------------------------------------------------------
                    Total                                         305,162
--------------------------------------------------------------------------------
               Total without 36                                   284,296
--------------------------------------------------------------------------------

                                      A-1
<PAGE>

                                   EXHIBIT B
                                   ---------

                                 Rentable Area
                                 -------------

                    38                   20,866 square feet
          -----------------------------------------------------
                    37                   20,866 square feet
          -----------------------------------------------------
                    36                   20,866 square feet
          -----------------------------------------------------
                    35                   20,866 square feet
          -----------------------------------------------------
                    34                   22,480 square feet
          -----------------------------------------------------
                    33                   22,480 square feet
          -----------------------------------------------------
                    32                   22,480 square feet
          -----------------------------------------------------
                    31                   22,480 square feet
          -----------------------------------------------------
                    30                   22,480 square feet
          -----------------------------------------------------
                    29                   21,453 square feet
          -----------------------------------------------------
                    28                   21,844 square feet
          -----------------------------------------------------
                    27                   21,844 square feet
          -----------------------------------------------------
                    26                   21,720 square feet
          -----------------------------------------------------
                    25                   21,804 square feet
          -----------------------------------------------------
                    24                   21,804 square feet
          -----------------------------------------------------
                    23                   21,804 square feet
          -----------------------------------------------------
                    22                   21,804 square feet
          -----------------------------------------------------
                    21                   21,804 square feet
          -----------------------------------------------------
                    20                   21,804 square feet
          -----------------------------------------------------
                    19                   21,645 square feet
          -----------------------------------------------------
                    18                   20,848 square feet
          -----------------------------------------------------
                    17                   21,227 square feet
          -----------------------------------------------------
                    16                   20,852 square feet
          -----------------------------------------------------
                    15                   21,227 square feet
          -----------------------------------------------------

                                      B-2
<PAGE>

                    14                   21,227 square feet
          -----------------------------------------------------
                    12                   21,227 square feet
          -----------------------------------------------------
                    11                   21,227 square feet
          -----------------------------------------------------
                    10                   21,227 square feet
          -----------------------------------------------------
                     9                   21,227 square feet
          -----------------------------------------------------
                     8                   21,227 square feet
          -----------------------------------------------------
                     7                   21,227 square feet
          -----------------------------------------------------
                     6                   21,227 square feet
          -----------------------------------------------------
                     5                   17,202 square feet
          -----------------------------------------------------
                     4                   16,491 square feet
          -----------------------------------------------------

                                      B-3
<PAGE>

                                   EXHIBIT C
                                   ---------

                             Rules and Regulations
                             ---------------------

                            181 WEST MADISON STREET

                               CHICAGO, ILLINOIS

     1.  Removal Permit.  Tenant shall list all furniture, equipment and similar
         --------------
articles Tenant desires to remove from the Premises or the Building and deliver
a copy to Landlord and procure a removal permit from the Rental Agent
authorizing Building employees to permit such articles to be removed.

     2.  Doors To Be Locked.  Before leaving the Premises unattended, Tenant
         ------------------
shall close and securely lock all doors and transoms and shut off all utilities
in the Premises.  Any damage resulting from failure to do so shall be paid by
Tenant.

     3.  Signs.  Except as provided in the Lease, Tenant shall not paint,
         -----
display, inscribe or affix any sign, trademark, picture, advertising, notice,
lettering or direction on any part of the outside or inside of the Building, or
on the Premises, except on the public hallway doors of the Premises, and then
only such name or names or matter and of such color, size, style, character and
material as shall be first approved by Landlord in writing.  Landlord reserves
the right to remove any other matter, without notice to Tenant and at the cost
and expense of Tenant.

     4.  Sound Devices.  Tenant shall not place any radio or television antenna
         -------------
on the roof or on or in any part of the inside or outside of the Building other
than the inside of the Premises, or operate or permit to be operated any musical
or sound producing instrument or device inside or outside the Premises which may
be heard outside the Premises, or operate any electrical device from which may
emanate electrical waves which may interfere with or impair radio or television
broadcasting or reception from or in the Building or elsewhere.

     5.  Cleanliness And Obstruction of Public Areas.  Tenant shall not place
         -------------------------------------------
anything or allow anything to be placed near the glass of any door, partition,
or window which may be unsightly from outside the Premises; or take or permit to
be taken in or out of other entrances of the Building, or take or permit on
other elevators, any item normally taken in or out through the trucking
concourse or service doors or in or on freight elevators; or, whether
temporarily, accidentally, or otherwise, allow anything to remain in, place or
store anything in, or obstruct in any way, any passageway, exit, stairway,
elevator, shipping platform, or truck concourse.  Tenant shall lend its full
cooperation to keep such areas free from all obstruction and in a clean and
sightly condition and move all supplies, furniture and equipment as soon as
received directly to the Premises and move all such items and waste, other than
waste customarily removed by employees of the Building, being taken from the
Premises, directly to the shipping platform at or about the time arranged for
removal therefrom.

                                      C-1
<PAGE>

     6.  Additional Locks.  Tenant shall not attach or permit to be attached
         ----------------
additional locks or similar devices to any door, transom or window; or change
existing locks or the mechanism thereof; or make or permit to be made any keys
for any door other than those provided by Landlord. (If more than two keys for
one lock are desired, Landlord will provide them upon payment therefor by
Tenant.)

     7.  Defacing Premises.  Except as provided in the Lease, Tenant shall not
         -----------------
do any painting or decorating in the Premises; or mark, paint, cut or drill
into, drive nails or screws into, or in any way deface any part of the Premises
or the Building, outside or inside, without the prior written consent of
Landlord. (If Tenant desires signal, communication, alarm or other utility or
service connections installed or changed, the same shall be made by and at the
expense of Tenant, with the approval and under direction of Landlord.)

     8.  Special Freight Elevator Service for Tenant.  Upon written application
         -------------------------------------------
by Tenant, and approval thereof by Landlord, Landlord shall furnish freight
elevator service for Tenant at times other than those times provided for in the
Lease at rates for such usage from time to time maintained in effect by
Landlord.

     9.  Emergency Procedures.  Tenant shall appoint a floor warden from
         --------------------
Tenant's organization who shall be responsible for educating Tenant's employees
in the proper fire evacuation procedures and the scheduling and conducting of at
least one (1) fire drill per year for Tenant's employees who normally occupy the
Tenant's Premises in the Building. The Tenant shall notify the Office of the
Building of the date and time of Tenant's scheduled fire evacuation drill.

                                      C-2
<PAGE>

                                   EXHIBIT D
                                   ---------

               Cleaning Specifications - 181 West Madison Street
               -------------------------------------------------

I.   GENERAL TENANT FLOORS

     A.   Daily Service
          -------------

          1.   Empty and damp wipe ashtrays and trash cans and dispose of at
               locations on loading dock.

          2.   Dust all horizontal surfaces, desks, chairs, files, telephones,
               picture frames, etc.

          3.   Damp wash and wipe dry all plastic or formica desk tops and glass
               furniture tops.

          4.   Clean and sanitize drinking fountains, follow with stainless
               steel cleaners.

          5.   Spot clean all windows and partition glass, including lobby
               doors, door frames, around light switches, private entrance
               glass, pictures, wall decorations and handrails.

          6.   Dust mop and spot clean all tiled areas.

          7.   Vacuum all carpeted areas and remove gum, tar, etc., adhering to
               the floor.

          8.   Clean restrooms (sinks, toilets, urinals, etc.) with germicides.
               Clean and polish all mirrors, chrome plumbing fixtures, etc.  All
               partitions and tiled walls to be spot cleaned.

          9.   Damp clean all directory signage and tenant name signs.

          10.  Report immediately any graffiti marks which cannot be removed.

          11.  Damp dust all telephones, as needed.

          12.  Wash waste receptacles, as needed.

          13.  Dust and wash wooden doors, as needed.

                                      D-1
<PAGE>

     B.  Services as Required at an Additional Cost to Tenant
         ----------------------------------------------------

         1.   Spot clean carpeted areas.

         2.   Wash window sills.

         3.   Shampoo carpets.

         4.   Dust walls and spot wash.

         5.   Dust ceilings and vinyl base.

II.  GENERAL BUILDING

     A.  Elevators
         ---------

         1.   Clean light lenses and replace burned out bulbs.

         2.   Spot clean walls.

         3.   Use paste wax or appropriate treatment on finished metal.

         4.   Clean edges, corners and tracks.

         5.   Vacuum carpet and remove gum, tar, etc. adhering to floors.

         6.   Shampoo carpet, as necessary.

         7.   As necessary, dust ceiling.

         8.   Damp clean elevator doors and call buttons.

     B.  Lobby
         -----

         1.   Machine scrub lobby floor using only Ivory Liquid soap with water

         2.   Clean all class entrance ways and side panels.

         3.   Empty all ash urns.

         4.  Spot clean marble walls, mailboxes, security desk, etc.

                                      D-2
<PAGE>

         5.  Dust all horizontal ledges.

         6.  Damp clean elevator doors and call buttons.

     C.  Day Crew - Services
         -------------------

         1.   Police and replenish supplies in all women's restrooms, to include
              sanitary supplies.

         2.   Vacuum all passenger elevators twice each day - once before lunch
              and once after.

         3.   Clean all ash urns twice each day.

         4.   Clean all glass entrance doors in main lobby.

         5.   Dust mop and/or damp mop all marble floors in main lobby once each
              day, as well as granite plaza area.

         6.   One utility man to clean service area, hallway and dock area.

         7.   Supply toilet tissue, soap and towels in mens' and ladies'
              restrooms.

         8.   There will be a constant surveillance of public areas to insure
              cleanliness.

     D.  Weekly Services
         ---------------

         Stairways
         ---------
              1.   Sweep from top to bottom using oil base sweeping compound.

              2.   Dust handrails and ledges.

              3.   Dust lights between floors.

              4.   Dust walls and spot wash.

         Tile Floors
         -----------
              1.   Damp mop all tile floors.

              2.   Machine buff all tile floors.

         Marble Floors
         -------------
              1.   Spray buff all public areas or as needed.

                                      D-3
<PAGE>

     E.   Monthly Services
          ----------------

          Marble Floors, Etc.
          -------------------
               1.   Repair all traffic lanes and other "high wear" areas of
                    marble floors.

               2.   Vacuum all louvers, ventilating grills and dust light
                    fixtures in restrooms.

               3.   Wash and polish walls, partitions and enamel surfaces from
                    trim to floor in restrooms.

               4.   Thoroughly dust ceilings.

     F.   Quarterly Services
          ------------------

               Ceramic Tile Floors, Etc.
               -------------------------
               1.   Strip and re-coat all tile floors.

               2.   Dust and wash lights.

               3.   Dust shelving in empty closets and dry mop/vacuum floors.

               4.   Dust all vertical surfaces such as: walls, partitions, door
                    bucks and other surfaces above shoulder height.

               5.   Damp dust all ceiling AC diffusers, wall grills, registers
                    and other ventilating louvers.

     G.   Annual Services
          ---------------

          General
          -------
               Wash down all restroom walls and partitions.

          Windows
          -------
               Clean all exterior windows minimum of three times per year.

                                      D-4
<PAGE>

                                   EXHIBIT E
                                   ---------

                       Tenant Lease Estoppel Certificate
                       ---------------------------------

LANDLORD:

TENANT:

TENANT TRADE NAME:

PREMISES:

AREA: __________________ Sq. Ft.

LEASE DATE:

     The undersigned Tenant, as the tenant under the above-referenced lease (as
amended, modified, supplemented, extended, renewed or assigned, as set forth in
Paragraph 1 below, the "Lease"), hereby ratifies the Lease and certifies to
Lender, as mortgagee of the building in which the Leased Premises are located
(the "Building"), as follows:

1.   The Lease is a valid lease and in full force and effect, and represents the
     entire agreement between Landlord and Tenant.  The Lease has (check one):

     ( ___ )  Not been amended, modified, supplemented, extended, renewed or
              assigned.

     ( ___ )  Not been amended, modified, supplemented, extended, renewed or
              assigned, except by the following agreements:

                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________

2.   The Lease provides for an initial term of ________________ years, _________
     months. The term of the Lease commenced (or is anticipated to commence) on
     _______________, 19___, and will end on _________, ______. Tenant is in
     full and complete possession of the Premises demised under the Lease and
     has commenced full occupancy and use of the Premises, such possession
     having been delivered by Landlord and having been accepted by Tenant.

                                      E-1
<PAGE>

3.   The Lease (check one):

     ( ___ )  Does not contain an option to extend or renew the term thereof, or
              for any additional term or terms.

     ( ___ )  Contains one or more options for _________ additional term(s) of
              ___________ year(s) and _____________ month(s) (each) at a rate to
              be determined as follows:

                         See Sections __ of the Lease

                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________

4.   The description above of the Premises and Area is accurate.

5.   The Lease provides for monthly Base Rent installments of $____________.
     Tenant has commenced payment of monthly installments of Rent in the amount
     of $________________.

6.   No advance rental or other payment has been made in connection with the
     Lease, except rental for the current month, there is no "free rent" or
     other concession under the remaining term of the Lease and the Rent has
     been paid to and including ______________________, 19___.

7.   A security deposit in the amount of $ ________________ is being held by
     Landlord, which amount is not subject to any set-off or reduction or to any
     increase for interest or other credit due to Tenant.

8.   To the knowledge of Tenant, all obligations and conditions under the Lease
     (including construction obligations) to be performed or satisfied to date
     by Landlord have been performed or satisfied.

9.   Landlord (to Tenant's knowledge) is not in default, nor is Tenant in
     Default of any of the terms and conditions of the Lease and no event to
     Tenant's knowledge has occurred which, with the giving of notice or mere
     passage of time, or both, would constitute an event of default thereunder.
     Tenant has no claims, demands or causes of action against Landlord arising
     out of the Lease or Tenant's occupancy of the Leased Premises.

                                      E-2
<PAGE>

10.  Tenant has received no rent concessions or other inducements to execute the
     Lease which have not been fulfilled, except as follows:

                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________

11.  The Lease contains no options for Tenant to terminate the Lease (except on
     Landlord's default) or to expand or contract the Leased Premises, or any
     rights of first refusal, except as follows:

12.  Tenant has not exercised (or given Landlord any notice of its intent to
     exercise) any option or right of first refusal set forth in Paragraph 11
     above, except as follows:

                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________
                      __________________________________________________________

13.  Landlord has not rebated, reduced or waived any amounts due from Tenant
     under the Lease, either orally or in writing, nor has Landlord provided
     financing for, made loans or advances to, or invested in the business of
     Tenant.

14.  There are no actions, voluntary or involuntary (to Tenant's knowledge),
     pending against the Tenant under the bankruptcy laws of the United States
     or any state thereof.

15.  Tenant has not used or disposed of and will not use or dispose of,
     hazardous materials at the Leased Premises in violation of any
     environmental law, rule, regulation or ordinance at any time applicable to
     the Building or the Premises.

16.  Tenant has dealt with no brokers other than Douglas Elliman-Beitler
     Management Corporation and _____________________________________________ in
     connection with the Lease.

17.  The address for notices to Tenant, as stated in the Lease, is correct.

18.  Tenant is presently using _______________ parking spaces in the Building.

19.  The person executing this estoppel certificate on behalf of Tenant is duly
     authorized to do so.

20.  Tenant understands and acknowledges that Lender is relying upon the
     representations herein made.

                                      E-3
<PAGE>

     IN WITNESS WHEREOF, the undersigned has executed this Tenant Lease Estoppel
Certificate as of the ____ day of ____________, 200_.

                                               TENANT:
                                               ------

                                               ________________________________,
                                               a_______________________________

                                               By:_____________________________

                                               Typed Name:_____________________
                                               Title:__________________________

                                               Date:___________________________

                                               ATTEST:

                                               ________________________________
                                               Typed Name:_____________________
                                               Title:__________________________

                                      E-4
<PAGE>

                                   EXHIBIT F
                                   ---------

                               Legal Description
                               -----------------

PARCEL 1:
---------

SUB-LOTS 9, 10, 11 AND 12 IN THE SUBDIVISION OF LOTS 1 AND 2 IN BLOCK 95 IN
SCHOOL SECTION ADDITION TO CHICAGO IN SECTION 16, TOWNSHIP 39 NORTH, RANGE 14
EAST OF THE THIRD PRINCIPAL MERIDIAN, TOGETHER WITH THOSE PARTS OF THE ALLEYS
(VACATED IN PART BY ORDINANCE OF THE CITY COUNCIL OF THE CITY OF CHICAGO ON
MARCH 27, 1905), LYING NORTH OF AND ADJOINING SAID SUB-LOT 9 AND EAST OF AND
ADJOINING SAID SUB-LOTS 9, 10, 11 AND 12 AND WHICH PARTS LIE SOUTH AND WEST OF
THE RESPECTIVE CENTERLINES, AND SAID CENTERLINES EXTENDED, ALSO THE NORTH HALF
OF THAT PART OF THE 18 FOOT ALLEY, LYING SOUTH OF AND ADJOINING SAID SUB-LOT 12,
AND SOUTH OF THAT PART OF THE ALLEY EAST OF AND ADJOINING SAID SUB-LOT 12, WHICH
LIES WEST OF THE CENTERLINE EXTENDED SOUTH, IN COOK COUNTY, ILLINOIS.

PARCEL 2:
---------

SUB-LOT 6 IN THE SUBDIVISION OF LOTS 1 AND 2 IN BLOCK 95 IN SCHOOL SECTION
ADDITION TO CHICAGO IN SECTION 16, TOWNSHIP 39 NORTH, RANGE 14 EAST OF THE THIRD
PRINCIPAL MERIDIAN, TOGETHER WITH THE NORTH HALF OF THAT PART OF THE 10 FOOT
ALLEY WHICH LIES SOUTH OF AND ADJOINING SAID SUB-LOT 6, IN COOK COUNTY,
ILLINOIS.

PARCEL 3:
---------

SUB-LOTS 2, 3, 4 AND 5 IN THE SUBDIVISION OF LOTS 1 AND 2 IN BLOCK 95 IN SCHOOL
SECTION ADDITION TO CHICAGO IN SECTION 16, TOWNSHIP 39 NORTH, RANGE 14 EAST OF
THE THIRD PRINCIPAL MERIDIAN, TOGETHER WITH THOSE PARTS OF THE ALLEYS, LYING
SOUTH OF AND ADJOINING SAID SUB-LOTS 3, 4 AND 5 AND WEST OF AND ADJOINING SAID
SUB-LOT 2, AND WHICH PARTS LIE NORTH AND EAST OF THE RESPECTIVE CENTERLINES AND
SAID CENTERLINES EXTENDED, ALSO THE NORTH HALF OF THAT PART OF THE 18 FOOT ALLEY
LYING SOUTH OF AND ADJOINING SAID SUB-LOT 2, AND SOUTH OF THAT PART OF THE ALLEY
WEST OF AND ADJOINING SAID SUB-LOT 2, WHICH LIES EAST OF THE CENTERLINE EXTENDED
SOUTH, IN COOK COUNTY, ILLINOIS.

                                      F-1
<PAGE>

PARCEL 4:
---------

SUB-LOT 1 IN THE SUBDIVISION OF LOTS 1 AND 2 IN BLOCK 95 IN SCHOOL SECTION
ADDITION TO CHICAGO IN SECTION 16, TOWNSHIP 39 NORTH, RANGE 14 EAST OF THE THIRD
PRINCIPAL MERIDIAN, TOGETHER WITH THE NORTH HALF OF THAT PART OF THE 18 FOOT
ALLEY WHICH LIES SOUTH OF AND ADJOINING SAID SUB-LOT 1, IN COOK COUNTY,
ILLINOIS.

PARCEL 5:
---------

SUB-LOTS 7 AND 8 IN THE SUBDIVISION OF LOTS 1 AND 2 IN BLOCK 95 IN SCHOOL
SECTION ADDITION TO CHICAGO IN SECTION 16, TOWNSHIP 39 NORTH, RANGE 14 EAST OF
THE THIRD PRINCIPAL MERIDIAN, TOGETHER WITH THE NORTH HALF OF THAT PART OF THE
10 FOOT ALLEY WHICH LIES SOUTH OF AND ADJOINING SAID SUB-LOTS 7 AND 8, IN COOK
COUNTY, ILLINOIS.

TOGETHER WITH ALL RIGHT, TITLE AND INTEREST, IF ANY, IN THE STREETS ABUTTING THE
PROPERTY COMMONLY KNOWN AS WEST MADISON STREET AND SOUTH WELLS STREET.

STREET ADDRESS:    181 West Madison Street, Chicago, Illinois

PIN: 17-16-203-004-0000; 17-16-203-002-0000; 17-16-203-003-0000;
     17-16-203-005-0000; 17-16-203-001-0000

                                      F-2
<PAGE>

                                   EXHIBIT G
                                   ---------

                           ["Intentionally Deleted"]

                                      G-1
<PAGE>

                                   EXHIBIT H
                                   ---------

                                   Base Rent
                                   ---------

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------
Definition     Suite/     Rentable     Base Rent        Period              Base            Period
 of Space      Floor        Area        per RSF                           Rent per
                          (Square                                           RSF
                           Feet)
---------------------------------------------------------------------------------------------------------
<S>            <C>        <C>          <C>           <C>                  <C>        <C>
Extension         400       16,491        $10.38     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension         500       17,202        $21.00     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension         600       21,227        $21.00     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension         700       21,227        $21.00     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension         800       21,227        $21.00     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension         900       21,227        $21.00     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1000       21,227        $25.50     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1100       21,227        $25.50     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1200       21,227        $25.50     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1400       21,227        $25.50     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1500       12,982        $25.50     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        1550        8,245        $10.50     11/1/00 - 3/14/01      21.75     4/1/05 - 12/31/2020
                                          $18.25     3/15/01 - 3/14/02
                                          $18.80     3/15/02 - 3/14/03
                                          $19.36     3/15/03 - 3/14/04
                                          $19.94     3/15/04 - 3/14/05

Extension        1600       15,952        $29.89     11/1/00 - 3/31/05      21.75     4/1/05 - 12/31/2020

Extension        2000       21,804        $21.00     11/1/00 - 4/30/01      21.75     4/1/05 - 12/31/2020
                                          $21.63      5/1/01 - 4/30/02
                                          $22.28      5/1/02 - 4/30/03
                                          $22.95      5/1/03 - 4/30/04
                                          $23.64      5/1/04 - 3/31/05

23rd Floor       2300       21,804        $21.75   1/1/01 - 12/31/2020

36th Floor       3600       20,866        $10.00               2/28/00
---------------------------------------------------------------------------------------------------------
</TABLE>

                                      H-1
<PAGE>

                                   EXHIBIT I
                                   ---------

                              Items to be Removed
                              -------------------

The following are items which Landlord may require Tenant to remove from the
Premises:

     -    Stairways

     -    Dumbwaiters or elevators

     -    Pneumatic systems

     -    Special fire suppression systems (except for existing [as of date of
          this Lease] telecom room on the 6th floor)

     -    Raised flooring system

     -    Hard finish flooring surfaces which modify slab

     -    Equipment or fixtures permanently attached to the Premises or building
          system  (except existing [as of date of this Lease] card-reader system
          and existing [as of date of this Lease] supplemental HVAC on 6th and
          7th Floor training areas)

     -    Any brick or block partitions constructed using mortar or other
          cementitious bonding materials.

     -    Vaults.

     -    Pedestrian bridge

     -    Items containing Hazardous Materials

                                      I-1
<PAGE>

                                   EXHIBIT J
                                  ----------

                          Payment of Rent Adjustment
                          --------------------------

     A.   Definitions.  For the purposes of this Exhibit, the following terms,
words or phrases shall have the following meanings and definitions.

          (i)    "Consumer Price Index" ("CPI") means the revised Consumer Price
     Index for Urban Wage Earners and Clerical Workers, Chicago, All Items,
     issued by the Bureau of Labor Statistics, United States Department of Labor
     (1982-84=100).  If the Bureau of Labor Statistics substantially revises the
     manner in which the CPI is determined, an adjustment shall be made in the
     revised index which would produce results equivalent, as nearly as
     possible, to those which would be obtained if the CPI had not been so
     revised.  If the 1982-84 average shall no longer be used as an index of
     100, such change shall constitute a substantial revision.  If the CPI
     becomes unavailable to the public because publication is discontinued, or
     otherwise, Landlord and Tenant shall agree to substitute therefor a
     comparable index based upon changes in the cost of living or purchasing
     power of the consumer dollar published by any other governmental agency or,
     if no such index is available, then a comparable index published by a major
     bank, other financial institution, university or recognized financial
     publication.  As used herein, the CPI "for" any calendar month means the
     CPI announced for such calendar month regardless of when the CPI for such
     calendar month is announced or published.

          (ii)   "Rent Adjustment Deposits" means one-twelfth (1/12th) of the
     amounts of the Rent Adjustments, if any, for the then current Lease Year as
     Landlord shall reasonably estimate from time to time and communicate in
     writing to Tenant (until such amount is determinable, and an appropriate
     adjustment shall then be made).

          (iii)  "Rent Adjustment Termination Date" means March 31, 2005.

          (iv)   "Adjusted Annual Base Rent" means Base Rent as adjusted by the
     Rent Adjustment made pursuant to this Exhibit J.

          (v)    "Incremental Rent Adjustment" means the portion of the Rent
     Adjustment for the Subject Lease Year which is in excess of the Rent
     Adjustment that was added to Base Rent the preceding Lease Year.

          (vi)   "Subject Lease Year" means the Lease Year for which Rent
     Adjustment is being calculated.

     B.   Tenant shall pay for each Lease Year, to and including the Rent
Adjustment Termination Date, the following amounts ("Rent Adjustment"):

                                      J-1
<PAGE>

          (i) an amount equal to $.90 per RSF plus thirty percent (30%) of the
     product of (a) the Base Rent for the Extension Premises (except the 4/th/
     floor and Suite 1600, Suite 1550 and the 20/th/ floor) plus $.90 per RSF,
     multiplied by (b) the percentage change (positive or negative) of the CPI
     for January of the Subject Lease Year over the CPI for the first full month
     of 1990 (being 126.50); provided, however, that for any Lease Year the
     Incremental Rent Adjustment shall not exceed three percent (3%) of the Base
     Rent for the Extension Premises (except the 4/th/ floor and Suite 1600,
     Suite 1550 and 20/th/ floor) for the immediately preceding Lease Year; and

          (ii)   with respect to Suite 1600, an amount equal to the product of
     $29.89 per RSF, multiplied by 35% of the percentage increase (if any) of
     the CPI for January of the Subject Lease Year over the CPI for the month of
     January, 1996 (being 149.70) (collectively "Rent Adjustment").

          Any abatement in Base Rent or Rent Adjustment provided by this Lease
     shall be applied to reduce the amount due and owing by Tenant after the
     amount of the Rent Adjustment for the Subject Year has been determined
     without regard to any past or present abatements.  Neither the calculation
     of the amount of any Rent Adjustment nor the calculation of any limit on
     the amount of the Rent Adjustment provided in this paragraph shall include
     consideration of abatements in any component of the calculation;

          No Rent Adjustment is payable for the 4/th/ floor, Suite 1550, the
     20/th/ floor or 23/rd/ floor or 36th floor.

          A sample calculation of Rent Adjustment (other than for Suite 1600) is
     shown on Exhibit J-1.

     C.   Rent Adjustment Deposit - So long as Tenant is obligated to pay Rent
Adjustment, Tenant agrees to pay to the Rental Agent on the first day of each
and every month during the Term of this Lease the Rent Adjustment Deposit.  The
Rent Adjustment Deposits shall be deposited against the Rent Adjustment due or
to become due for the Lease Year during which such deposits are required to be
made.  All Rent Adjustment Deposits may be commingled and need not be segregated
by the Landlord or the Landlord's Rental Agent, and may be held and utilized by
the Landlord without payment to the Tenant of interest or any sums for the use
of any of said deposits.  During the last Lease Year or during any partial Lease
Year during which this Lease terminates or Rent Adjustment obligation ends,
Landlord may include in Rent Adjustment Deposits its reasonable estimates of the
Rent Adjustment which may not finally be determined until after the expiration
or termination of this Lease.

     D.   Landlord's Statement - Payment of Rent Adjustment.  Not later than one
hundred twenty (120) days after the expiration of each Lease Year, the Landlord
shall cause to be furnished to the Tenant a statement showing the following:

                                      J-2
<PAGE>

          (i)    CPI for the Calculation Year.

          (ii)   CPI for January 1990 and January 1996, as applicable.

          (iii)  The amount of Rent Adjustment due Landlord for the Calculation
                 Year, less credit for Rent Adjustment Deposits both paid by the
                 Tenant in and allocable to the said Calculation Year.

          (iv)   The Rent Adjustment Deposit due monthly as aforesaid during the
     Lease Year next following the Calculation Year for which the statement is
     given (subject to revision as aforesaid), including the amount or revised
     amount for the months prior to the rendition of the statement.

     Within fifteen (15) business days after the receipt of such statement, the
Tenant shall pay to the Rental Agent the amount of Rent Adjustment to the
Landlord for the Calculation Year, as reflected in said statement and the amount
of the Rent Adjustment Deposit due for the months between the expiration of the
Calculation Year described in the statement to and including the month in which
the statement is furnished.  If such statement shall reflect an amount due from
the Landlord to the Tenant, the Landlord shall refund such amount to Tenant
within fifteen (15) business days after Tenant's receipt of such statement.

     E.   Allocation - Survival. If the Term ends or Rent Adjustment Termination
Date occurs on any day other than the last day of December, any Rent Adjustment
due Landlord or Tenant shall be prorated, and the Tenant shall pay such amount
within fifteen (15) business days after being billed or Landlord shall pay such
amount to Tenant within fifteen (15) business days after determining such
calculation, as the case may be. The Tenant's obligation and covenants to pay
the Rent Adjustment and the Rent Adjustment Deposits each and all independent of
every other covenant set forth in this Lease shall survive the expiration or
termination of this Lease.

     Rent Adjustment shall not be prorated for the Lease Year in which the
Commencement Date falls, it being intended that such rent be paid as if the
obligation to pay Rent Adjustment for such Lease Year under this Lease commenced
January 1 of such year.

                                      J-3
<PAGE>

                             Exhibit J-1
                Sample Calculation of Rent Adjustments

<TABLE>
<CAPTION>
                                                                                Year 1
                                                                      (of the Existing       Year 2         Year 3        Year 4
                                                                       ---------------       ------         ------        ------
                                                                                 Lease)
                                                                                 -----
<S>                                                                   <C>               <C>            <C>            <C>
    A      Annual Base Rent (amount used for example purposes only)      $ 4,000,000.00 $ 4,000,000.00 $ 4,000,000.00 $ 4,000,000.00

    B      Rent Adjustment (exhibit J Para B)                            $   200,000.00 $   180,000.00 $   180,000.00 $   180,000.00
                                                                         -----------------------------------------------------------
    C      Annual Base Rent + Rent Adjustment (Row A + Row B)            $ 4,200,000.00 $ 4,180,000.00 $ 4,180,000.00 $ 4,180,000.00

    D      Base Year CPI                                                          126.5          126.5          126.5          126.5

    E      Current Year CPI (assumed)                                                              135            150            160
                                                                                        --------------------------------------------
    F      Change in CPI (Row E-Row D)/Row D                                                     0.067          0.186          0.265

    G      Rent Adjustment (Base Year to Subject Year
           30% x C x F)                                                                 $    84,018.00 $   233,244.00 $   332,310.00

           Annual Rent Adjustment Calc.
    H      Incremental Rent Adjustments Subject Year G - Prior Year J                   $    84,018.00 $   149,226.00 $   120,371.46

    I      Annual Cap Amount (3% of Prior Year Adj. Annual Base Rent) (3% x
           Prior Year K)                                                                $   126,000.00 $   127,920.54 $   131,758.16

           Cap Application If H greater than I Cap Applies                                Cap Not Appl      Cap Appls  Cap Not Appls
                                                                                        --------------------------------------------

    J      Subject Lease Year Rent Adjustment If cap not Appl: G                        $    84,018.00 $   211,938.54 $   332,310.00
                          If cap Applies: I plus Previous Year J
                                                                         -----------------------------------------------------------
    K      Adjusted Annual Base Rent                A+B+J                $ 4,200,000.00 $ 4,264,018.00 $ 4,391,938.54 $ 4,512,310.00
                                                                         ===========================================================
</TABLE>

                                     J-1-1
<PAGE>

                                   EXHIBIT K
                                   ---------

                 Example of Calculation of Special Tenant Fee
                 --------------------------------------------

<TABLE>
<CAPTION>
                                                                                         4% of Prior     Tax and
                                                                                           Year Tax      Expense
                                     Annual                                                & Expense    Component         Annual
                      Tax and      Percentage         Tax and                               Amount      (Lesser of    Special Tenant
                      Expense       Increase        Expense Cap                          (Prior Year     Col D or          Fee
       Lease      Amount per RSF    (Note 1)         (Col. C)                            Col A x 4%)   Col C x 4%)    Amount per RSF
       Year          (Col. A)       (Col. B)    (Prior Year X 1.03)      Fiscal Year       (Col D)        Col. E         (Col. F)
------------------------------------------------------------------------------------------------------------------------------------
<S>               <C>              <C>          <C>                  <C>                 <C>           <C>            <C>
2000 base year        $16.43
2001                  $16.84         2.50%            $16.92
2002                  $17.35         3.00%            $17.43         4/1/2002-3/31/2003     $0.67         $0.67           $0.67
2003                  $17.90         3.20%            $17.95         4/1/2003-3/31/2004     $0.69         $0.69           $1.36
2004                  $18.98         6.00%            $18.49         4/1/2004-3/31/2005     $0.72         $0.72           $2.08
2005                  $18.25        -3.82%            $19.05         4/1/2005-3/31/2006     $0.76         $0.74           $2.82
2006                  $18.84         3.25%            $19.62         4/1/2006-3/31/2007     $0.73         $0.73           $3.55
2007                  $19.50         3.50%            $20.21         4/1/2007-3/31/2008     $0.75         $0.75           $4.30
                                                                     4/1/2008-3/31/2009     $0.78         $0.78           $5.08
</TABLE>

Note 1:           The annual % increases illustrated is not intended to be
                    indicative of the future year Tax and Expense Amount %
                    increase, but have been derived for purposes of this example
                    only

Note 2:           The year 2000 Tax and Expense amount of $16.43 represents an
                    estimate only

Note 3:           The Amount shown are per RSF. These amounts must be multiplied
                    by the RSF of the Premises.
RSF = Rentable Square Feet

                                      K-1
<PAGE>

                                   EXHIBIT L
                                   ---------

                                 Stacking Plan
                                 -------------

                        181 West Madison Stacking Plan
                        ------------------------------

                    Floor                 Net Rentable
                    -----                 ------------

                    49                    13,163
                    48                    13,163
                    47                    17,397
                    46                    17,397
                    45                    17,397
                    44                    17,397
                    43                    17,397
                    42                    20,466
                    41                    20,466
                    40                    20,505
                    39                    20,866
                    38                    20,866
                    37                    20,866
                    36                    20,866
                    35                    20,866
                    34                    22,480
                    33                    22,480
                    32                    22,480
                    31                    22,480
                    30                    22,480
                    29                    21,453
                    28                    21,844
                    27                    21,844
                    26                    21,804
                    25                    21,804
                    24                    21,804
                    23                    21,804
                    22                    21,804
                    21                    21,804
                    20                    21,804
                    19                    21,645
                    18                    20,848
                    17                    21,227

                                      L-1
<PAGE>

                    16                       20,852
                    15                       21,227
                    14                       21,227
                    12                       21,227
                    11                       21,227
                    10                       21,227
                    09                       21,227
                    08                       21,227
                    07                       21,227
                    06                       21,227
                    05                       17,202
                    04                       16,491
                                             ------
               Total Rentable Area           918,555 Square Feet

                                      L-2
<PAGE>

                                 EXHIBIT M
                                 ---------

                                 Level Pay
                                 ---------

     The Level Pay Equivalent (LPE) is derived by discounting all elements of a
transaction's contracted and actual costs and cash flow back to the initial
investment date, at a pre-determined interest factor (resulting in a Net Present
Value, or NPV). The NPV is then amortized over the contract lease term,
utilizing the same interest factor. The initial month of the lease (in which the
Landlord's cash costs are theoretically incurred, unless stated otherwise) is
referred to as Month Zero (as costs are typically incurred prior to receiving
revenue), and each Lease Year of revenue is depicted in twelfths to properly
account for timing of monthly receipts. Correspondingly, the interest rate is
calculated on a monthly basis. Rental abatements (if any) are shown as a
negative cash flow in the year they occur.

     An example of an LPE calculation for a hypothetical lease is on the
following spreadsheet titled Sample LPE Calculation. This sample is intended for
example purposes only, and should not be construed to represent any actual or
factual information.

                                      M-1
<PAGE>

                                   Exhibit M
                            Sample LPE Calculation
                         -----------------------------
<TABLE>
<CAPTION>
------------------------------------------------------------------------------
                      Sum of
         Sum of     Commission      Misc
        Base Rent, Construction   Expenses         Net
         % Escn,    and Lease      (Legal,      Total at
                                                                                ----------------------------------------------------
       Fixed Escn,  Assumption  Architectural  Beginning     NPV    LPE of               Lease Assumptions for Sample Calculation
 Month  and CPI      Expense         Etc.)      of Month     10%    NPV10%      ----------------------------------------------------
------------------------------------------------------------------------------
<S>       <C>        <C>          <C>           <C>       <C>      <C>          <C>                            <C>
   0      $0.00      ($20.00)     ($1.00)       ($21.00)                        Lease Term (Yrs)                    5  Years
   1      $2.08       $ 0.00       $0.00         $ 2.08                         Net Base Rent                  $25.00  PSF
   2      $2.08       $ 0.00       $0.00         $ 2.08                         Annual Esculation               3.00%  Per Year
   3      $2.08       $ 0.00       $0.00         $ 2.08                         Tenant Improvements            $14.75  PSF
   4      $2.08       $ 0.00       $0.00         $ 2.08                         Legal Expense                   $0.50  PSF
   5      $2.08       $ 0.00       $0.00         $ 2.08                         Architectural Exp.              $0.50  PSF
   6      $2.08       $ 0.00       $0.00         $ 2.08                         Commission                      $5.25  PSF
                                                                                                         ------------
   7      $2.08       $ 0.00       $0.00         $ 2.08                         Total Landlord Cost            $21.00  PSF
                                                                                ----------------------------------------------------
   8      $2.08       $ 0.00       $0.00         $ 2.08                                     Landlord Cash Flow Analysis
                                                                                ----------------------------------------------------
   9      $2.08       $ 0.00       $0.00         $ 2.08                         Total Landlord Cost          ($ 21.00) PSF
  10      $2.08       $ 0.00       $0.00         $ 2.08                         Net Escl. Rent Year 1         $ 25.00  PSF
  11      $2.08       $ 0.00       $0.00         $ 2.08                         Net Escl. Rent Year 2         $ 25.75  PSF
  12      $2.08       $ 0.00       $0.00         $ 2.08   $ 2.70   $ 2.85       Net Escl. Rent Year 3         $ 26.52  PSF
  13      $2.15       $ 0.00       $0.00         $ 2.15                         Net Escl. Rent Year 4         $ 27.32  PSF
  14      $2.15       $ 0.00       $0.00         $ 2.15                         Net Escl. Rent Year 5         $ 28.14  PSF
                                                                                                           ----------
  15      $2.15       $ 0.00       $0.00         $ 2.15                         Total Net Eff. Rent           $111.73  PSF
                                                                                ----------------------------------------------------
  16      $2.15       $ 0.00       $0.00         $ 2.15                                       Economic Analysis Summary
                                                                                ----------------------------------------------------
  17      $2.15       $ 0.00       $0.00         $ 2.15                         Return After            NPV @10%          LPE@ 10%
                                                                                                    --------------------------------
  18      $2.15       $ 0.00       $0.00         $ 2.15                         Lease Year One           $ 2.70            $ 2.85
  19      $2.15       $ 0.00       $0.00         $ 2.15                         Lease Year Two           $24.79            $13.73
  20      $2.15       $ 0.00       $0.00         $ 2.15                         Lease Year Three         $45.39            $17.58
  21      $2.15       $ 0.00       $0.00         $ 2.15                         Lease Year Four          $64.60            $19.66
  22      $2.16       $ 0.00       $0.00         $ 2.15                         Lease Year Five          $82.51            $21.04
  23      $2.15       $ 0.00       $0.00         $ 2.15                         ----------------------------------------------------
  24      $2.15       $ 0.00       $0.00         $ 2.15   $24.79   $13.73
  25      $2.21       $ 0.00       $0.00         $ 2.21
  26      $2.21       $ 0.00       $0.00         $ 2.21
  27      $2.21       $ 0.00       $0.00         $ 2.21
  28      $2.21       $ 0.00       $0.00         $ 2.21
  29      $2.21       $ 0.00       $0.00         $ 2.21
  30      $2.21       $ 0.00       $0.00         $ 2.21
  31      $2.21       $ 0.00       $0.00         $ 2.21
  32      $2.21       $ 0.00       $0.00         $ 2.21
  33      $2.21       $ 0.00       $0.00         $ 2.21
  34      $2.21       $ 0.00       $0.00         $ 2.21
  35      $2.21       $ 0.00       $0.00         $ 2.21
  36      $2.21       $ 0.00       $0.00         $ 2.21   $45.39   $17.58
  37      $2.28       $ 0.00       $0.00         $ 2.28
  38      $2.28       $ 0.00       $0.00         $ 2.28
  39      $2.28       $ 0.00       $0.00         $ 2.28
  40      $2.28       $ 0.00       $0.00         $ 2.28
  41      $2.28       $ 0.00       $0.00         $ 2.28
  42      $2.28       $ 0.00       $0.00         $ 2.28
  43      $2.28       $ 0.00       $0.00         $ 2.28
  44      $2.28       $ 0.00       $0.00         $ 2.28
  45      $2.28       $ 0.00       $0.00         $ 2.28
  46      $2.28       $ 0.00       $0.00         $ 2.28
  47      $2.28       $ 0.00       $0.00         $ 2.28
  48      $2.28       $ 0.00       $0.00         $ 2.28   $64.60   $19.66
  49      $2.34       $ 0.00       $0.00         $ 2.34
  50      $2.34       $ 0.00       $0.00         $ 2.34
  51      $2.34       $ 0.00       $0.00         $ 2.34
  52      $2.34       $ 0.00       $0.00         $ 2.34
  53      $2.34       $ 0.00       $0.00         $ 2.34
  54      $2.34       $ 0.00       $0.00         $ 2.34
  55      $2.34       $ 0.00       $0.00         $ 2.34
  56      $2.34       $    0       $0.00         $ 2.34
  57      $2.34       $ 0.00       $0.00         $ 2.34
  58      $2.34       $ 0.00       $0.00         $ 2.34
  59      $2.34       $ 0.00       $0.00         $ 2.34
  60      $2.34       $ 0.00       $0.00         $ 2.34   $82.51   $21.04
        -----------------------------------------------
TOTALS  $132.73      ($20.00)     ($1.00)       $11,173  NPV @ 10% LPE @ 10%
</TABLE>
<PAGE>

                                   EXHIBIT N
                                   ---------

  Short Form of Lease
  -------------------

                              SHORT FORM OF LEASE
                              -------------------

     This Short Form of Lease ("Short Form Lease") made as of the ________day of
__________________, 200__, by and between ____________, a _______ corporation
("Tenant"), and ____________________________________________________, a
_____________________________ company ("Landlord").

                                  WITNESSETH:

     1.  Premises.  Landlord hereby leases to Tenant, and Tenant leases from
         --------
Landlord that certain premises (the "Premises") identified on Exhibit A hereto
in the building located at 181 West Madison Street on a parcel of real property
("Real Property") lying, being and situate in Cook County, City of Chicago,
State of Illinois, which Real Property is particularly described on Exhibit B
attached hereto and made a part hereof, on the terms of the lease of the
Premises between Landlord and Tenant dated ________________.

THIS DOCUMENT PREPARED BY
AND AFTER RECORDING RETURN TO:

Sue Ann Fishbein                              Address of Property:
PIPER MARBURY RUDNICK & WOLFE                 181 West Madison Street
                                              -----------------------
203 North LaSalle Street                      Chicago, IL
                                              -----------------------
                                              _______________________
Suite 1800                                    PIN:
Chicago, IL 60601-1293

                                      N-1
<PAGE>

     2.  Term and Renewal Options. The term of the Lease is for ________________
         ------------------------
( ) years, commencing. Tenant shall have two successive five-year options to
extend the term, on the terms and conditions set forth in the Lease.

     3.  Right to Lease Additional Space.  Tenant shall have the rights to lease
         -------------------------------
additional space in the Building as are set forth in the Lease.

     4.  Right of First Offer to Purchase the Building.  Tenant shall have the
         ---------------------------------------------
right to purchase the Real Property on the terms set forth in the Lease.

     5.  Incorporation of Lease.  This Short Form Lease is for informational
         ----------------------
purposes only and nothing contained herein shall be deemed to in any way modify
or otherwise affect any of the terms and conditions of the Lease, the terms of
which are incorporated herein by reference. This instrument is merely a
shortened form of the Lease and is subject to all of the terms, provisions and
conditions of the Lease. In the event of any inconsistency between the terms of
the Lease and this instrument, the terms of the Lease shall prevail.

     6.  Binding Effect.  The rights and obligations set forth herein shall be
         --------------
binding upon and inure to the benefit of the parties hereto and their respective
heirs, personal representatives, successors and assigns.

                                      N-2
<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Short Form of Lease
as of the day and year first above written.

                                            LANDLORD:

                                            ____________________________________
                                            a(n)________________________________

                                            By:_________________________________
                                            Print Name:_________________________
                                            Print Title:________________________

                                            TENANT:
                                            ________________ a______ corporation
                                            ____________________________________

                                            By:_________________________________
                                            Print Name:_________________________
                                            Print Title:________________________

STATE OF____________)
                    ) SS:
COUNTY OF___________)

     I HEREBY CERTIFY that on this day before me, a Notary Public duly
authorized in the State and County named above to take acknowledgments,
personally appeared, ___________________, to me known to be the person described
as the _________________ of _________________, a ________, who signed the
foregoing instrument in such capacity, and acknowledged the execution thereof to
be his free act and deed as such person in such capacity for the uses and
purposes therein mentioned, and that the said instrument is the act and deed of
said _________________.

     WITNESS my hand and official seal in the State and County last aforesaid
this ____ day of ______________, 2000.

                                               _________________________________
                                               Notary Public
                                               State of_________________________
                                               My Commission expires: __________

                                      N-3
<PAGE>

STATE OF __________ )
                    ) SS:
COUNTY OF__________ )

I HEREBY CERTIFY that on this day before me, an officer duly authorized in the
state and county named above to take acknowledgments, personally appeared
______________ as Assistant Secretary of , a corporation, to me known to be the
person who signed the foregoing instrument as such officer and he acknowledged
that the execution thereof was his free act and deed as such officer for the use
and purposes therein expressed and that the instrument is the act and deed of
said corporation.

WITNESS my hand and official seal this _______ day of _____________, 2000 in the
county and state first above written.

                                             ___________________________________
                                             Notary Public
                                             State of___________________________
                                             My Commission expires:_____________

                                      N-4
<PAGE>

                                   EXHIBIT O
                                   ---------

                          Form of First Offer Notice
                          --------------------------

                             [LANDLORD LETTERHEAD]

                                                    [Date]
CERTIFIED MAIL, RETURN RECEIPT REQUESTED
----------------------------------------
[The Northern Trust Company
50 South LaSalle Street
Chicago, IL 60675
Attention: Vice President, Corporate Real Estate]

Re: Lease dated ____________, 2000, by and between LaSalle Bank National
Association, as successor trustee to American National Bank and Trust Company of
Chicago, not individually, but solely and only as Trustee under Trust Agreement
dated April 5, 1990, and known as Trust Number 1105513-07, as Landlord, and The
Northern Trust Company, an Illinois banking corporation, as Tenant.

Pursuant to Section 51 of the Lease, Landlord hereby notifies you that the First
Offer Space described below is Available for Lease at the rent and on the
commencement date set forth below.

Location:

Floor Plan:  ____ attached    ____ not attached

Rentable Area:

First Offer Space Commencement Date (possession date):

Date for commencement of rent, if other
than First Offer Space Commencement Date:

Market Rental Rate:

Term of lease of First Offer Space to expire _________, because a right or
option to lease such space granted in another Building Lease described in
Section 51C (ii) or (iii).

                                      O-1
<PAGE>

     Capitalized terms used in this letter have the meaning set forth in the
Lease.

Please respond within twenty (20) business days after receipt of this notice if
you elect to lease the First Offer Space.

Very truly yours,

[Landlord, or its agent]

______   Tenant hereby elects to lease the First Offer Space described above on
the terms of this First Offer Space Notice.

______   Tenant waives its right to lease First Offer Space described above on
the terms of this First Offer Space Notice, subject to reinstatement as provided
in Section 51(D)(iv).

[Name of Tenant]

By:   _________________________
      Name:____________________
      Title:___________________
Date: _________________________

cc:  The Northern Trust Company
     50 South LaSalle Street
     Chicago, IL 60675
     Attention: General Counsel

                                      O-2
<PAGE>

                                   EXHIBIT P
                                   ---------

                                Landlord's Work
                                ---------------

1)  Work of Landlord specifically set forth in Section 14.

2)  HVAC design specifications set forth in Section 7A.

3)  Landlord's obligations with respect to ADA set forth in Section 29B.

4)  Electrical design standards set forth in Section 10A.

                                      P-1
<PAGE>

                                   EXHIBIT Q
                                   ---------

                            Parking Space Location
                            ----------------------

                    (Map of Northern Trust Parking Spaces)

                                      Q-1<PAGE>

                                                       EXHIBIT NUMBER (10) (xiv)
                                                       TO 2000 FORM 10-K

                                 OFFICE LEASE

                                    BETWEEN

                METROPOLITAN LIFE INSURANCE COMPANY (LANDLORD)

                                      AND

                      THE NORTHERN TRUST COMPANY (TENANT)

                           DATED: December 29, 2000
                                           --
<PAGE>

                                         10 South LaSalle - Northern Trust Lease
                                                                      0300031.10

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                            Page
<S>                                                                         <C>
ARTICLE ONE - BASIC LEASE PROVISIONS.......................................    1
         1.01     BASIC LEASE PROVISIONS...................................    1
         1.02     ENUMERATION OF EXHIBITS..................................    2
         1.03     DEFINITIONS..............................................    3

ARTICLE TWO - PREMISES, TERM AND FAILURE TO GIVE POSSESSION................    8
         2.01     LEASE OF PREMISES........................................    8
         2.02     TERM: TERMINATION OF PRIOR LEASE.........................    8
         2.03     INTENTIONALLY OMITTED....................................    8
         2.04     AREA OF PREMISES.........................................    8
         2.05     CONDITION OF PREMISES....................................    9

ARTICLE THREE - RENT.......................................................    9

ARTICLE FOUR - RENT ADJUSTMENTS AND PAYMENTS...............................   10
         4.01     RENT ADJUSTMENTS.........................................   10
         4.02     STATEMENT OF LANDLORD....................................   11
         4.03     BOOKS AND RECORDS........................................   11
         4.04     PARTIAL OCCUPANCY........................................   12

ARTICLE FIVE - INTENTIONALLY OMITTED.......................................   13

ARTICLE SIX - SERVICES.....................................................   13
         6.01     LANDLORD'S GENERAL SERVICES..............................   13
         6.02     ELECTRICAL SERVICES......................................   14
         6.03     ADDITIONAL AND AFTER-HOUR SERVICES.......................   14
         6.04     PHONE SERVICES...........................................   15
         6.05     DELAYS IN FURNISHING SERVICES............................   15
         6.06     CHOICE OF SERVICE PROVIDER...............................   16

ARTICLE SEVEN - POSSESSION, USE AND CONDITION OF PREMISES..................   17
         7.01     POSSESSION AND USE OF PREMISES...........................   17
         7.02     LANDLORD ACCESS TO PREMISES, APPROVALS...................   19
         7.03     QUIET ENJOYMENT..........................................   20

ARTICLE EIGHT - MAINTENANCE................................................   20
         8.01     LANDLORD'S MAINTENANCE...................................   20
         8.02     TENANT'S MAINTENANCE.....................................   20

</TABLE>

                                       i
<PAGE>

<TABLE>
<S>                                                                          <C>
ARTICLE NINE - ALTERATIONS AND IMPROVEMENTS.................................  21
         9.01     TENANT'S ALTERATIONS......................................  21
         9.02     LIENS.....................................................  22

ARTICLE TEN - ASSIGNMENT AND SUBLETTING.....................................  23
         10.01    ASSIGNMENT AND SUBLETTING.................................  23
         10.02    RECAPTURE.................................................  25
         10.03    EXCESS RENT...............................................  25
         10.04    TENANT LIABILITY..........................................  26
         10.05    ASSUMPTION AND ATTORNMENT.................................  26

ARTICLE ELEVEN - DEFAULT AND REMEDIES.......................................  26
         11.01    EVENTS OF DEFAULT.........................................  26
         11.02    LANDLORD'S REMEDIES.......................................  27
         11.03    ATTORNEY'S FEES...........................................  28
         11.04    BANKRUPTCY................................................  29
         11.05    LANDLORD'S DEFAULT........................................  30

ARTICLE TWELVE - SURRENDER OF PREMISES......................................  30
         12.01    IN GENERAL................................................  30
         12.02    LANDLORD'S RIGHTS.........................................  31

ARTICLE THIRTEEN - HOLDING OVER.............................................  31

ARTICLE FOURTEEN - DAMAGE BY FIRE OR OTHER CASUALTY.........................  31
         14.01    SUBSTANTIAL UNTENANTABILITY...............................  31
         14.02    INSUBSTANTIAL UNTENANTABILITY.............................  32
         14.03    RENT ABATEMENT............................................  33

ARTICLE FIFTEEN - EMINENT DOMAIN............................................  33
         15.01    TAKING OF WHOLE OR SUBSTANTIAL PART.......................  33
         15.02    TAKING OF PART............................................  33
         15.03    COMPENSATION..............................................  34

ARTICLE SIXTEEN - INSURANCE.................................................  34
         16.01    TENANT'S INSURANCE........................................  34
         16.02    FORM OF POLICIES..........................................  35
         16.03    LANDLORD'S INSURANCE......................................  35
         16.04    WAIVER OF SUBROGATION.....................................  35
         16.05    NOTICE OF CASUALTY........................................  37
         16.06    SELF INSURANCE............................................  37
</TABLE>

                                      ii

<PAGE>

<TABLE>
<S>                                                                          <C>
ARTICLE SEVENTEEN - INTENTIONALLY OMITTED...................................  37

ARTICLE EIGHTEEN - RULES AND REGULATIONS....................................  38
         18.01    RULES.....................................................  38
         18.02    ENFORCEMENT...............................................  38

ARTICLE NINETEEN - LANDLORD'S RESERVED RIGHTS...............................  38

ARTICLE TWENTY - ESTOPPEL CERTIFICATE.......................................  39
         20.01    IN GENERAL................................................  39
         20.02    ENFORCEMENT...............................................  39

ARTICLE TWENTY-ONE - INTENTIONALLY OMITTED..................................  39

ARTICLE TWENTY-TWO - REAL ESTATE BROKERS....................................  40

ARTICLE TWENTY-THREE - MORTGAGEE PROTECTION.................................  40
         23.01    SUBORDINATION AND ATTORNMENT..............................  40
         23.02    MORTGAGEE PROTECTION......................................  41

ARTICLE TWENTY-FOUR - NOTICES...............................................  41

ARTICLE TWENTY-FIVE - RENEWAL OPTIONS.......................................  42

ARTICLE TWENTY-SIX - ARBITRATION............................................  46

ARTICLE TWENTY-SEVEN - EXPANSION OPTIONS....................................  47

ARTICLE TWENTY-EIGHT - RIGHT OF FIRST OFFER.................................  52

ARTICLE TWENTY-NINE - SUBORDINATE EXPANSION OPTION..........................  54

ARTICLE THIRTY - CONTRACTION OPTION.........................................  56

ARTICLE THIRTY-ONE - TERMINATION OPTION.....................................  58

ARTICLE THIRTY-TWO - SIGNAGE................................................  58

ARTICLE THIRTY-THREE - PERSONNEL BRIDGE.....................................  59
</TABLE>

                                      iii
<PAGE>

<TABLE>
<S>                                                                          <C>
ARTICLE THIRTY-FOUR - MISCELLANEOUS........................................   60
         34.01    LATE CHARGES.............................................   60
         34.02    WAIVER OF JURY TRIAL.....................................   60
         34.03    OPTION...................................................   60
         34.04    TENANT AUTHORITY.........................................   60
         34.05    ENTIRE AGREEMENT.........................................   60
         34.06    MODIFICATION OF LEASE FOR BENEFIT OF MORTGAGEE...........   60
         34.07    SATELLITE SYSTEM.........................................   61
         34.08    EXCULPATION..............................................   61
         34.09    ACCORD AND SATISFACTION..................................   61
         34.10    LANDLORD'S OBLIGATIONS ON SALE OF BUILDING...............   61
         34.11    BINDING EFFECT...........................................   61
         34.12    CAPTIONS.................................................   61
         34.13    APPLICABLE LAW...........................................   62
         34.14    ABANDONMENT..............................................   62
         34.15    LANDLORD'S RIGHT TO PERFORM TENANT'S DUTIES..............   62
         34.16    GENERATOR................................................   62
         34.17    RIDERS...................................................   63
</TABLE>

                                      iv
<PAGE>

                                 OFFICE LEASE

                                  ARTICLE ONE
                            BASIC LEASE PROVISIONS

1.01 BASIC LEASE PROVISIONS

In the event of any conflict between these Basic Lease Provisions and any other
Lease provision, such other Lease provision shall control.

(1)  Building and Address:

     CHASE PLAZA
     10 South LaSalle Street
     Chicago, Illinois 60603

(2)  Landlord and Address:

     METROPOLITAN LIFE INSURANCE COMPANY
     c/o CB Richard Ellis, Inc.
     10 South LaSalle Street, Suite 1301
     Chicago, Illinois 60603

(3)  Tenant and Current Address:

     THE NORTHERN TRUST COMPANY
     10 South LaSalle, Suite 400
     Chicago, Illinois 60603

(4)  Date of Lease: December 29, 2000

(5)  Lease Term: fifteen (15) years

(6)  Commencement Date: January 1, 2001

(7)  Expiration Date: December 31, 2015

(8)  Base Rent:

     Period                  Monthly      Annually
     ------                  -------      --------

     01/01/01 to 12/21/01    $263,465.46  $3,161,585.53
     01/01/02 to 12/31/02    $211,288.76  $2,535,465.08
     01/01/03 to 12/31/03    $217,743.61  $2,612,923.28
     01/01/04 to 12/31/04    $245,284.30  $2,943,411.60
     01/01/05 to 12/31/05    $251,739.15  $3,020,869.80

<PAGE>

     Period                  Monthly      Annually
     ------                  -------      --------

     01/01/06 to 12/31/06    $258,194.00  $3,098,328.00
     01/01/07 to 12/31/07    $264,648.85  $3,175,786.20
     01/01/08 to 12/31/08    $271,103.70  $3,253.244.40
     01/01/09 to 12/31/09    $277,558.55  $3,330,702.60
     01/01/10 to 12/31/10    $284,013.40  $3,408,160.80
     01/01/11 to 12/31/11    $290,468.25  $3,485,619.00
     01/01/12 to 12/31/12    $296,923.10  $3,563,077.20
     01/01/13 to 12/31/13    $303,377.95  $3,640,535.40
     01/01/14 to 12/31/14    $309,832.80  $3,717,993.60
     01/01/15 to 12/31/15    $316,287.65  $3,795,451.80

(9)  Rentable Area of the office portion of the Building: 715,785 square feet

(10) Rentable Area of the Initial Premises:  129,097 rentable square feet,
     consisting of:

     Floor(s)       Rentable Square Feet
     --------       --------------------

         4                20,006
         5                19,549
         6                20,040
         7                20,040
         8                20,722
         9                10,291
         10               10,104
         13                8,345

(11) Security Deposit: Not applicable

(12) Suite Number of the Premises: 400

(13) Tenant's Share: 18.0357%

(14) Tenant's Use of the Premises: General office use consistent with general
     office use in other first-class office buildings in downtown Chicago,
     Illinois.

1.02 ENUMERATION OF EXHIBITS

The exhibits set forth below and attached to this Lease are incorporated in this
Lease by this reference:

SCHEDULE ONE:  Controllable Operating Expenses
EXHIBIT A:     Plan of Premises
EXHIBIT B:     Workletter Agreement
EXHIBIT C:     Rules and Regulations

                                       2
<PAGE>

EXHIBIT D:     Cleaning Specifications
EXHIBIT E:     Heating, Ventilating and Air-Conditioning
EXHIBIT F:     Base Building Conditions
EXHIBIT G:     Major Categories for Operating Expenses
EXHIBIT H:     Categories for Removal
EXHIBIT I:     Satellite License

1.03 DEFINITIONS
For purposes hereof, the following terms shall have the following meanings:

(1)  Affiliate: Any corporation or other business entity which (i) is currently
     ---------
     owned or controlled by, owns or controls, or is under common ownership or
     control with Tenant, or (ii) is Tenant's successor through merger,
     reorganization or consolidation or (iii) acquires substantially all of the
     assets or the capital stock of Tenant.

(2)  Adjustment Year:  The calendar year or any portion thereof after the
     ---------------
     Commencement Date of this Lease for which a Rent Adjustment computation is
     being made.

(3)  Bridge:  The walkway connecting the Building with the building located at
     ------
     50 South LaSalle Street, Chicago, Illinois (the "Tenant Building") at the
     sixth floor level, for use by persons going to and from the Tenant Building
     and to and from the Premises.

(4)  Building:  The office building located at 10 South LaSalle Street, Chicago,
     --------
     Illinois  60603.

(5)  Commencement Date:  The date specified in Section 1.01(6) as the
     -----------------
     Commencement Date, unless changed by operation of Article Two.

(6)  Common Areas:  All areas of the Real Property made available by Landlord
     ------------
     from time to time for the general common use or benefit of the tenants of
     the Building, and their employees and invitees, or the public, as such
     areas currently exist and as they may be changed from time to time;
     provided, however, that Landlord shall not make any changes in the Common
     Area that would materially impair, restrict or diminish Tenant's access to
     the Premises.

(7)  Decoration:  Tenant Alterations which do not require a building permit and
     ----------
     which do not involve any of the structural elements of the Building, or any
     of the Building's systems, including, without limitation, its electrical,
     mechanical, plumbing and security and life/safety systems.

(8)  Default Rate:  Two percent (2%) above the rate then most recently announced
     ------------
     by Bank One as its corporate base lending rate, from time to time
     announced, but in no event higher than the maximum rate permitted by law.

(9)  Environmental Laws:  Any Law governing the use, storage, disposal or
     ------------------
     generation of any Hazardous Material, including without limitation, the
     Comprehensive Environmental

                                       3
<PAGE>

Response Compensation and Liability Act of 1980, as amended and the Resource
Conservation and Recovery Act of 1976, as amended.

(10) Expiration Date:  The date specified in Section 1.01(7).
     ---------------

(11) Force Majeure:  Any accident, casualty, act of God, war or civil commotion,
     -------------
     strike or labor troubles, or any cause whatsoever beyond the reasonable
     control of Landlord or Tenant, including, but not limited to, energy
     shortages or governmental preemption in connection with a national
     emergency, or by reason of government laws or any rule, order or regulation
     of any department or subdivision thereof or any governmental agency, or by
     reason of the conditions of supply and demand which have been or are
     affected by war or other emergency.

(12) Hazardous Material:  Such substances, material and wastes which are or
     ------------------
     become regulated under any Environmental Law; or which are classified as
     hazardous or toxic under any Environmental Law; and explosives and
     firearms, radioactive material, asbestos, and polychlorinated byphenyls.

(13) Indemnitees:  Collectively, Landlord, any Mortgagee or ground lessor of the
     -----------
     Property, the property manager and the leasing manager for the Property and
     their respective directors, officers, agents and employees.

(14) Initial Premises:  The space located in the Building described in Section
     ----------------
     1.01(10) and depicted on Exhibit A attached hereto.
                              ---------

(15) Land:  The parcels of real estate on which the Building is located.
     ----

(16) Laws:  All laws, ordinances, rules, regulations and other requirements
     ----
     adopted by any governmental body, or agency or department having
     jurisdiction over the Property, the Premises or Tenant's activities at the
     Premises and any covenants, conditions or restrictions of record which
     affect the Property.

(17) Lease:  This instrument and all exhibits and riders attached hereto, as may
     -----
     be amended from time to time.

(18) Lease Year:  The twelve month period beginning on the first day of the
     ----------
     first month following the Commencement Date (unless the Commencement Date
     is the first day of a calendar month in which case it is the 12 month
     period beginning on the Commencement Date), and each subsequent twelve
     month, or shorter, period until the Expiration Date.

(19) Monthly Base Rent:  The monthly rent specified in Section 1.01(8).
     -----------------

(20) Mortgagee:  Any holder of a mortgage, deed of trust or other security
     ---------
     instrument encumbering the Property.

                                       4
<PAGE>

(21) National Holidays:  Those federal or state holidays or such other days on
     -----------------
     which banks in the State of Illinois are required to be closed for
     business.

(22) Operating Expenses: All costs, expenses and disbursements of every kind and
     ------------------
     nature which Landlord shall pay or become obligated to pay in connection
     with the ownership, management, operation, maintenance, replacement and
     repair of the Property (including, without limitation, the amortized
     portion of any capital expenditure or improvement, together with interest
     thereon, and the costs of changing utility service providers). Operating
     Expenses shall not include, (i) painting, redecorating or other work which
     Landlord performs in tenant spaces for any other tenant of the Building
     other than painting, redecorating or other work which is standard for the
     Building and performed for tenants subsequent to their initial occupancy;
     (ii) costs of capital improvements to the Building (except for amortized
     portion of capital improvements installed for the purpose of reducing or
     controlling Operating Expenses or complying with applicable Laws); (iii)
     depreciation; (iv) interest and principal payments on loans (except for
     loans for capital improvements which Landlord is allowed to include in
     Operating Expenses as provided above); (v) ground rental payments; (vi)
     real estate brokerage and leasing commissions and expenses of procuring
     tenants, including lease concessions and lease take-over obligations; (vii)
     advertising and marketing expenses; (viii) costs of Landlord reimbursed by
     insurance proceeds, condemnation proceeds or in another manner; (ix)
     expenses incurred in negotiating leases of other tenants in the Building or
     enforcing lease obligations of other tenants in the Building; (x)
     Landlord's or Landlord's property manager's corporate general overhead or
     corporate general administrative expenses; (xi) any management or similar
     fee in excess of the greater of (a) 3.0% of the total gross revenues of the
     Property, or (b) the fees then customarily charged for building management
     for buildings of like class and character in the area; (xii) any costs or
     other sums paid to any person or entity related to or affiliated with
     Landlord to the extent that same exceeds the reasonable and customary cost
     thereof; (xiii) professional fees incurred in connection with the
     preparation of financial statements, tax returns and other documents and
     information for Landlord or its mortgagees, except for audits of operating
     expenses; (xiv) costs of paintings, sculptures or other art work; (xv) bad
     debt or rent loss reserves; (xvi) charitable contributions; (xvii) overtime
     utility charges for utilities benefiting other tenants; (xviii) costs of
     curing defects in construction; (ixx) costs relating to retail stores or to
     other specialty services such as health clubs, broadcasting facilities or
     cafeterias (xx) any compensation paid to clerks, attendants or other
     persons in commercial concessions operated by Landlord; (xxi) costs
     incurred in connection with upgrading the Building (but not the Premises as
     set forth in Section 7.01(c) hereof) to comply with the current
     interpretation of disability, life, fire and safety codes, ordinances,
     statues or Laws in effect prior to the Commencement Date (including,
     without limitation, ADA), including penalties or damages incurred due to
     such non-compliance; and (xxii) legal and other professional fees and
     expenses incurred in resolving any disputes with tenants and other
     occupants or enforcing lease obligations, including, without limitation,
     court costs. If any Operating Expense, though paid in one year, relates to
     more than one calendar year, at option of Landlord such expense may be
     proportionately allocated among such related calendar years.

                                       5
<PAGE>

(23) Owner's Representative: The individual who is an employee of Landlord and
     ----------------------
     is charged with the day-to-day responsibility for the Building and the
     management and operation thereof and is the designated person to whom all
     notices for the Building are to be forwarded, as well as the individual who
     is charged with acting as liaison between Landlord and the Building manager
     in connection with the Building.  The initial Owner's Representative shall
     be Katherine B. McCarthy.  If at any time and from time to time Landlord
     designates a successor to Katherine B. McCarthy, Landlord shall communicate
     the name of such successor to Tenant in writing by a notice to be delivered
     by Landlord to Tenant. In the event Landlord fails to communicate the name
     of the successor to Tenant, it shall not be deemed a default hereunder.
     Notwithstanding the above, upon Tenant's written request, Landlord shall
     communicate the name of such successor within three (3) business days or as
     soon as possible in the case of an emergency.

     In the event Landlord sells the Building to an entity unrelated to
     Metropolitan Life Insurance Company, a New York corporation, then Owner's
     Representative shall mean Landlord.

(24) Premises: The Initial Premises and any office space located in the
     --------
     Building which may be added to or subtracted from the Initial Premises in
     accordance with the terms and provisions of this Lease.

(25) Prior Lease:  That certain Office Lease dated July 8, 1987, as amended by
     -----------
     that certain First Amendment to Office Lease dated October 20, 1987; and by
     that certain Second Amendment to Office Lease dated January 16, 1998; and
     as further amended by that certain Third Amendment to Office Lease dated
     May 27, 1998 (collectively, the "Lease") for the lease of certain office
     space, currently consisting of the 4/th/ through 8/th/ floors and portions
     of the 9/th/, 10/th/ and 13/th/ floors in the Building.

(26) Property:  The Building, the Land, any other improvements located on the
     --------
     Land, including, without limitation, any parking structures and the
     personal property, fixtures, machinery, equipment, systems and apparatus
     located in or used in conjunction with any of the foregoing.

(27) Real Property:  The Property excluding any personal property.
     -------------

(28) Rent:  Collectively, Monthly Base Rent, Storage Space Rent, Rent
     ----
     Adjustments and Rent Adjustment Deposits, and all other charges, payments,
     late fees or other amounts required to be paid by Tenant under this Lease.

(29) Rentable Area of the Building:  The amount of square footage set forth in
     -----------------------------
     1.01(9).

(30) Rentable Area of the Initial Premises:  The amount of square footage set
     -------------------------------------
     forth in 1.01(10).

(31) Rent Adjustment:  Any amounts owed by Tenant for payment of Operating
     ---------------
     Expenses or Taxes. The Rent Adjustments shall be determined and paid as
     provided in Article Four.

                                       6
<PAGE>

(32) Rent Adjustment Deposit:  An amount equal to the Rent Adjustments
     -----------------------
     attributable to each month within the latest Adjustment Year for which the
     Rent Adjustment has been determined.  Landlord shall estimate the Rent
     Adjustment Deposit for the remainder of the first calendar year of this
     Lease based on the Taxes and Operating Expenses of the Property.

(33) Substantially Complete:  The completion of repair and/or restoration work
     ----------------------
     pursuant to Article Fourteen of this Lease or otherwise, except for minor
     insubstantial details of construction, decoration or mechanical adjustments
     which remain to be done and which do not interfere with Tenant's use of the
     Initial Premises for Tenant's business purpose and the completion of all
     work required by Landlord pursuant to the terms of this Lease, including
     those set forth on Exhibit F hereto with respect to the Premises.

(34) Taxes:  All federal, state and local governmental taxes, assessments and
     -----
     charges of every kind or nature, whether general, special, ordinary or
     extraordinary, which Landlord shall pay or become obligated to pay because
     of or in connection with the ownership, leasing, management, control or
     operation of the Property or any of its components, or any personal
     property used in connection therewith, which shall also include any rental
     or similar taxes levied in lieu of or in addition to general real and/or
     personal property taxes. For purposes hereof, Taxes for any year shall be
     Taxes which are assessed or become a lien during such year, whether or not
     such taxes are billed and payable in a subsequent calendar year. There
     shall be included in Taxes for any year the amount of all fees, costs and
     expenses (including reasonable attorneys' fees) paid by Landlord during
     such year in seeking or obtaining any refund or reduction of Taxes. Taxes
     for any year shall be reduced by the net amount of any tax refund received
     by Landlord attributable to such year. If a special assessment payable in
     installments is levied against any part of the Property, Taxes for any year
     shall include only the installment of such assessment and any interest
     payable or paid during such year. Taxes shall not include any federal,
     state or local government inheritance, general income, gift or estate
     taxes, except that if a change occurs in the method of taxation resulting
     in whole or in part in the substitution of any such taxes or franchise or
     capital stock taxes, or any other assessment, for any Taxes as above
     defined, such substituted taxes or assessments shall be included in the
     Taxes.

(35) Tenant Additions:  Collectively, Tenant Work and Tenant Alterations.
     ----------------

(36) Tenant Alterations:  Any alterations, improvements, additions,
     ------------------
     installations or construction in or to the Premises or any Building systems
     serving the Premises; and any supplementary air-conditioning systems
     installed by Landlord or by Tenant at Landlord's request pursuant to
     Section 6.01(b).

(37) Tenant Work:  The work specified in Section 2.05.
     -----------

(38) Tenant's Share:  The percentage specified in Section 1.01(13) which
     --------------
     represents the ratio of the Rentable Area of the Premises to the Rentable
     Area of the Building.

                                       7
<PAGE>

(39) Term:  The term of this Lease commencing on the Commencement Date and
     ----
     expiring on the Expiration Date.

(40) Termination Date:  The Expiration Date or such earlier date as this Lease
     ----------------
     terminates or Tenant's right to possession of the Premises terminates.

(41) Workletter:  The terms and provisions regarding the manner of completion of
     ----------
     Tenant Work attached as Exhibit B attached hereto.
                             ---------

                                  ARTICLE TWO
                 PREMISES, TERM AND FAILURE TO GIVE POSSESSION

2.01 LEASE OF PREMISES

Landlord hereby leases to Tenant and Tenant hereby leases from Landlord the
Premises for the Term and upon the terms, covenants and conditions provided in
this Lease.  In the event Landlord delivers possession of the Premises to Tenant
prior to the Commencement Date, Tenant shall be subject to all of the terms,
covenants and conditions of this Lease (except with respect to the payment of
Rent) as of the date of such possession.

2.02 TERM: TERMINATION OF PRIOR LEASE

The Commencement Date shall be January 1, 2001 and Tenant is currently in
possession of the Initial Premises in accordance with the terms of the Prior
Lease.

     Commencing on the Commencement Date, the term of the Prior Lease shall
terminate and expire (the "Effective Date") as if such date were the stated
expiration date of the term of the Prior Lease; provided, however, Tenant and
Landlord shall not be released from any liability under the Prior Lease accruing
before the Effective Date.  Landlord and Tenant shall each fully comply with all
of their respective obligations under the Prior Lease through the Effective Date

2.03 INTENTIONALLY OMITTED

2.04 AREA OF PREMISES

Landlord and Tenant agree that for all purposes of this Lease the Rentable Area
of the Initial Premises and the Rentable Area of the Building as set forth in
Article One have been measured according to the 1990 BOMA standard and are
controlling, and are not subject to revision after the date of this Lease.  Any
space leased prior to December 31, 2001 in accordance with the provisions of
this Lease will use the same 1990 BOMA standard.  For any space leased on or
after January 1, 2002 pursuant to any provision or option contained in this
Lease, Landlord will measure such space consistent with the BOMA standard being
utilized within the Building at the time such space is added to the Premises.

                                       8
<PAGE>

2.05 CONDITION OF PREMISES

The Initial Premises are currently occupied by Tenant and have been accepted in
their AS IS condition and Landlord has no obligation to make any improvement to
the Initial Premises, provided however, that Landlord shall contribute an amount
(the "Contribution") equal to One Million Nine Hundred Thirty-Six Thousand Four
Hundred Fifty-Five and No/100 Dollars ($1,936,455.00)(based on $15.00 per
rentable square foot) to be applied to Tenant's completion of such improvements
and additions to the Initial Premises as Tenant deems desirable including all
construction improvements, architectural and engineering fees, third party
construction consultants, FF&E expenses, or teledata related costs (the "Tenant
Work").  The Contribution shall be distributed in accordance with the terms and
conditions set forth in Exhibit B or applied as a Rent Credit as hereinafter
                        ---------
provided.  Tenant shall complete the Work in accordance with the terms of this
Lease, including, without limitation, Exhibit B.  The Contribution shall be
                                      ---------
available for Tenant's use anytime from the date this Lease is fully executed by
both parties through June 30, 2002.  If the costs of completing the Tenant Work
exceeds the sum of  the Contribution, Tenant shall pay all such costs. All
requests for disbursements from the Contribution must be received no later than
October 31, 2001.  Any unused portion of the Contribution which is not disbursed
by December 31, 2001, as provided above, shall be applied against the next
installments of Rent due from Tenant (the "Rent Credit"). In the event that
Tenant fails to use all of the Contribution as set forth above, or apply it as
Rent Credit, on or before December 31, 2002, Landlord shall have no further
obligation to either disburse such remaining funds or to apply such remaining
funds as Rent Credit and any unused Contribution shall be retained by Landlord
for its own use.

     No agreement of Landlord to alter, remodel, decorate, clean or improve the
Initial Premises, the Premises or the Real Property and no representation
regarding the condition of the Initial Premises or the Premises or the Real
Property has been made by or on behalf of Landlord to Tenant, except as may be
specifically stated in this Lease (including, without limitation, Articles
Twenty-Seven and Twenty-Eight) or in the Workletter.

                                 ARTICLE THREE
                                     RENT

Tenant agrees to pay to Landlord at the office specified in Section 1.01(2), or
to such other persons, or at such other places designated by Landlord, without
any prior demand therefor in immediately available funds and without any
deduction or offset whatsoever (except as specifically provided for in this
Lease), Rent, including, without limitation, Monthly Base Rent and Rent
Adjustments in accordance with Article Four, during the Term. Monthly Base Rent
shall be paid monthly in advance on the first day of each month of the Term,
except that the first installment of Monthly Base Rent shall be paid by Tenant
to Landlord on the Commencement Date.  Monthly Base Rent shall be prorated for
partial months within the Term. Rent which remains unpaid five (5) days after
the due date shall bear interest at the Default Rate. Tenant's covenant to pay
Rent shall be independent of every other covenant in this Lease.

                                       9
<PAGE>

                                 ARTICLE FOUR
                         RENT ADJUSTMENTS AND PAYMENTS

4.01 RENT ADJUSTMENTS

     (a)  Tenant shall pay to Landlord Rent Adjustments during the Term as
follows:

          (i)  The Rent Adjustment Deposit representing Tenant's Share of
     Operating Expenses and Taxes attributable to any calendar year (or portion
     thereof) monthly during the Term with the payment of Monthly Base Rent
     except the first installment which shall be paid by Tenant to Landlord on
     the Commencement Date; and

          (ii) Any Rent Adjustments due in excess of the Rent Adjustment
     Deposits in accordance with Section 4.02.

     (b) Notwithstanding anything to the contrary contained herein, for the
initial five (5) years (January 1, 2001 through December 31, 2005) of this
Lease, solely for purposes of calculating Rent Adjustments, Controllable
Operating Expenses (as defined below) for the period from the Commencement Date
through December 31, 2005 shall not exceed a 6% cumulative, compounded annual
rate of the total actual Controllable Operating Expenses for the Building (the
"Cap Amount") for the entire calendar year 2000 ("Base Year").

     For purposes of this subparagraph (b), "Controllable Operating Expenses"
shall mean only those items of Operating Expenses where the cost or expense
thereof shall be within the reasonable ability of Landlord to control on a per
annum basis, from time to time, and shall not include the following items (i)
insurance, (ii) collectively bargained union wages, and (iii) electricity and
other utilities, as well as any other items where the cost or expense thereof is
beyond the reasonable ability of Landlord to control. Such limitation on
Controllable Operating Expenses shall apply only to Controllable Operating
Expenses and not to other items of Operating Expenses and shall not limit or
otherwise affect Tenant's obligations regarding the payment of any component of
Rent other than the Controllable Operating Expenses component of Rent
Adjustment.

     Notwithstanding any of the foregoing provisions of this subparagraph (b),
the 6% cap, cumulative, compounded annual rate for the initial five (5) years
means that if the Controllable Operating Expenses in the first year are less
than 6%, but they exceed such amount in the second year, Landlord can recapture
the amount up to the applicable Cap Amount ("Excess Costs") and in the further
event in any prior or subsequent calendar years the Controllable Operating
Expenses were less than the applicable Cap Amount ("Excess Savings"), Landlord
shall have the right to charge Tenant, in addition to the Rent Adjustment
otherwise due Landlord for the applicable calendar year, the Excess Costs up to
the amount of the Excess Savings.  Several samples of how this might work are
set forth in Schedule One attached hereto and made a part hereof.

     The limitation on Controllable Operating Expenses set forth in this
subparagraph (b) shall not be applicable during any time period other than as
set forth above.

                                       10
<PAGE>

4.02 STATEMENT OF LANDLORD

As soon as feasible (as determined by Landlord) after the expiration of each
calendar year of this Lease, Landlord will furnish Tenant a statement
("Landlord's Statement") prepared according to generally accepted accounting
principles consistently applied, and certified by Landlord's then regularly
employed independent certified public accountant (the "CPA") to have been
prepared in conformity with the terms and provisions of this Lease, and
containing a schedule substantially similar to that shown as Exhibit G.
                                                             ---------
Landlord's Statement shall also show the following:

          (i)   Operating Expenses and Taxes for the Adjustment Year;

          (ii)  The amount of Rent Adjustments due Landlord for the Adjustment
     Year, less credit for Rent Adjustment Deposits paid, if any; and

          (iii) The Rent Adjustment Deposit due monthly in the calendar year
     next following the Adjustment Year including the amount or revised amount
     due for months prior to the rendition of the statement.

Tenant shall pay to Landlord within thirty (30) days after receipt of such
statement any amounts for Rent Adjustments then due in accordance with
Landlord's Statement. Any amounts due from Landlord to Tenant pursuant to this
Section shall be credited to the Rent Adjustment Deposits next coming due, or
refunded to Tenant within thirty (30) days if the Term has already expired
provided Tenant is not then in Default. No interest or penalties shall accrue on
any amounts which Landlord is obligated to credit or refund to Tenant by reason
of this Section 4.02. Landlord's failure to deliver Landlord's Statement or in
computing the amount of the Rent Adjustments shall not constitute a waiver by
Landlord of its right to deliver such items nor constitute a release of Tenant's
obligations to pay such amounts. The Rent Adjustment Deposit shall be credited
against Rent Adjustments due for the applicable Adjustment Year. During the last
complete calendar year or during any partial calendar year in which the Lease
terminates, Landlord may include in the Rent Adjustment Deposit its estimate of
Rent Adjustments which may not be finally determined until after the termination
of this Lease. Tenant's obligation to pay Rent Adjustments survives the
expiration or termination of the Lease. Landlord's obligation to refund any
amounts due from Landlord to Tenant hereunder shall survive expiration or
termination of this Lease. Notwithstanding the foregoing, in no event shall the
sum of Monthly Base Rent and the Rent Adjustments be less than the Monthly Base
Rent payable.

4.03 BOOKS AND RECORDS

     (a)  Landlord shall maintain books and records showing Operating Expenses
and Taxes in accordance with sound accounting and management practices,
consistently applied. Tenant or its representative (which representative shall
be a certified public accountant licensed to do business in the state in which
the Property is located) shall have the right, for a period of ninety (90) days
following the date upon which Landlord's Statement is delivered to Tenant, to
examine the Landlord's books and records with respect to the items in the
foregoing statement of Operating Expenses and Taxes during normal business
hours, upon written notice, delivered at least three (3)

                                       11
<PAGE>

business days in advance. If Tenant does not object in writing to Landlord's
Statement within one hundred fifty (150) days of Tenant's receipt thereof,
specifying the nature of the item in dispute and the reasons therefor, then
Landlord's Statement shall be considered final and accepted by Tenant. Any
dispute raised by Tenant shall be submitted to and resolved by CPA. Any amount
due to the Landlord as shown on Landlord's Statement, whether or not disputed by
Tenant as provided herein shall be paid by Tenant when due as provided above,
without prejudice to any such written exception.

     (b)  In the event such audit discloses (i) errors made during the prior
calendar year which, when totaled, established that the sum overcharged to and
paid by Tenant exceeds four percent (4%) of the actual (as distinguished from
estimated) amount of Tenant's Share of Operating Expenses and Taxes, Tenant's
reasonable costs of the audit shall be paid by Landlord, or (ii) no errors or an
error which equals or is less than four percent (4%), Tenant's costs of the
audit shall be paid by Tenant. If the audit determines that any sums are due and
owing Tenant, such sums shall be credited to the Rent Adjustment Deposits next
coming due or refunded to Tenant within thirty (30) days if this Lease has been
terminated.

     (c)  Tenant acknowledges and agrees that it is a condition of Tenant's
right to conduct an audit pursuant to the foregoing, that Tenant and/or its
representative, prior to commencement of such audit, execute a confidentiality
agreement whereby Tenant and/or its representative agree to keep confidential
and not disclose to any other party ( other than Tenant's employees involved in
such audit, and other professionals directly involved in the audit or results
thereof) the results of any such audit or any action taken by Landlord in
response thereto, except if required to disclose such information as required by
applicable law or court order.

     (d)  In the event Landlord sells the Building to an entity unrelated to
Metropolitan Life Insurance Company, a New York corporation, then Section
4.03(d) hereof shall be replaced with the following:

          "The fees of the CPA with respect to such dispute shall be paid by
          Tenant, unless the total amount of the Operating Expense and Tax
          Adjustment as provided in Landlord's Statement exceeds the total
          amount of the finally determined Operating Expense and Tax Adjustment
          (the "Audited Differential") by more than $25,000 and less than 4%, in
          which event, Landlord will reimburse Tenant for its actual costs not
          to exceed $5,000. In the event the Audited Differential is over 4% the
          finally determined Operating Expense and Tax Adjustment, Landlord will
          reimburse Tenant for its actual costs."

4.04 PARTIAL OCCUPANCY

For purposes of determining Rent Adjustments for any Adjustment Year if the
Building is not fully rented during all or a portion of any year, Landlord may
make appropriate adjustments to the Operating Expenses for such Adjustment Year
employing sound accounting and management principles consistently applied, to
determine the amount of Operating Expenses that would have been paid or incurred
by Landlord had the Building been 95% occupied, and the amount so determined
shall be deemed to have been the amount of Operating Expenses for such
Adjustment

                                       12
<PAGE>

Year. In the event that the Real Property is not fully assessed for any year,
then Taxes shall be adjusted to an amount which would have been payable in such
year if the Real Property had been fully assessed. In the event any other tenant
in the building provides itself with a service which Landlord would supply under
the Lease without an additional or separate charge to Tenant, then Operating
Expenses shall be deemed to include the cost Landlord would have incurred had
Landlord provided such service to such other tenant. In no event shall Landlord
be entitled to collect more than 100% of the Operating Expenses and/or Taxes (as
the case may be) for any Adjustment Year.

                                 ARTICLE FIVE
                             INTENTIONALLY OMITTED

                                  ARTICLE SIX
                                   SERVICES

6.01 LANDLORD'S GENERAL SERVICES

     (a)  So long as the Lease is in full force and effect, Landlord shall
furnish the following services:

          (i)   heat and air-conditioning in the Premises, Monday through Friday
     from 8:00 A.M. to 6:00 P.M., Saturday, from 8:00 A.M. to 1:00 P.M.,
     excluding National Holidays, as necessary in Landlord's reasonable judgment
     for the comfortable occupancy of the Premises under normal business
     operations, subject to compliance with all applicable voluntary and
     mandatory regulations and laws.  The current   parameters for the HVAC
     system are set forth on Exhibit E attached hereto and are subject to change
                             ---------
     as required by Law;

          (ii)  cold water for use in drinking fountains and tempered and cold
     water for use in lavatories in common with other tenants from the regular
     supply of the Building;

          (iii) customary cleaning and janitorial services in the Premises
     Monday through Friday, excluding National Holidays, in accordance with the
     Cleaning Specifications attached hereto as Exhibit D;
                                                ---------

          (iv)  washing of the outside windows in the Premises weather
     permitting and washing of the inside windows, both at intervals determined
     by Landlord but in no event less than three (3) times per year for each;

          (v)   automatic passenger elevator service in common with other
     tenants of the Building and freight elevator service subject to reasonable
     scheduling by Landlord and payment of Landlord's standard charges;

          (vi)  security services consistent with Class A Properties in downtown
     Chicago, including, but not limited to 24 hour manned security in the lobby
     or such other security services as may be used by such Properties;

                                       13
<PAGE>

          (vii) use of dock berths with access from LaSalle and/or Wells
     Streets for deliveries during normal business hours;

     (b)  Wherever heat generating machines or equipment are used in the
Premises which affect temperature otherwise maintained by the air-conditioning
system, Landlord reserves the right to require Tenant to provide, install,
operate and maintain supplementary air-conditioning units in the Premises at
Tenant's sole cost and expense.

     (c)  Tenant shall pay Landlord at rates fixed by Landlord for all tenants
in the Building, charges for all water furnished to the Premises for other
purposes, including the expenses of installation of a water line, meter and
fixtures.

     (d)  If requested by Tenant and subject to available capacity, Landlord
agrees to provide condenser water to the Premises throughout the year.  The cost
of the condenser water and any metering and hookup costs shall be at Tenant's
expense and shall be at rates then fixed by Landlord for all tenants in the
Building.

6.02 ELECTRICAL SERVICES

     (a)  Landlord will provide electricity for the Premises for the Tenant's
lighting and general office use of 5.6 watts per usable square foot or 4.8 watts
per rentable square foot. The Building shall be serviced by a minimum of two (2)
separate electrical power feeds each served by a separate substation and with an
automatic throw-over switch. The Tenant's Premises will be separately metered
and the Tenant shall directly pay the public utility for all electricity use
pursuant to the paragraph.

     (b)  The electricity used during the performance of janitorial service or
the making of alterations or repairs in the Premises by Landlord shall be paid
by Tenant. Landlord reserves the right to provide electricity to Tenant and in
such event Tenant agrees to purchase electricity from Landlord at rates which
shall not exceed the reasonably competitive rates for such service charged to
tenants by other potential utility providers in downtown Chicago, Illinois for
space comparable in size to the space leased to Tenant. Tenant shall make no
alterations or additions to the electric equipment or systems without the prior
written consent of the Landlord in each instance.

     (c)  Tenant shall make all necessary arrangements with the utility provider
chosen by Landlord for furnishing, metering and paying for electricity furnished
by it to Tenant and consumed on the Premises. Landlord shall permit Landlord's
wire and conduits, to the extent available and safely capable, to be used for
such purposes.

6.03 ADDITIONAL AND AFTER-HOUR SERVICES

At Tenant's request, Landlord shall furnish additional quantities of any of the
services or utilities specified in Section 6.01, if Landlord can reasonably do
so, on the terms set forth herein. Tenant shall deliver to Landlord a written
request for such additional services or utilities prior to 2:00 P.M. on Monday
through Friday (except National Holidays) for service on those days, and prior
to 2:00 P.M. on the last business day prior to Saturday, Sunday or a National
Holiday. For services or

                                       14
<PAGE>

utilities requested by Tenant and furnished by Landlord, Tenant shall pay to
Landlord as a charge therefor Landlord's prevailing rates for such services and
utilities within thirty (30) days after receipt from Landlord of an invoice for
such services. If Tenant shall fail to make any such payment within sixty (60)
days of the date when due, Landlord may, upon notice to Tenant and in addition
to Landlord's other remedies under this Lease, discontinue any or all of such
additional services.

6.04 PHONE SERVICES

All new telegraph, telephone, and electric connections or modifications to
existing systems which Tenant may desire shall be first approved by Landlord in
writing, before the same are installed, and the location of all wires and the
work in connection therewith shall be subject to the direction of Landlord.
Landlord reserves the right to restrict and control access to telephone
cabinets. Tenant shall be responsible for and shall pay all costs incurred in
connection with the installation of telephone cables and related wiring in the
Premises, including, without limitation, any hook-up, access and maintenance
fees related to the installation of such wires and cables in the Premises and
the commencement of service therein, and the maintenance thereafter of such wire
and cables; and there shall be included in Operating Expenses for the Building
all installation, hook-up or maintenance costs incurred by Landlord in
connection with telephone cables and related wiring in the Building which are
not allocable to any individual users of such service but are allocable to the
Building generally. If Tenant fails to maintain all telephone cables and related
wiring in the Premises and such failure affects or interferes with the operation
or maintenance of any other telephone cables or related wiring in the Building,
Landlord or any vendor hired by Landlord may enter into and upon the Premises in
accordance with the provisions of Section 7.02 and perform such repairs,
restorations or alterations as Landlord deems reasonably necessary in order to
eliminate any such interference (and Landlord may recover from Tenant all of
Landlord's reasonable costs in connection therewith). Tenant agrees that neither
Landlord nor any of its agents or employees shall be liable to Tenant, or any of
Tenant's employees, agents, customers or invitees or anyone claiming through, by
or under Tenant, for any damages, injuries, losses, expenses, claims or causes
of action because of any interruption, diminution, delay or discontinuance at
any time for any reason in the furnishing of any telephone service to the
Premises and the Building unless caused by the negligent acts or omissions or
willful misconduct of Landlord or that of its agents or employees.

6.05 DELAYS IN FURNISHING SERVICES
Tenant agrees that Landlord shall not be in breach of this Lease nor be liable
to Tenant for damages or otherwise, for any failure to furnish, or a delay in
furnishing, or a change in the quantity or character of any service, including
but not limited to phone services as set forth in Section 6.04 hereof, when such
failure or delay is occasioned, in whole or in part, by repairs, improvements or
mechanical breakdowns by the act or default of Tenant or other parties or by an
event of Force Majeure. No such failure or delay shall be deemed to be an
eviction or disturbance of Tenant's use and possession of the Premises, or
relieve Tenant from paying Rent or from performing any other obligations of
Tenant under this Lease, without any deduction or offset. Failure to any extent
to make available, or any slowdown, stoppage, or interruption of, the specified
utility services resulting from Landlord's compliance with any voluntary or
similar governmental or business

                                       15
<PAGE>

guidelines now or hereafter published or any requirements now or hereafter
established by any governmental agency, board, or bureau having jurisdiction
over the operation of the Building shall not render Landlord liable in any
respect for damages to either persons, property, or business, nor be construed
as an eviction of Tenant or work an abatement of Rent, nor relieve Tenant of
Tenant's obligations for fulfillment of any covenant or agreement hereof. Should
any equipment or machinery furnished by Landlord break down or for any cause
cease to function properly, Landlord shall use reasonable diligence to repair
same promptly, but Tenant shall have no claim for abatement of Rent or damages
on account of any interruption of service occasioned thereby or resulting
therefrom, except as specifically set forth in this Lease.

     Notwithstanding the above, except for the interruption of the foregoing
services arising by reason of fire or casualty loss provided for in Article 14,
any interruption of the foregoing services which "materially interferes" with
Tenant's use of any part of the Premises (other than an interruption of such
services caused by the act or default of Tenant, its employees, agents,
customers or invitees) for a period of ten (10) consecutive days after notice by
Tenant to Landlord of such interruption of service shall entitle Tenant to abate
the Monthly Base Rent and Rent Adjustment under this Lease for that portion of
the Premises which are untenantable for the period commencing on the eleventh
(11/th/) day of interruption of such services and terminating on the day of
restoration of the services.  For purposes of this Section 6.05, material
interference with Tenant's use of the Premises shall occur when Tenant shall be
prevented from using the Premises for general office purposes as a consequence
of Landlord's inability to provide the services specified in Section 6.01.  In
no event shall Landlord be liable for any damages, consequential or otherwise.
In the event that any of the services referred to in Article Six are not
provided for an aggregate of one hundred eighty (180) days during any twelve
(12) month period and said lack of services is deemed to be a material and
substantial interference with the business of Tenant and such interruption is
due to the fault of Landlord and/or its service provider and not the fault of a
service provider selected by Tenant, Tenant may then terminate this Lease by
giving Landlord ten (10) days written notice of its intention to terminate the
Lease (the "Casualty Termination Notice"), which termination shall be effective
on the tenth day after the date of such Casualty Termination Notice.  If
Landlord gives Tenant notice within said ten (10) day period that it will be
able to complete the repairs to the Premises within the next sixty (60) days,
the Casualty Termination Notice will be null and void and the Lease will remain
in full force and effect as if the Casualty Termination Notice had never been
given. In the event that Landlord fails to complete the repairs to the Premises
within said sixty (60) day period, Tenant may again exercise its right to
terminate this Lease by giving Landlord the Casualty Termination Notice as set
forth above, and the termination shall be effective on the tenth day after the
date of such Casualty Termination Notice.

6.06 CHOICE OF SERVICE PROVIDER

Tenant acknowledges that Landlord may, at Landlord's sole option, to the extent
permitted by applicable law, elect to change, from time to time, the company or
companies which provide services (including, without limitation, electrical
service, gas service and water) to the Building, the Premises and/or its
occupants. Landlord shall endeavor to give Tenant not less than thirty (30) days
notice of any scheduled change. Notwithstanding anything to the contrary set
forth in this Lease, Tenant acknowledges that Landlord has not and does not make
any representations or warranties concerning the identity or identities of the
company or companies which provide services to the

                                       16
<PAGE>

Building and the Premises or its occupants and Tenant acknowledges that the
choice of service providers and matters concerning the engagement and
termination thereof shall be solely that of Landlord. The foregoing provision is
not intended to modify, amend, change or otherwise derogate any provision of
this Lease concerning the nature or type of service to be provided or any
specific information concerning the amount thereof to be provided. Tenant agrees
to cooperate with Landlord and each of its service providers in connection with
any change in service or provider.

                                 ARTICLE SEVEN
                   POSSESSION, USE AND CONDITION OF PREMISES

7.01 POSSESSION AND USE OF PREMISES

     (a)  Tenant is already in possession of the Initial Premises under the
Prior Lease. Tenant shall occupy and use the Premises only for the uses
specified in Section 1.01(14) to conduct Tenant's business.

     Notwithstanding the foregoing, Tenant's use of the Premises will include
use of mail carts for internal deliveries on the passenger elevators and
Landlord agrees to such use provided such carts are approved by Landlord and
provided such use does not unreasonably interfere with use by other tenants of
the Building.

     Tenant shall not occupy or use the Premises (or permit the use or occupancy
of the Premises) for any purpose or in any manner which: (1) is unlawful or in
violation of any Law or Environmental Law; (2) may be dangerous to persons or
property or which may increase the cost of, or invalidate, any policy of
insurance carried on the Building or covering its operations; (3) is contrary to
or prohibited by the terms and conditions of this Lease or the rules of the
Building set forth in Article Eighteen; or (4) would tend to create or continue
a nuisance.

     (b)  Tenant as to the Premises and Landlord as to the Property excepting
the Premises shall each comply with all Environmental Laws concerning the proper
storage, handling and disposal of any Hazardous Material. Tenant shall not
generate, store, handle or dispose of any Hazardous Material in, on, or about
the Property without the prior written consent of Landlord, except that Tenant
may use and store small quantities of cleaning and office supplies which may
constitute Hazardous Materials, so long as such use and storage complies with
all applicable Laws. In the event that Tenant is notified of any investigation
or violation of any Environmental Law arising from Tenant's activities at the
Premises, Tenant shall immediately deliver to Landlord a copy of such notice. In
such event or in the event Landlord reasonably believes that a violation of
Environmental Law exists, subject to the terms of this Lease, Landlord may
conduct such tests and studies relating to compliance by Tenant with
Environmental Laws or the alleged presence of Hazardous Materials upon the
Premises as Landlord deems reasonably desirable, all of which shall be completed
at Tenant's expense; provided (i) Landlord gives Tenant reasonable prior notice;
Landlord and Tenant reach a reasonable agreement as to the scheduling of such
tests and studies; and (iii) Landlord does not materially, adversely affect
Tenant's use and occupancy of the Premises and does not cause damage to Tenant's
equipment and leasehold improvements. Landlord's inspection and testing rights
are for Landlord's own protection only, and Landlord has not, and shall not be
deemed to have assumed any responsibility to Tenant or any other party for
compliance with Environmental Laws, as a result of the exercise, or non-exercise
of such

                                       17
<PAGE>

rights. In the event Tenant, its agents, servants and/or employees introduces to
the Premises during the Lease Term any Hazardous Material, Tenant shall
indemnify, defend, protect and hold harmless Landlord and any Mortgagee or
Ground Lessor from any and all Premises related clean up losses, claims,
expenses, liability and costs (including reasonable attorneys' fees) which
Landlord may incur by reason of Tenant's introduction to the Premises during the
Lease Term of Hazardous Material. If any Hazardous Material is released,
discharged or disposed of on or about the Property and such release, discharge
or disposal is not caused by Tenant or other occupants of the Premises, or their
employees, agents or contractors, such release, discharge or disposal shall be
deemed casualty damage under Article Fourteen to the extent that the Premises
are affected thereby; in such case, Landlord and Tenant shall have the
obligations and rights respecting such casualty damage provided under such
Article. Any indemnification, exculpation or waiver provision under this Section
7.01(b) shall not be deemed to exculpate or indemnify Landlord against its own
negligence or that of its agents, or servants or employees.

     Notwithstanding anything to the contrary contained in the foregoing,
Landlord represents that, to the best of Landlord's knowledge, on the date this
Lease is fully executed, the Premises and the Building are in compliance of all
Environmental Laws concerning the proper storage, handling and disposal of any
Hazardous Material.  For purposes of this representation, "to the best of
Landlord's knowledge" shall mean the knowledge of Owner's Representative.

     (c)  Landlord and Tenant acknowledge that the Americans With Disabilities
Act of 1990 (42 U.S.C (S)12101 et seq.) and regulations and guidelines
promulgated thereunder, as all of the same may be amended and supplemented from
time to time (collectively referred to herein as the "ADA") establish
requirements for business operations, accessibility and barrier removal, and
that such requirements may or may not apply to the Premises and the Building
depending on, among other things: (1) whether Tenant's business is deemed a
"public accommodation" or "commercial facility", (2) whether such requirements
are "readily achievable", and (3) whether a given alteration affects a "primary
function area" or triggers "path of travel" requirements.  The parties hereby
agree that: (a) Landlord shall be responsible for ADA Title III compliance in
the Common Areas, except as provided below, (b) Tenant shall be responsible for
ADA Title III compliance in the Premises, including any leasehold improvements
or other work to be performed in the Premises under or in connection with this
Lease, (c) Tenant shall be responsible for the cost of, ADA Title III "path of
travel" requirements triggered by alterations in the Premises, and (d) Tenant
shall be responsible for the cost of, ADA Title III compliance in the Common
Areas necessitated by the Building being deemed to be a "public accommodation"
instead of a "commercial facility" as a result of Tenant's use of the Premises.
Tenant shall be solely responsible for requirements under Title I of the ADA
relating to Tenant's employees.

     Landlord represents that, to the best of Landlord's knowledge, on the date
this Lease is executed, the Building and the Common Areas are in compliance with
the ADA.  For purposes of this representation, "to the best of Landlord's
knowledge" shall mean the knowledge of Owner's Representative.

                                       18
<PAGE>

7.02 LANDLORD ACCESS TO PREMISES, APPROVALS

     (a)  Tenant shall permit Landlord to erect, use and maintain pipes, ducts,
wiring and conduits in and through the Premises, so long as Tenant's use, layout
or design of the Premises is not materially affected or altered.  Landlord or
Landlord's agents shall have the right to enter upon the Premises in the event
of an emergency, or, after twenty-four (24) hours advance notice to Tenant and
the opportunity to have a representative present, to inspect the Premises, to
perform janitorial and other services, to conduct safety and other testing in
the Premises and to make such routine repairs, alterations, improvements or
additions to the Premises or the Building or other parts of the Property as
Landlord may deem necessary or desirable including, without limitation, all
alterations, improvements and additions in connection with a change in service
provider or providers). Janitorial and cleaning services shall be performed
after normal business hours.  In connection therewith, Landlord shall be allowed
to store on the Premises all necessary supplies and materials. Any entry by
Landlord for any purpose other than in an emergency may be during normal
business hours, upon notice, given at least twenty-four (24) hours in advance
and Landlord shall use reasonable efforts to ensure that any such entry shall
not materially interfere with Tenant's occupancy of the Premises. An emergency
exists where entry is necessary, in Landlord's reasonable judgment, to prevent
or lessen injury to persons or property.

     (b)  If Landlord's entry is to make routine repairs, alterations,
improvements or additions to the Premises or the Building which do not cause any
disruption to Tenant's business, Tenant need not be personally present to permit
such entry into the Premises, but may choose to do so in connection with the
provisions of subsection (a) above.  However, when for any other reason an entry
therein shall be necessary or permissible, Landlord (or Landlord's agents),
after attempting to notify Tenant (unless Landlord believes an emergency
situation exists), may enter the Premises without rendering Landlord or its
agents liable therefor (if during such entry Landlord or Landlord's agent shall
accord reasonable care to Tenant's property), and without relieving Tenant of
any obligations under this Lease.

     (c)  Landlord may enter the Premises for the purpose of conducting such
inspections, tests and studies as Landlord may deem desirable or necessary to
confirm Tenant's compliance with all Laws and Environmental Laws or for other
purposes necessary in Landlord's reasonable judgment to ensure the sound
condition of the Building and the systems serving the Building so long as
Landlord (i) does not materially, adversely affect Tenant's use and occupancy of
the Premises, (ii) does not cause damage to Tenant's equipment and leasehold
improvements and (iii) complies with the provisions of this Section 7.02.
Landlord's rights under this Section 7.02(c) are for Landlord's own protection
only, and Landlord has not, and shall not be deemed to have assumed any
responsibility to Tenant or any other party for compliance with Laws or
Environmental Laws, as a result of the exercise or non-exercise of such rights.

     (d)  Landlord may do any of the foregoing, or undertake any of the
inspection or work described in the preceding paragraphs without such action
constituting an actual or constructive eviction of Tenant, in whole or in part,
or giving rise to an abatement of Rent by reason of loss or interruption of
business of the Tenant, or otherwise.

                                       19
<PAGE>

7.03 QUIET ENJOYMENT

Landlord covenants that so long as Tenant is in compliance with the covenants
and conditions set forth in this Lease, Tenant shall have the right to quiet
enjoyment of the Premises without hindrance or interference from Landlord or
those claiming through Landlord, and subject to the rights of any Mortgagee or
ground lessor.

                                 ARTICLE EIGHT
                                  MAINTENANCE

8.01 LANDLORD'S MAINTENANCE

Subject to the provisions of Article Fourteen, Landlord shall maintain and make
necessary repairs to the foundations, roofs, exterior walls, and the structural
elements of the Building, the electrical, plumbing, heating, ventilating and
air-conditioning, mechanical, communication, security and the fire and life
safety systems of the Building and those corridors, washrooms and lobbies which
are Common Areas of the Building in compliance with all Laws and in a manner
consistent with Class A Properties in downtown Chicago, except that: (a)
Landlord shall not be responsible for the maintenance or repair of any floor or
wall coverings in the Premises or any of such systems which are located within
the Premises and are supplemental or special to the Building's standard systems;
and (b) the cost of performing any of said maintenance or repairs whether to the
Premises or to the Building caused by the negligence of Tenant, its employees,
agents, servants, licensees, subtenants, contractors or invitees, shall be paid
by Tenant, subject to the waivers set forth in Section 16.04. Landlord shall not
be liable to Tenant for any expense, injury, loss or damage resulting from work
done in or upon, or in connection with the use of, any adjacent or nearby
building, land, street, or alley.

8.02 TENANT'S MAINTENANCE

Subject to the provisions of Article Fourteen, Tenant, at its expense, shall
keep and maintain the Premises and all Tenant Additions in good order, condition
and repair and in accordance with all Laws and Environmental Laws.  Tenant shall
not permit waste and shall promptly and adequately repair all damages to the
Premises and replace or repair all damaged or broken glass in the interior of
the Premises, fixtures or appurtenances.  Any repairs or maintenance shall be
completed with materials of similar quality to the original materials, all such
work to be completed under the supervision of Landlord.  Any such repairs or
maintenance shall be performed only by contractors or mechanics approved by
Landlord, which approval shall not be unreasonably withheld, and whose work will
not cause or threaten to cause disharmony or interference with Landlord or other
tenants in the Building and their respective agents and contractors performing
work in or about the Building.  If Tenant fails to perform or to diligently
commence performance of any of its obligations set forth in this Section 8.02,
Landlord may, in its sole discretion and upon 24 hours prior notice to Tenant
(except without notice in the case of emergencies), perform the same, and Tenant
shall pay to Landlord any costs or expenses incurred by Landlord upon demand.

                                       20
<PAGE>

                                 ARTICLE NINE
                         ALTERATIONS AND IMPROVEMENTS

9.01 TENANT'S ALTERATIONS

     (a)  Except for completion of Tenant Work undertaken by Tenant pursuant to
the Workletter in accordance with the provisions of Section 2.05, Article
Twenty-Seven, Article Twenty-Eight and Article Twenty-Nine of this Lease, the
following provisions shall apply to the completion of any Tenant Alterations:

          (i)  Tenant shall not, except as provided herein, without the prior
     written consent of Landlord, which consent shall not be unreasonably
     withheld, make or cause to be made any Tenant Alterations in or to the
     Premises or any Building systems serving the Premises.  Prior to making any
     Tenant Alterations, Tenant shall give Landlord ten (10) days prior written
     notice (or such earlier notice as would be necessary pursuant to applicable
     Laws) to permit Landlord sufficient time to post appropriate notices of
     non-responsibility.  Subject to all other requirements of this Article
     Nine, Tenant may undertake Decoration work and engage such contractors
     and/or subcontractors as Tenant desires without Landlord's prior written
     consent so long as such contractors and/ or subcontractors do not cause or
     threaten to cause disharmony or interference with Landlord or other tenants
     in the Building and their respective agents and contractors performing work
     in or about the Building.  Tenant shall furnish Landlord with the names and
     addresses of all contractors and subcontractors and copies of all
     contracts.  All Tenant Alterations shall be completed at such time and in
     such manner as Landlord may from time to time reasonably designate in
     cooperation with Tenant in order to minimize the time it takes and the cost
     of such Tenant Alterations, and only by contractors or mechanics approved
     by Landlord, which approval shall not be unreasonably withheld, and whose
     work will not cause or threaten to cause disharmony or interference with
     Landlord or other tenants in the Building and their respective agents and
     contractors performing work in or about the Building.  Landlord may further
     condition its consent upon Tenant furnishing to Landlord and Landlord
     approving prior to the commencement of any work or delivery of materials to
     the Premises related to the Tenant Alterations such of the following as
     specified by Landlord:  architectural plans and specifications, opinions
     from engineers reasonably acceptable to Landlord stating that the Tenant
     Alterations will not in any way adversely affect the Building's systems,
     including, without limitation, the mechanical, heating, plumbing, security,
     ventilating, air-conditioning, electrical, and the fire and life safety
     systems in the Building, necessary permits and licenses, including, but not
     limited to the substitution of Tenant's self-certification in connection
     therewith as may be acceptable to the City of Chicago Building Department
     from time to time, certificates of insurance, and such other documents in
     such form reasonably requested by Landlord.  Upon completion of the Tenant
     Alterations, Tenant shall deliver to Landlord final updated construction
     drawings and a digitized (if available) set of plans and specifications for
     the Tenant Alterations in connection with any affected area.

          (ii) Tenant shall pay the cost of all Tenant Alterations and the cost
     of decorating the Premises and any work to the Building occasioned thereby.
     In connection with completion of any Tenant Alterations, Landlord agrees it
     will not impose any fees of any

                                       21
<PAGE>

     nature upon Tenant for any Tenant Alterations performed pursuant to this
     section so long as Landlord is not supervising or acting in the capacity of
     general contractor or construction manager for such work. Upon completion
     of Tenant Alterations, Tenant shall furnish Landlord with contractors'
     affidavits and full and final waivers of lien and receipted bills covering
     all labor and materials expended and used in connection therewith and such
     other documentation reasonably requested by Landlord or Mortgagee.

          (iii)  Tenant agrees to complete all Tenant Alterations (i) in
     accordance with all Laws, Environmental Laws, all requirements of
     applicable insurance companies and in accordance with Landlord's standard
     construction rules and regulations, and (ii) in a good and workmanlike
     manner with the use of good grades of materials.  Tenant shall notify
     Landlord immediately if Tenant receives any notice of violation of any Law
     in connection with completion of any Tenant Alterations and shall
     immediately take such steps as are necessary to remedy such violation.  In
     no event shall such supervision or right to supervise by Landlord nor shall
     any approvals given by Landlord under this Lease constitute any warranty by
     Landlord to Tenant of the adequacy of the design, workmanship or quality of
     such work or materials for Tenant's intended use or of compliance with the
     requirements of Section 9.01(a)(3)(i) and (ii) above or impose any
     liability upon Landlord in connection with the performance of such work.

     (b)  All Tenant Additions whether installed by Landlord or Tenant, shall
without compensation or credit to Tenant, become part of the Premises and the
property of Landlord at the time of their installation and shall remain in the
Premises, unless pursuant to Article Twelve, Tenant may remove them or is
required to remove them at Landlord's request.

9.02 LIENS

Tenant shall not permit any lien or claim for lien of any mechanic, laborer or
supplier or any other lien to be filed against the Building, the Land, the
Premises, or any other part of the Property arising out of work performed, or
alleged to have been performed by, or at the direction of, or on behalf of
Tenant.  If any such lien or claim for lien is filed, Tenant shall within thirty
(30) days of receiving notice of such lien or claim (a) have such lien or claim
for lien released of record or (b) deliver to Landlord  a bond or other security
in form, content, amount, and issued by surety, reasonably satisfactory to
Landlord, indemnifying, protecting, defending and holding harmless the
Indemnitees against all costs and liabilities resulting from such lien or claim
for lien and the foreclosure or attempted foreclosure thereof.  If Tenant fails
to take any of the above actions, Landlord, in addition to its rights and
remedies under Article Eleven, without investigating the validity of such lien
or claim for lien, may pay or discharge the same and Tenant shall, as payment of
additional Rent hereunder, reimburse Landlord upon demand for the amount so paid
by Landlord, including Landlord's expenses and attorneys' fees.

                                       22
<PAGE>

                                  ARTICLE TEN
                           ASSIGNMENT AND SUBLETTING

10.01  ASSIGNMENT AND SUBLETTING

     (a)  Except as otherwise provided in this Section, without the prior
written consent of Landlord, Tenant may not sublease, assign, mortgage, pledge,
hypothecate or otherwise transfer or permit the transfer of this Lease or the
encumbering of Tenant's interest therein in whole or in part, by operation of
law or otherwise or permit the use or occupancy of the Premises, or any part
thereof, by anyone other than Tenant. If Tenant desires to enter into any
sublease of the Premises or assignment of this Lease, Tenant shall deliver
written notice thereof to Landlord ("Tenant's Notice"), together with the
identity of the proposed subtenant or assignee and the proposed principal terms
thereof and financial and other information sufficient for Landlord to make an
informed judgment with respect to such proposed subtenant or assignee at least
thirty (30) days prior to the commencement date of the term of the proposed
sublease or assignment. If Tenant proposes to sublease less than all of the
Rentable Area of the Premises, the space proposed to be sublet and the space
retained by Tenant must each be a marketable unit as reasonably determined by
Landlord and otherwise in compliance with all Laws. Landlord shall notify Tenant
in writing of its approval or disapproval of the proposed sublease or assignment
or its decision to exercise its rights under Section 10.02 within thirty (30)
days after receipt of Tenant's Notice (and all required information) and
Landlord's notification shall include the reasons for any disapproval. Tenant
shall submit for Landlord's approval (which approval shall not be unreasonably
withheld) any advertising which Tenant or its agents intend to use with respect
to the space proposed to be sublet.

     (b)  With respect to Landlord's consent to an assignment or sublease,
Landlord may take into consideration any factors which Landlord may deem
reasonably relevant, and the reasons for which Landlord's denial shall be deemed
to be reasonable shall include, without limitation, the following:

          (i)   in Landlord's reasonable judgment, the business reputation or
     credit standing of any proposed assignee is not acceptable to Landlord; or

          (ii)  in Landlord's reasonable judgment, any proposed assignee's or
     sublessee's use of the Premises would breach Section 7.01 of the Lease or
     would breach the provisions of any other leases of tenants in the Building;
     or

          (iii) the proposed assignee or sublessee is either a governmental
     agency, a school or similar operation, or a medical related practice
     unless, prior to Tenant's request, Landlord has entered into a lease with a
     substantially similar medical related practice, in which case Landlord
     shall not deny Tenant's request to sublease the Premises or assign the
     Lease to such entity merely on that basis; or

          (iv)  the proposed sublessee or assignee is an existing tenant and
     Landlord is able to accommodate such sublessee or assignee in other space
     in the Building; provided, however, that if Landlord does not have the
     space in the building to accommodate the proposed sublessee or assignee
     (i.e. the proposed sublessee or assignee is in need of 10,000 rentable
     square feet and there is less then 10,000 rentable square feet available in
     a

                                       23
<PAGE>

     contiguous suite in the building) then the fact that the sublessee or
     assignee is an existing tenant of the Building shall neither be a relevant
     factor in Landlord's determination whether to consent to such sublease or
     assignment nor a reason for Landlord's denial of such consent; or

     In the event Landlord sells the Building to an entity unrelated to
     Metropolitan Life Insurance Company, a New York corporation, then this
     subparagraph (iv) shall be replaced with the following:

          "the proposed sublessee or assignee is an existing tenant and Landlord
          is able to accommodate such sublessee or assignee in other space in
          the Building; provided, however, that if Landlord and Tenant's
          proposed sublessee or assignee cannot agree on the terms of a lease
          for other space in the Building within 120 days of Tenant's initial
          notification to Landlord that said proposed sublessee or assignee is
          interested in Tenant's space and thereafter cannot execute and deliver
          a lease for such other space in the Building within 180 days of
          Tenant's initial notification to Landlord that said proposed sublessee
          or assignee is interested in Tenant's space,"

          (v)   the proposed sublessee or assignee would negatively impact the
     pedestrian traffic to and from the Building; or

          (vi)  a Default then exists under the Lease, or a fact or condition
     exists, which but for the giving of notice or the passage of time would
     constitute a Default; or

          (vii) the assignment of the Lease would assign less than the entire
     Premises.

     (c)  If Landlord chooses not to recapture the space proposed to be
subleased or assigned as provided in Section 10.02, Landlord shall not
unreasonably withhold its consent to a subletting or assignment under this
Section 10.01. Any approved sublease or assignment shall be expressly subject to
the terms and conditions of this Lease. Any such subtenant or assignee shall
execute such documents as Landlord may reasonably require to evidence such
subtenant or assignee's assumption of such obligations and liabilities. Within a
reasonable period of time after the effective date of an assignment or sublease,
Tenant shall deliver to Landlord a copy of all agreements executed by Tenant and
the proposed subtenant and assignee with respect to the Premises. Landlord's
approval of a sublease or assignment shall not constitute a waiver of Tenant's
obligation to obtain Landlord's consent to further assignments or subleases.

     (d)  For purposes of this Article Ten, an assignment shall be deemed to
include a change in the majority control of Tenant, resulting from any transfer,
sale or assignment of shares of stock of Tenant occurring by operation of law or
otherwise if Tenant is a corporation whose shares of stock are not traded
publicly. If Tenant is a partnership, any change in the partners of Tenant
owning a majority interest in Tenant shall be deemed to be an assignment.

     (e)  Notwithstanding anything to the contrary contained in this Article
Ten, Tenant shall have the right, without the prior written consent of Landlord,
to sublease the Premises to an Affiliate, or to assign this Lease to an
Affiliate, provided, (i) prior to the effective date of the assignment or
sublease, Tenant gives Landlord written notice of its intention to assign or
sublease

                                       24
<PAGE>

and (ii) within a reasonable period of time after the effective date of the
assignment or sublease, the assignee or sublessee shall execute documents
reasonably satisfactory to Landlord to evidence such subtenant or assignee's
assumption of the obligations and liabilities of Tenant under this Lease, except
in the case of any assignment which occurs by operation of law (and without a
written assignment) as a consequence of merger, consolidation or non-bankruptcy
reorganization and (iii) within a reasonable period of time after the effective
date of such assignment or sublease, Tenant shall give notice to Landlord which
notice shall include the full name and address of the assignee or subtenant, a
copy of all agreements executed between Tenant and the assignee or subtenant
with respect to the Premises; and such documents or information which Landlord
reasonably requests for the purpose of substantiating whether or not the
assignment or sublease is to an Affiliate.

10.02  RECAPTURE

Except for subleases and assignments made pursuant to Section 10.01(e) to which
this Section 10.02 does not apply, and then only if Tenant proposes to sublet or
assign greater than 25% of its then leased space in the Building, Landlord shall
have the option to exclude from the Premises covered by this Lease
("recapture"), the space proposed to be sublet or subject to the assignment,
effective as of the proposed commencement date of such sublease or assignment.
If Landlord elects to recapture and gives Tenant notice of such election, Tenant
shall have ten (10) days in which to withdraw such sublease or assignment by
written notice to Landlord. If Landlord elects to recapture and Tenant does not
withdraw the request to sublease or assign, Tenant shall surrender possession of
the space proposed to be subleased or subject to the assignment to Landlord on
the effective date of recapture of such space from the Premises such date being
the Termination Date for such space. Effective as of the date of recapture of
any portion of the Premises pursuant to this section, the Monthly Base Rent,
Rentable Area of the Premises and Tenant's Share shall be adjusted accordingly.

10.03  EXCESS RENT

Except for subleases and assignments made pursuant to Section 10.01(e) and to
which Section 10.02 does not apply, Tenant shall pay Landlord on the first day
of each month during the term of the sublease or assignment, fifty percent (50%)
of the amount by which the sum of all rent and other consideration (direct or
indirect) due from the subtenant or assignee for such month exceeds: (i) that
portion of the Monthly Base Rent and Rent Adjustments due under this Lease for
said month which is allocable to the space sublet or assigned; and (ii) the
following costs and expenses for the subletting or assignment of such space: (1)
brokerage commissions and attorneys' fees and expenses, (2) advertising for
subtenants or assignees; (3) the actual costs paid in making any improvements or
substitutions in the Premises required by any sublease or assignment and (4)
"free rent" periods, costs of any inducements or concessions given to subtenant
or assignee, moving costs, and other amounts in respect of such subtenant's or
assignee's other leases or occupancy arrangements.

     In the event Landlord sells the Building to an entity unrelated to
Metropolitan Life Insurance Company, a new York corporation, then the following
language shall be added at this point in the document:

                                       25
<PAGE>

   "and (5) the annual unamortized portion of Tenant's leasehold improvements.
   Said leasehold improvements shall be capped at $100/rentable square foot (or
   the Year 2000 equivalent thereof as per RS Means Building Construction Cost
   Data or its equivalent or successor) on the sublease premises as defined
   herein and shall be capped at a proportionate share thereof at the time of
   any future sublease (taking into consideration, the length and point in time
   of such subleases)."

10.04  TENANT LIABILITY

In the event of any sublease or assignment, whether or not with Landlord's
consent, Tenant shall not be released or discharged from any liability, whether
past, present or future, under this Lease, including any liability arising from
the exercise of any renewal or expansion option, to the extent expressly
permitted by Landlord. Tenant's liability shall remain primary, and in the event
of default by any subtenant, assignee or successor of Tenant in performance or
observance of any of the covenants or conditions of this Lease, Landlord may
proceed directly against Tenant without the necessity of exhausting remedies
against said subtenant, assignee or successor. If Landlord grants consent to
such sublease or assignment, Tenant shall pay all reasonable attorneys' fees and
expenses incurred by Landlord with respect to such assignment or sublease.  In
addition, if Tenant has any options to extend the term of this Lease or to add
other space to the Premises, such options may be available to any subtenant or
assignee, directly or indirectly, upon Landlord's express written consent, which
may be withheld in Landlord's sole discretion, unless specifically provided
otherwise in this Lease.

10.05  ASSUMPTION AND ATTORNMENT

If Tenant shall assign this Lease as permitted herein, the assignee shall
expressly assume all of the obligations of Tenant hereunder in a written
instrument satisfactory to Landlord and furnished to Landlord not later than
fifteen (15) days prior to the effective date of the assignment.  If Tenant
shall sublease the Premises as permitted herein, Tenant shall, at Landlord's
option, within fifteen (15) days following any request by Landlord, obtain and
furnish to Landlord the written agreement of such subtenant to the effect that
the subtenant will attorn to Landlord and will pay all subrent directly to
Landlord.

                                ARTICLE ELEVEN
                             DEFAULT AND REMEDIES

11.01  EVENTS OF DEFAULT

The occurrence or existence of any one or more of the following shall constitute
a "Default" by Tenant under this Lease:

     (a)  Tenant fails to pay any installment or other payment of Rent including
Rent Adjustment Deposits or Rent Adjustments within five (5) days after the date
when due and such failure continues for five (5) business days after Landlord
sends Tenant a notice of default;

                                       26
<PAGE>

     (b)  Tenant fails to observe or perform any of the other covenants,
conditions or provisions of this Lease or the Workletter and fails to cure such
default within thirty (30) days after written notice thereof to Tenant;
provided, that if such default is not susceptible to being cured within such
thirty (30) day period but Tenant promptly commences and diligently pursues such
cure, said thirty (30) day period shall be extended so long as Tenant is
actively, diligently and continuously attempting to effectuate such cure (and
furnishing Landlord with weekly written status reports on such efforts), unless
the default involves a hazardous condition, which shall be cured forthwith, or
unless the failure to perform is a Default for which this Lease specifies there
is no cure or grace period;

     (c)  the interest of Tenant in this Lease is levied upon under execution or
other legal process;

     (d)  a petition is filed by or against Tenant to declare Tenant bankrupt or
seeking a plan of reorganization or arrangement under any Chapter of the
Bankruptcy Act, or any amendment, replacement or substitution therefor, or to
delay payment of, reduce or modify Tenant's debts, which in the case of an
involuntary action is not discharged within ninety (90) days;

     (e)  Tenant is declared insolvent by law or any assignment of Tenant's
property is made for the benefit of creditors;

     (f)  a receiver is appointed for Tenant or Tenant's property, which
appointment is not discharged within ninety (90) days;

     (g)  any action taken by or against Tenant to reorganize or modify Tenant's
capital structure in a materially adverse way which in the case of an
involuntary action is not discharged within sixty (60) days; or

     (h)  upon the dissolution of Tenant.

11.02  LANDLORD'S REMEDIES

     (a)  If a Default occurs, Landlord shall have the rights and remedies
hereinafter set forth, which shall be distinct and cumulative:  (i) Landlord may
terminate this Lease by giving Tenant notice of Landlord's election to do so, in
which event, the term of this Lease shall end and all of Tenant's rights and
interests shall expire on the date stated in such notice; (ii) Landlord may
terminate Tenant's right of possession of the Premises without terminating this
Lease by giving notice to Tenant that Tenant's right of possession shall end on
the date specified in such notice; or (iii) Landlord may enforce the provisions
of this Lease and may enforce and protect the rights of the Landlord hereunder
by a suit or suits in equity or at law for the specific performance of any
covenant or agreement contained herein, or for the enforcement of any other
appropriate legal or equitable remedy, including recovery of all monies due or
to become due for the balance of the Term from Tenant under any of the
provisions of this Lease.

     (b)  In the event that Landlord terminates the Lease, Landlord shall be
entitled to recover as damages for loss of the bargain and not as a penalty, the
present value of the excess, if any, of (i)

                                       27
<PAGE>

Rent for the balance of the Term, plus all Landlord's reasonable expenses of
reletting, including without limitation, repairs, alterations, improvements,
additions, decorations, legal fees and brokerage commissions (collectively, the
"Reletting Expenses"), over (ii) the aggregate amount of Rent actually collected
by Landlord for the Premises. In the event that Landlord receives a judgment
against Tenant before any Rent is actually collected by Landlord for the
Premises under this Section 11.02(b), Landlord shall recalculate the foregoing
upon the receipt of any such Rent and shall remit the excess, if any, to Tenant.

     (c)  In the event Landlord proceeds pursuant to subparagraph (a)(ii) above,
Landlord may, but shall not be obligated to (except as may be required by law),
relet the Premises, or any part thereof for the account of Tenant, for such rent
and term and upon such terms and conditions as are reasonably acceptable to
Landlord. For purposes of such reletting, Landlord is authorized to decorate,
repair, alter and improve the Premises to the extent reasonably necessary or
desirable. If the Premises are relet and the consideration realized therefrom
after payment of all Landlord's Reletting Expenses, is insufficient to satisfy
the payment when due of Rent reserved under this Lease for any monthly period,
then Tenant shall pay Landlord upon demand any such deficiency monthly. If such
consideration is greater than the amount necessary to pay the full amount of the
Rent, the full amount of such excess shall be retained by Landlord and shall in
no event be payable to Tenant. Tenant agrees that Landlord may file suit to
recover any sums due to Landlord hereunder from time to time and that such suit
or recovery of any amount due Landlord hereunder shall not be any defense to any
subsequent action brought for any amount not theretofore reduced to judgment in
favor of Landlord.

     (d)  In the event a Default occurs, Landlord may, at Landlord's option,
enter into the Premises, remove Tenant's property, fixtures, furnishings, signs
and other evidences of tenancy, and take and hold such property; provided,
however, that such entry and possession shall not terminate this Lease or
release Tenant, in whole or in part, from Tenant's obligation to pay the Rent
reserved hereunder for the full Term or from any other obligation of Tenant
under this Lease. Any and all property which may be removed from the Premises by
Landlord pursuant to the authority of the Lease or law, to which Tenant is or
may be entitled, may be handled, removed or stored by Landlord at the risk, cost
and expense of Tenant, and Landlord shall in no event be responsible for the
value, preservation or safekeeping thereof. Tenant shall pay Landlord, upon
demand, any and all reasonable expenses incurred in such removal and all storage
charges against such property so long as the same shall be in the Landlord's
possession or under the Landlord's control. Any such property of Tenant not
retaken from storage by Tenant within thirty (30) days after the Termination
Date, shall be conclusively presumed to have been conveyed by Tenant to Landlord
under this Lease as a bill of sale without further payment or credit by Landlord
to Tenant.

11.03  ATTORNEY'S FEES

Except as set forth in Article Thirty-Three of this Lease, Tenant shall pay upon
demand, all costs and expenses, including reasonable attorneys' fees, incurred
by Landlord in any litigation, negotiation or transaction in which Tenant causes
Landlord, without Landlord's fault, to become involved or concerned. Landlord
shall pay upon demand, all costs and expenses, including reasonable attorneys'
fees, incurred by Tenant in any litigation, negotiation or transaction in which
Landlord causes Tenant, without Tenant's fault, to become involved or concerned.
In the case of a

                                       28
<PAGE>

dispute between the parties hereto, the prevailing party in such dispute shall
not be responsible for its attorney fees and the other party shall pay all such
costs.

11.04  BANKRUPTCY

The following provisions shall apply in the event of the bankruptcy or
insolvency of Tenant:

     (a)  In connection with any proceeding under Chapter 7 of the Bankruptcy
Code where the trustee of Tenant elects to assume this Lease for the purposes of
assigning it, such election or assignment, may only be made upon compliance with
the provisions of (b) and (c) below, which conditions Landlord and Tenant
acknowledge to be commercially reasonable. In the event the trustee elects to
reject this Lease then Landlord shall immediately be entitled to possession of
the Premises without further obligation to Tenant or the trustee.

     (b)  Any election to assume this Lease under Chapter 11 or 13 of the
Bankruptcy Code by Tenant as debtor-in-possession or by Tenant's trustee (the
"Electing Party") must provide for:

          The Electing Party to cure or provide to Landlord adequate assurance
that it will cure all monetary defaults under this Lease within fifteen (15)
days from the date of assumption and it will cure all non-monetary defaults
under this Lease within thirty (30) days from the date of assumption. Landlord
and Tenant acknowledge such condition to be commercially reasonable.

     (c)  If the Electing Party has assumed this Lease or elects to assign
Tenant's interest under this Lease to any other person, such interest may be
assigned only if the intended assignee has provided adequate assurance of future
performance (as herein defined), of all of the obligations imposed on Tenant
under this Lease.

          For the purposes hereof, "adequate assurance of future performance"
means that Landlord has ascertained that each of the following conditions has
been satisfied:

          The assignee has submitted a current financial statement, certified by
its chief financial officer, which shows a net worth and working capital in
amounts sufficient to assure the future performance by the assignee of Tenant's
obligations under this Lease; and

          Landlord has obtained consents or waivers from any third parties which
may be required under a lease, mortgage, financing arrangement, or other
agreement by which Landlord is bound, to enable Landlord to permit such
assignment.

     (d)  Landlord's acceptance of rent or any other payment from any trustee,
receiver, assignee, person, or other entity will not be deemed to have waived,
or waive, the requirement of Landlord's consent, Landlord's right to terminate
this Lease for any transfer of Tenant's interest under this Lease without such
consent, or Landlord's claim for any amount of Rent due from Tenant.

                                       29
<PAGE>

11.05  LANDLORD'S DEFAULT

Landlord shall be in default hereunder in the event Landlord has not begun and
pursued with reasonable diligence the cure of any failure of Landlord to meet
its obligations hereunder within thirty (30) days of the receipt by Landlord of
written notice from Tenant of the alleged failure to perform. In no event shall
Tenant have the right to terminate or rescind this Lease as a result of
Landlord's default as to any covenant or agreement contained in this Lease.
Tenant hereby waives such remedies of termination and rescission and hereby
agrees that Tenant's remedies for default hereunder and for breach of any
promise or inducement shall be limited to a suit for damages and/or injunction.
In addition, Tenant hereby covenants that, prior to the exercise of any such
remedies, it will give the mortgagees holding mortgages on the Building notice
and a reasonable time to cure any default by Landlord as set forth in Section
23.02.

     Notwithstanding anything to the contrary contained in this Lease, if
Landlord shall at any time be in default in the performance of any obligation
under this Lease and Tenant shall have obtained a monetary judgment from a court
of competent jurisdiction, which judgment is not subject to appeal or otherwise
stayed by Landlord and which judgment had not been paid by Landlord to Tenant
within sixty (60) days after final entry, Tenant shall have the right to offset
the amount of such monetary judgment against payment of the next succeeding
payments of Rent (including, without limitation, Rent Adjustments) due under
this Lease upon prior written notice to Landlord of its intention to do so.

                                ARTICLE TWELVE
                             SURRENDER OF PREMISES

12.01  IN GENERAL

Upon the Termination Date, Tenant shall surrender and vacate the Premises
immediately and deliver possession thereof to Landlord in a clean, good and
tenantable condition, ordinary wear and tear, and damage caused by Landlord
excepted. Tenant shall deliver to Landlord all keys to the Premises. Tenant
shall remove from the Premises all movable personal property of Tenant and
Tenant's trade fixtures. Tenant shall be entitled to remove such Tenant
Additions which at the time of their installation Landlord and Tenant agreed may
be removed by Tenant. In addition, Landlord shall designate, concurrently with
written consent of Tenant's alteration plans, which permanently attached and
moveable additions, non-trade fixtures, equipment and other improvements, if
any, Tenant shall be required to remove upon Lease termination, and such
designation shall not be subject to amendment except by written agreement
between Landlord  and Tenant.  Tenant shall also remove such other Tenant
Additions as required by Landlord, including, but not limited to, any Tenant
Additions containing Hazardous Materials. Notwithstanding anything to the
contrary contained herein, Landlord and Tenant hereby agree that Exhibit H
                                                                 ---------
attached hereto and made a part hereof contains a list of categories for
removal.  The types of items listed thereon shall also be removed by Tenant.
Tenant immediately shall repair all damage resulting from removal of any of
Tenant's property, furnishings or Tenant Additions and shall restore the
Premises to a tenantable condition as reasonably determined by Landlord. In the
event possession of the Premises is not delivered to Landlord when required
hereunder, or if Tenant shall fail to remove those items described herein,
Landlord may (but shall not be obligated to), at

                                       30
<PAGE>

Tenant's expense, remove any of such property and store, sell or otherwise deal
with such property as provided in Section 11.02(d), including the waiver and
indemnity obligations provided in that Section, and undertake, at Tenant's
expense such restoration work as Landlord deems necessary or advisable.

     Notwithstanding anything to the contrary contained herein, Tenant shall, at
its sole cost and expense, demolish and remove the Bridge and repair any damage
occasioned thereby, including, without limitation, restoration of the facade of
the Building, prior to expiration of the Term hereof or upon any termination of
this Lease or Tenant's possession under this Lease.

12.02  LANDLORD'S RIGHTS

All property which may be removed from the Premises by Landlord shall be
conclusively presumed to have been abandoned by Tenant and Landlord may deal
with such property as provided in Section 11.02(d). Tenant shall also reimburse
Landlord for all costs and expenses incurred by Landlord in removing any of
Tenant Additions and in restoring the Premises to the condition required by this
Lease at the Termination Date.

                               ARTICLE THIRTEEN
                                 HOLDING OVER

Tenant shall pay Landlord double the monthly Rent payable for the month
immediately preceding the holding over (including increases for Rent Adjustments
which Landlord may reasonably estimate) for each month or portion thereof that
Tenant retains possession of the Premises, or any portion thereof, after the
Termination Date (without reduction for any partial month that Tenant retains
possession). Tenant shall also pay all damages sustained by Landlord by reason
of such retention of possession. The provisions of this Article shall not
constitute a waiver by Landlord of any re-entry rights of Landlord and Tenant's
continued occupancy of the Premises shall be as a tenancy in sufferance.

                               ARTICLE FOURTEEN
                       DAMAGE BY FIRE OR OTHER CASUALTY

14.01  SUBSTANTIAL UNTENANTABILITY

     (a)  If any fire or other casualty (whether insured or uninsured) renders
all or a substantial portion of the Premises or the Building untenantable,
Landlord shall, within sixty (60) days after the occurrence of such damage,
estimate the length of time that will be required to Substantially Complete the
repair and restoration and shall by notice advise Tenant of such estimate
("Landlord's Notice"). If Landlord estimates that the amount of time required to
Substantially Complete such repair and restoration will exceed one hundred
eighty (180) days from the date such damage occurred, then Landlord, or Tenant
if (i) all or a substantial portion of the Premises is rendered untenantable or
(ii) a substantial portion of the Building is rendered untenantable or the
portion directly affects Tenant's access to the Premises or its ability to use
the Common Areas, shall have the right to terminate this Lease as of the date of
such damage upon giving written notice to the other at any time within twenty
(20) days after delivery of Landlord's Notice, provided that if

                                       31
<PAGE>

Landlord so chooses, Landlord's Notice may also constitute such notice of
termination. In addition, if such damage is to the Premises and occurs during
the last twelve (12) months of the Term, either Tenant or Landlord shall have
the right to terminate this Lease as of the date of such casualty by giving
written notice thereof to the other within twenty (20) days after the date of
such casualty.

     As used in this Lease "untenantable" means reasonably incapable of being
occupied for its intended use due to damage to the Premises or Building.
Notwithstanding anything to the contrary contained herein, neither the Premises
nor any portion of the Premises shall be deemed untenantable if Landlord is not
required to repair or restore same (or if Landlord is required to repair or
restore same, then following such time as Landlord has Substantially Completed
the repair or restoration work required to be performed by Landlord) or if
Tenant continues to actually occupy the subject portion of the Premises for the
ordinary conduct of its business (and not just for the retrieval of files and
other information necessary to continue its business operations at another
location).

     (b)  Unless this Lease is terminated as provided in the preceding
subparagraph, Landlord shall proceed with reasonable promptness to repair and
restore the Premises to its condition as existed prior to such casualty, subject
to reasonable delays for insurance adjustments and Force Majeure delays, and
also subject to zoning laws and building codes then in effect. Landlord shall
have no liability to Tenant, and Tenant shall not be entitled to terminate this
Lease if such repairs and restoration are not in fact completed within the time
period estimated by Landlord so long as Landlord shall proceed with reasonable
diligence to complete such repairs and restoration.

     (c)  Tenant acknowledges that Landlord shall be entitled to the full
proceeds of any insurance coverage, whether carried by Landlord or Tenant, for
damages to the Premises, except for those proceeds of Tenant's insurance of its
own personal property, fixtures and equipment which would be or are required to
be removable by Tenant at the Termination Date. All such insurance proceeds
shall be payable to Landlord whether or not the Premises are to be repaired and
restored.

     (d)  Notwithstanding anything to the contrary herein set forth: (i)
Landlord shall have no duty pursuant to this Section to repair or restore any
portion of any Tenant Additions or to expend for any repair or restoration of
the Premises or Building amounts in excess of insurance proceeds paid to
Landlord and available for repair or restoration plus any deductible amounts
applicable thereto; and (ii) Tenant shall not have the right to terminate this
Lease pursuant to this Section if any damage or destruction was caused by the
act or neglect of Tenant, its agent or employees.

     (e)  Any repair or restoration of the Premises performed by Tenant shall be
in accordance with the provisions of Article Nine hereof.

14.02  INSUBSTANTIAL UNTENANTABILITY

If the Premises or the Building is damaged by a casualty but neither is rendered
substantially untenantable and Landlord estimates, within sixty (60) days after
the occurrence of such damage, that the time to Substantially Complete the
repair or restoration will not exceed one hundred eighty

                                       32
<PAGE>

(180) days from the date such damage occurred, then Landlord shall proceed to
repair and restore the Building or the Premises other than Tenant Additions,
with reasonable promptness, unless such damage is to the Premises and occurs
during the last twelve (12) months of the Term, in which event either Tenant or
Landlord shall have the right to terminate this Lease as of the date of such
casualty by giving written notice thereof to the other within twenty (20) days
after the date of such casualty. [Notwithstanding the aforesaid, Landlord's
obligation to repair shall be limited in accordance with the provisions of
Section 14.01 (d)(i) above.]

14.03  RENT ABATEMENT

Except for the negligence or willful misconduct of Tenant or its agents,
employees, contractors or invitees, if all or any part of the Premises are
rendered untenantable by fire or other casualty and this Lease is not
terminated, Monthly Base Rent and Rent Adjustments shall abate for that part of
the Premises which is untenantable on a per diem basis from the date of the
casualty until sixty (60) days after Landlord has Substantially Completed the
repair and restoration work in the Premises which it is required to perform.

                                ARTICLE FIFTEEN
                                EMINENT DOMAIN

15.01  TAKING OF WHOLE OR SUBSTANTIAL PART

In the event the whole or any substantial part of the Building or of the
Premises is taken or condemned by any competent authority for any public use or
purpose (including a deed given in lieu of condemnation) and is thereby rendered
untenantable, this Lease shall terminate as of the date title vests in such
authority, and Monthly Base Rent and Rent Adjustments shall be apportioned as of
the Termination Date. Notwithstanding anything to the contrary herein set forth,
in the event the taking is temporary (for less than one hundred eighty (180)
days), Landlord may elect either (i) to terminate this Lease or (ii) permit
Tenant to receive the entire award with respect to the Premises in which case
Tenant shall continue to pay Rent and this Lease shall not terminate.

15.02  TAKING OF PART

In the event a part of the Building or the Premises is taken or condemned by any
competent authority (or a deed is delivered in lieu of condemnation) and
Landlord estimates, within sixty (60) days after the occurrence of such taking,
that the time to Substantially Complete the repair or restoration will not
exceed one hundred eighty (180) days from the date of such taking, then
Landlord, upon receipt and to the extent of the award in condemnation (or
proceeds of sale) shall make necessary repairs and restorations to the Premises
(exclusive of Tenant Additions) and to the Building to the extent necessary to
constitute the portion of the Building not so taken or condemned as a complete
architectural and economically efficient unit, unless such taking is to the
Premises and occurs during the last twelve (12) months of the Term, in which
event either Tenant or Landlord shall have the right to terminate this Lease as
of the date of such taking by giving written notice thereof to the other within
twenty (20) days after the date of such casualty.

                                       33
<PAGE>

     In the event a part of the Building or the Premises is taken or condemned
by any competent authority (or a deed is delivered in lieu of condemnation) and
this Lease is not terminated, the Lease shall be amended to reduce the Monthly
Base Rent and reduce or increase, as the case may be, Tenant's Proportionate
Share to reflect the Rentable Area of the Premises or Building, as the case may
be, remaining after any such taking or condemnation. Notwithstanding the
foregoing, if as a result of any taking, or a governmental order that the grade
of any street or alley adjacent to the Building is to be changed and such taking
or change of grade makes it necessary or desirable to substantially remodel or
restore the Building or prevents the economical operation of the Building,
Landlord shall have the right to terminate this Lease upon ninety (90) days
prior written notice to Tenant.

15.03  COMPENSATION

Landlord shall be entitled to receive the entire award (or sale proceeds) from
any such taking, condemnation or sale without any payment to Tenant, and Tenant
hereby assigns to Landlord Tenant's interest, if any, in such award; provided,
however, Tenant shall have the right separately to pursue against the condemning
authority a separate award in respect to any damages sustained by Tenant,
including without limitation, Tenant's relocation expenses, loss to Tenant's
business, and the like, and of the loss, if any, to Tenant Additions paid for by
Tenant minus any credit or allowance from Landlord so long as there is no
diminution of Landlord's award as a result.

                                ARTICLE SIXTEEN
                                   INSURANCE

16.01  TENANT'S INSURANCE

Tenant, at Tenant's expense, agrees to maintain in force, with a company or
companies reasonably acceptable to Landlord, during the Term: (a) Commercial
General Liability Insurance on a primary basis and without any right of
contribution from any insurance carried by Landlord covering the Premises on an
occurrence basis against all claims for personal injury, bodily injury, death
and property damage, including contractual liability covering the
indemnification provisions in this Lease. Such insurance shall be for such
limits that are reasonably required by Landlord from time to time but not less
than a combined single limit of Three Million and No/100 Dollars
($3,000,000.00); (b) Workers' Compensation and Employers' Liability Insurance
for an amount of not less than One Million and No/100 Dollars ($1,000,000.00),
both in accordance with the laws of The State of Illinois; (c) "All Risks"
property insurance in an amount adequate to cover the full replacement cost of
all equipment, installations, fixtures and contents of the Premises, including
the Bridge and the Antennae Siote as set forth in Exhibit I attached to this
Lease, in the event of loss and any such policy shall contain a provision
requiring the insurance carriers to waive their rights of subrogation against
Landlord. For the purposes of this Article Sixteen, the Premises will include
the Bridge or any bridge constructed by Tenant adjoining the Premises and the
Antennae Site, if the Satellite License Agreement is entered into. So long as
the Bridge or any such bridge is in place, the limit of comprehensive
generalliability insurance shall not be less than $10,000,000; (d) In the event
a motor vehicle is to be used by Tenant in connection with its business
operation from the Premises, Comprehensive Automobile Liability Insurance
coverage with limits of not less than One Million and No/100 Dollars
($1,000,000.00) combined single limit coverage against bodily injury

                                       34
<PAGE>

liability and property damage liability arising out of the use by or on behalf
of Tenant, its agents and employees in connection with this Lease, of any owned,
non-owned or hired motor vehicles; and (e) such other insurance or coverages as
Landlord reasonably requires.

16.02  FORM OF POLICIES

Each policy referred to in 16.01 shall satisfy the following requirements. Each
policy shall (i) name Landlord and the Indemnitees as additional insureds
(except Workers' Compensation and Employers' Liability Insurance), (ii) be
issued by one or more responsible insurance companies licensed to do business in
the state of Illinois and reasonably satisfactory to Landlord, (iii) where
applicable, provide for deductible amounts satisfactory to Landlord and not
permit co-insurance, (iv) shall provide that such insurance may not be canceled
or amended without thirty (30) days' prior written notice to the Landlord, and
(v) shall provide that the policy shall not be invalidated should the insured
waive in writing prior to a loss, any or all rights of recovery against any
other party for losses covered by such policies. Tenant shall deliver to
Landlord, certificates of insurance and at Landlord's request, copies of all
policies and renewals thereof to be maintained by Tenant hereunder, not less
than ten (10) days prior to the Commencement Date and not less than ten (10)
days prior to the expiration date of each policy.

16.03  LANDLORD'S INSURANCE

Landlord agrees to purchase and keep in full force and effect during the Term
hereof, including any extensions or renewals thereof, insurance under policies
issued by insurers of recognized responsibility, qualified to do business in
Illinois on the Building in amounts not less than the greater of eighty (80%)
percent of the then full replacement cost (without depreciation) of the Building
(above foundations) or an amount sufficient to prevent Landlord from becoming a
co-insurer under the terms of the applicable policies, against fire and such
other risks as may be included in standard forms of all risk coverage insurance
reasonably available from time to time. Landlord agrees to maintain in force
during the Term, Commercial General Liability Insurance covering the Building on
an occurrence basis against all claims for personal injury, bodily injury, death
and property damage. Such insurance shall be for a combined single limit of Five
Million and No/100 Dollars ($5,000,000.00). Neither Landlord's obligation to
carry such insurance nor the carrying of such insurance shall be deemed to be an
indemnity by Landlord with respect to any claim, liability, loss, cost or
expense due, in whole or in part, to Tenant's negligent acts or omissions or
willful misconduct.

16.04  WAIVER OF SUBROGATION

     (a)  Landlord agrees that, if obtainable at no, or minimal, additional
cost, and so long as the same is permitted under the laws of the State of
Illinois, it will include in its "All Risks" policies appropriate clauses
pursuant to which the insurance companies (i) waive all right of subrogation
against Tenant with respect to losses payable under such policies and/or (ii)
agree that such policies shall not be invalidated should the insured waive in
writing prior to a loss any or all right of recovery against any party for
losses covered by such policies.

                                       35
<PAGE>

     (b)  Tenant agrees to include, if obtainable at no, or minimal, additional
cost, and so long as the same is permitted under the laws of the State of
Illinois, in its "All Risks" insurance policy or policies on its furniture,
furnishings, fixtures and other property removable by Tenant under the
provisions of this Lease appropriate clauses pursuant to which the insurance
company or companies (i) waive the right of subrogation against Landlord and/or
any tenant of space in the Building with respect to losses payable under such
policy or policies and/or (ii) agree that such policy or policies shall not be
invalidated should the insured waive in writing prior to a loss any or all right
of recovery against any party for losses covered by such policy or policies. If
Tenant is unable to obtain in such policy or policies either of the clauses
described in the preceding sentence, Tenant shall, if legally possible and
without necessitating a change in insurance carriers, have Landlord named in
such policy or policies as an additional insured. If Landlord shall be named as
an additional insured in accordance with the foregoing, Landlord agrees to
endorse promptly to the order of Tenant, without recourse, any check, draft, or
order for the payment of money representing the proceeds of any such policy or
representing any other payment growing out of or connected with said policies,
and Landlord does hereby irrevocably waive any and all rights in and to such
proceeds and payments.

     (c)  Provided that Landlord's right of full recovery under its policy or
policies aforesaid is not adversely affected or prejudiced thereby, Landlord
hereby waives any and all right of recovery which it might otherwise have
against Tenant, its servants, agents and employees, for loss or damage occurring
to the Building and the fixtures, appurtenances and equipment therein, to the
extent the same is covered by Landlord's insurance, notwithstanding that such
loss or damage may result from the negligence or fault of Tenant, its servants,
agents or employees. Provided that Tenant's right of full recovery under its
aforesaid policy or policies is not adversely affected or prejudiced thereby,
Tenant hereby waives any and all right of recovery which it might otherwise have
against Landlord, its servants, and employees and against every other tenant in
the Building who shall have executed a similar waiver as set forth in this
Section 16.04 (c) for loss or damage to Tenant's furniture, furnishings,
fixtures and other property removable by Tenant under the provisions hereof to
the extent that same is covered or coverable by Tenant's insurance required
under this Lease, notwithstanding that such loss or damage may result from the
negligence or fault of Landlord, its servants, agents or employees, or such
other tenant and the servants, agents or employees thereof.

     (d)  Landlord and Tenant hereby agree to advise the other promptly if the
clauses to be included in their respective insurance policies pursuant to
subparagraphs (a) and (b) above cannot be obtained on the terms hereinbefore
provided and thereafter to furnish the other with a certificate of insurance or
copy of such policies showing the naming of the other as an additional insured,
as aforesaid. Landlord and Tenant hereby also agree to notify the other promptly
of any cancellation or change of the terms of any such policy which would affect
such clauses or naming. All such policies which name both Landlord and Tenant as
additional insureds shall, to the extent obtainable, contain agreements by the
insurers to the effect that no act or omission of any additional insured will
invalidate the policy as to the other additional insureds.

                                       36
<PAGE>

16.05  NOTICE OF CASUALTY

Tenant shall give Landlord notice in case of a fire or accident in the Premises
promptly after Tenant is aware of such event.

16.06  SELF INSURANCE

Notwithstanding the foregoing, upon approval by Landlord as hereinafter
provided, Tenant may elect to effect the foregoing insurance coverage, with
respect to casualty losses only, through a plan of self insurance. If Tenant
desires to effect any of the foregoing insurance coverage through a plan of self
insurance or any amendment to a plan of self insurance theretofore approved by
Landlord, Tenant shall deliver to Landlord a written notice of Tenant's desire
to self insure, which notice shall specify the risks and amounts Tenant desires
to self insure. Such notice shall be accompanied by audited financial statements
of Tenant and such other financial and other supporting documentation as
Landlord may reasonably require. Landlord shall approve or disapprove of such
plan of self insurance or proposed amendment thereto within thirty (30) days
after receipt of Tenant's notice and all financial and other supporting
documentation required hereby. Such approval shall not be arbitrarily withheld.
If Landlord approves such plan of self insurance and for so long as Tenant is
self insured, Tenant shall deliver to Landlord annual audited financial
statements and such other updated and supplemental information as Landlord may
reasonably require as a condition to the continuance of such plan of self
insurance. Landlord may at any time disapprove continuance of the plan of self
insurance, provided such disapproval is not arbitrary, in which event Tenant
shall promptly provide insurance coverage as required under Section 16.01 hereof
and such self insurance shall remain in effect until Tenant provides such
insurance. The rights contained in this Section 16.06 are personal to Tenant and
its Affiliates and shall not and may not be exercised by or for the benefit of
any other party.

     In the event Tenant elects to so self insure, Tenant agrees to indemnify,
protect, defend and hold the Indemnitees harmless against any and all actions,
claims, demands, costs and expenses, including reasonable attorney's fees and
expenses for defense thereof, arising from any circumstances that would
otherwise be covered by insurance if Tenant was carrying the types and amounts
of insurance required of Tenant under this Article Sixteen. In case of any
action or proceeding brought against the Indemnitees by reason of any such
claim, upon notice from Landlord, Tenant covenants to defend such action or
proceeding by counsel reasonably satisfactory to Landlord.

                               ARTICLE SEVENTEEN
                             INTENTIONALLY OMITTED

                                       37
<PAGE>

                               ARTICLE EIGHTEEN
                             RULES AND REGULATIONS

18.01  RULES

Tenant agrees for itself and for its subtenants, employees, agents, and invitees
to comply with the rules and regulations listed on Exhibit C attached hereto and
                                                   ---------
with all reasonable modifications and additions thereto which Landlord may make
from time to time.  In the event of any conflict between the rules and
regulations set forth on Exhibit C and the other provisions of this Lease, the
                         ---------
provisions of this Lease shall control.

18.02  ENFORCEMENT

Nothing in this Lease shall be construed to impose upon the Landlord any duty or
obligation to enforce the rules and regulations as set forth on Exhibit C or as
                                                                ---------
hereafter adopted, or the terms, covenants or conditions of any other lease as
against any other tenant, and the Landlord shall not be liable to the Tenant for
violation of the same by any other tenant, its servants, employees, agents,
visitors or licensees.  Landlord shall use reasonable efforts to enforce the
rules and regulations of the Building in a uniform and non-discriminatory
manner.  Tenant shall pay to Landlord all damages caused by Tenant's failure to
comply with the provisions of this Article Eighteen and shall also pay to
Landlord as additional Rent an amount equal to any increase in insurance
premiums directly attributable to such failure to comply.

                               ARTICLE NINETEEN
                          LANDLORD'S RESERVED RIGHTS

Landlord shall have the following rights exercisable without notice to Tenant
and without liability to Tenant for damage or injury to persons, property or
business and without being deemed an eviction or disturbance of Tenant's use or
possession of the Premises or giving rise to any claim for offset or abatement
of Rent: (1) to change the Building's name or street address upon thirty (30)
days' prior written notice to Tenant; (2) to install, affix and maintain all
signs on the exterior and/or interior of the Building, subject to Tenant's
rights as set forth in Article Thirty-Two hereof; (3) to designate and/or
approve prior to installation, all types of signs, window shades, blinds,
drapes, awnings or other similar items, and all internal lighting that may be
visible from the exterior of the Premises; (4) upon reasonable notice to Tenant
and in accordance with the provisions of Section 7.02 of this Lease, to display
the Premises to prospective purchasers at reasonable hours at any time during
the Term and to prospective tenants at reasonable hours during the last twelve
(12) months of the Term; (5) to grant to any party the exclusive right to
conduct any business or render any service (except as provided in Article Six of
this Lease) in or to the Building, provided such exclusive right shall not
operate to prohibit Tenant from using the Premises for the purpose permitted
hereunder; (6) to change the arrangement and/or location of entrances or
passageways, doors and doorways, corridors, elevators, stairs, washrooms or
public portions of the Building, and to close entrances, doors, corridors,
elevators or other facilities, provided that such action shall not materially
and adversely interfere with Tenant's access to the Premises or the Building;
(7) to have access for Landlord and other tenants of the Building to any mail
chutes and boxes located in or on the Premises as required by any applicable
rules of the United States Post Office; and (8) to close

                                       38
<PAGE>

the Building after Standard Operating Hours, except that Tenant and its
employees and invitees shall be entitled to admission to the Building and the
Premises 24 hours per day, 7 days per week, under such regulations as Landlord
prescribes for security purposes.

                                ARTICLE TWENTY
                             ESTOPPEL CERTIFICATE

20.01  IN GENERAL

Within fifteen (15) days after request therefor by Landlord, Mortgagee or any
prospective mortgagee or owner, Tenant agrees as directed in such request to
execute an Estoppel Certificate in recordable form, binding upon Tenant,
certifying (i) that this Lease is unmodified and in full force and effect (or if
there have been modifications, a description of such modifications and that this
Lease as modified is in full force and effect); (ii) the dates to which Rent has
been paid; (iii) that Tenant is in the possession of the Premises if that is the
case; (iv) that, to Tenant's knowledge, Landlord is not in default under this
Lease, or, if Tenant believes Landlord is in default, the nature thereof in
detail; (v) that, to Tenant's knowledge, Tenant has no off-sets or defenses to
the performance of its obligations under this Lease (except as set forth in the
Lease)(or if Tenant believes there are any off-sets or defenses (other than as
set forth in the Lease), a full and complete explanation thereof); (vi) that the
Premises have been completed in accordance with the terms and provisions hereof
or the Workletter, that Tenant has accepted the Premises and the condition
thereof and of all improvements thereto and, to Tenant's knowledge, Tenant has
no claims against Landlord or any other party with respect thereto (or if any
items are not completed or if Tenant has not accepted possession or has claims,
an explanation of the same); (vii) that if an assignment of rents or leases has
been served upon the Tenant by a Mortgagee, Tenant will acknowledge receipt
thereof and agree to be bound by the provisions thereof; (viii) that Tenant will
give to the Mortgagee copies of all notices required or permitted to be given by
Tenant to Landlord; and (ix) to any other information reasonably requested
related to the status of the Lease.

20.02  ENFORCEMENT

In the event that Tenant fails to deliver an Estoppel Certificate, then such
failure shall be a Default for which there shall be no cure or grace period.
Further, if Tenant so fails to deliver the Estoppel Certificate, Landlord and
any lender, prospective lender, investor, or purchaser may conclusively presume
and rely, except as otherwise represented by Landlord, (i) that the terms and
provisions of this Lease have not been changed; (ii) that this Lease has not
been cancelled or terminated; (iii) that not more than one month's Rent has been
paid in advance; and (iv) that Landlord is not in default in the performance of
any of its obligations under this Lease. In such event, Tenant is estopped from
denying the truth of such facts.

                              ARTICLE TWENTY-ONE
                             INTENTIONALLY OMITTED

                                       39
<PAGE>

                              ARTICLE TWENTY-TWO
                              REAL ESTATE BROKERS

Landlord and Tenant each hereby represent to the other that, except for CB
Richard Ellis and Staubach Midwest LLC (the "Brokers"), neither party has dealt
with any real estate broker, sales person, or finder in connection with this
Lease, and no such person initiated or participated in the negotiation of this
Lease, or showed the Premises to Tenant. Tenant hereby agrees to indemnify,
protect, defend and hold Landlord and the Indemnitees, harmless from and against
any and all liabilities and claims for commissions and fees arising out of a
breach of the foregoing representation and Landlord hereby agrees to indemnify,
protect, defend and hold Tenant harmless from and against any and all
liabilities and claims for commissions and fees made by the Brokers arising out
of a breach of the foregoing representation. Landlord shall be responsible for
the payment of all commissions to the Brokers specified in this Article.

                             ARTICLE TWENTY-THREE
                             MORTGAGEE PROTECTION

23.01  SUBORDINATION AND ATTORNMENT

This Lease is and shall be expressly subject and subordinate at all times to (i)
any ground or underlying lease of the Real Property, now or hereafter existing,
and all amendments, extensions, renewals and modifications to any such lease,
and (ii) the lien of any first mortgage or trust deed now or hereafter
encumbering fee title to the Real Property and/or the leasehold estate under any
such lease, and all amendments, extensions, renewals, replacements and
modifications of such mortgage or trust deed and/or the obligation secured
thereby, unless such ground lease or ground lessor, or mortgage, trust deed or
Mortgagee, expressly provides or elects that the Lease shall be superior to such
lease or mortgage or trust deed, it being understood that currently there is no
mortgage, ground lease or trust deed encumbering the Real Property. If any such
mortgage or trust deed is foreclosed (including any sale of the Real Property
pursuant to a power of sale), or if any such lease is terminated, upon request
of the Mortgagee or ground lessor, as the case may be, Tenant shall attorn to
the purchaser at the foreclosure sale or to the ground lessor under such lease,
as the case may be, provided that such successor agrees not to disturb Tenant in
its use and quiet enjoyment of the Premises so long as Tenant (i) is not in
Default under the Lease, and (ii) Tenant and/or an Affiliate occupies no less
than 79,097 rentable square feet in the Building; and further provided that such
successor shall not be (1) bound by any payment of Rent for more than one month
in advance except payments in the nature of security for the performance by
Tenant of its obligations under this Lease; or (2) subject to any offsets,
defenses or damages arising out of a default of any obligations of any preceding
Landlord, except those which are continuing as of the date such purchaser
succeeds to Landlord's interest; or (3) bound by any amendment or modification
of this Lease made without the written consent of the Mortgagee or ground lessor
to the extent such consent is required by the terms of the mortgage, trust deed
or ground lease and excluding the exercise of any options or elections contained
in the Lease, including without limitation, options to renew the term, expand
the Premises, rights of first offer, termination and contraction; or (4) liable
for any security deposits not actually received in cash by such purchaser or
ground lessor. This subordination shall be self-operative and no further
certificate or instrument of subordination need be required by any such
Mortgagee or ground lessor. In

                                       40
<PAGE>

confirmation of such subordination, however, Tenant shall execute any reasonable
certificate or instrument that Landlord, Mortgagee or ground lessor may request,
so long as such instrument contains a non-disturbance provision reasonably
acceptable to Tenant, within twenty (20) days of a request to do so. If Tenant
fails to deliver such certificate or instrument within said twenty-(20) day
period, such failure shall be a Default hereunder.

23.02  MORTGAGEE PROTECTION

Tenant agrees to give any Mortgagee or ground lessor, concurrently, by
registered or certified mail, a copy of any notice of default served upon the
Landlord by Tenant, provided that prior to such notice Tenant has received
written notice (by way of service on Tenant of a copy of an assignment of rents
and leases, or otherwise) of the address of such Mortgagee or ground lessor.
Tenant further agrees that if Landlord shall have failed to cure such default
within the time provided for in this Lease, then the Mortgagee or ground lessor
shall have an additional thirty (30) days after receipt of notice thereof within
which to cure such default or if such default cannot be cured within that time,
then if the Mortgagee or ground lessor agrees to cure such default, then the
Mortgagee or ground lessor shall have such additional time as may be necessary,
if, within such thirty (30) days, any Mortgagee or ground lessor has commenced
and is diligently pursuing the remedies necessary to cure such default, but in
no event shall said thirty (30) day period be extended by more than forty-five
(45) days. Such period of time shall be extended by any period within which such
Mortgagee or ground lessor is prevented from commencing or pursuing such
foreclosure proceedings or other proceedings to acquire possession of the Real
Property by reason of Landlord's bankruptcy. Until the time allowed as aforesaid
for Mortgagee or ground lessor to cure such defaults has expired without cure,
Tenant shall have no right to, and shall not, terminate this Lease on account of
default. This Lease may not be modified or amended so as to reduce the rent or
shorten the term, or so as to adversely affect in any other respect to any
material extent the rights of the Landlord, nor shall this Lease be canceled or
surrendered, without the prior written consent, in each instance, of the ground
lessor or the Mortgagee.

                              ARTICLE TWENTY-FOUR
                                    NOTICES

     (a)  All notices, demands or requests provided for or permitted to be given
pursuant to this Lease must be in writing and shall be personally delivered,
sent by Federal Express or other overnight courier service, or mailed by first
class, registered or certified mail, return receipt requested, postage prepaid.

     (b)  All notices, demands or requests to be sent pursuant to this Lease
shall be deemed to have been properly given or served by delivering or sending
the same in accordance with this Section, addressed to the parties hereto at
their respective addresses listed below:

          (1)  Notices to Landlord shall be addressed:

               c/o CB Richard Ellis, Inc.
               10 South LaSalle Street, Suite 1301
               Chicago, Illinois 60603
               Attention:  General Manager

                                       41
<PAGE>

          with a copy to the following:

               Metropolitan Life Insurance Company
               2001 Spring Road, Suite 400
               Oak Brook, Illinois 60523
               Attention:  Vice President
               Real Estate Investments

          (2)  Notices to Tenant shall be addressed:

               The Northern Trust Company
               50 South LaSalle Street
               Chicago, Illinois 60675
               Attention:  Vice President Corporate Real Estate

          with a copy to the following:

               The Northern Trust Company
               20 South LaSalle Street
               Chicago, Illinois 60675
               Attention:  General Counsel

     (c)  If notices, demands or requests are sent by registered or certified
mail, said notices, demands or requests shall be effective upon being deposited
in the United States mail. However, the time period in which a response to any
such notice, demand or request must be given shall commence to run from the date
of receipt on the return receipt of the notice, demand or request by the
addressee thereof. Rejection or other refusal to accept or the inability to
deliver because of changed address of which no notice was given shall be deemed
to be receipt of notice, demand or request sent.

     Notices may also be served by personal service upon any officer, director
or partner of Landlord or Tenant or in the case of delivery by Federal Express
or other overnight courier service, notices shall be effective upon acceptance
of delivery by an employee, officer, director or partner of Landlord or Tenant.

     (d)  By giving to the other party at least thirty (30) days written notice
thereof, either party shall have the right from time to time during the term of
this Lease to change their respective addresses for notices, statements, demands
and requests, provided such new address shall be within the United States of
America.

                              ARTICLE TWENTY-FIVE
                                RENEWAL OPTIONS

     (a)  Tenant shall have and is hereby granted an option (the "First Renewal
Option") to extend the term of this Lease from January 1, 2016 to December 31,
2020 (the "First Renewal Term"), on all the terms, covenants and conditions of
this Lease, except that the rental shall be as

                                       42
<PAGE>

set forth below. To exercise the First Renewal Option, Tenant shall notify
Landlord in writing not later than June 30, 2014 ("Tenant's First Notice"). If
Tenant exercises the First Renewal Option, then the word "Term" as used in this
Lease shall be deemed to include the First Renewal Term.

     (b)  The Monthly Base Rent during the First Renewal Term shall be equal to
the Market Rate (as defined in Section 25(s) hereof) multiplied by the Rentable
Area of the Premises.

     (c)  Landlord shall respond to Tenant's First Notice with its determination
of Market Rate within thirty (30) days of receipt of Tenant's First Notice.
Tenant shall have thirty (30) days after receipt of Landlord's determination to
accept, reject or submit for arbitration (as outlined in Article Twenty-Six
below). If Tenant elects to submit to arbitration, Tenant shall name its
arbitrator in its notice to Landlord that it has selected arbitration.

     (d)  It shall be a condition to Tenant's exercise of the First Renewal
Option that both at the time of delivery of Tenant's First Notice and at the
commencement of the First Renewal Term: (i) Tenant is not in Default under this
Lease, and (ii) except as may be permitted below, Tenant and/or an Affiliate is
occupying the Premises for the conduct of business. Any termination of this
Lease or termination of Tenant's right of possession shall terminate all of
Tenant's rights to the First Renewal Option. Except as set forth below, the
First Renewal Option may be exercised only by and is personal to Tenant and/or
an Affiliate and may not be exercised by or for the benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise the First Renewal Option shall not be affected by any
sublease of the Premises entered into pursuant to the terms of this Lease, but
in no event shall any sublessee have any rights to exercise said First Renewal
Option. In addition, the right to exercise the First Renewal Option shall be
automatically transferred to (i) an Assignee who leases the entire Premises
pursuant to the terms of this Lease or (ii) to any Assignee pursuant to an
Assignment of this Lease for more than 25% of Tenant's then leased space in the
Building, but shall not be transferred to any Assignee pursuant to an Assignment
of this Lease for less than 25% of Tenant's then leased space in the Building.

     (e)  Landlord shall have no obligation to make improvements, decorations,
repairs, alterations or additions to the Premises as a condition to Tenant's
obligations to pay Rent for the First Renewal Term except as may be determined
as part of Market Rate.

     (f)  In the event that Tenant exercises the First Renewal Option, Tenant
agrees to enter into an amendment to this Lease reasonably acceptable to Tenant
incorporating the First Renewal Term and Monthly Base Rent applicable to such
option the earlier of (i) sixty (60) days following the exercise of the First
Renewal Option or (ii) thirty (30) days following the delivery of the
arbitrator's decision to the parties pursuant to the terms of Article Twenty-Six
of this Lease.

     (g)  Tenant shall also have and is hereby granted a second option (the
"Second Renewal Option") to extend the term of this Lease from January 1, 2021
to December 31, 2025 (the "Second Renewal Term"), on all the terms, covenants
and conditions of this Lease, except that the rental shall be as set forth
below. To exercise the Second Renewal Option, Tenant shall notify Landlord

                                       43
<PAGE>

in writing not later than June 30, 2019 ("Tenant's Second Notice"). If Tenant
exercises the Second Renewal Option, then the word "Term" as used in this Lease
shall be deemed to include the Second Renewal Term.

     (h)  The Monthly Base Rent during the Second Renewal Term shall be equal to
the Market Rate (as defined in Section 25(s) hereof) multiplied by the Rentable
Area of the Premises.

     (i)  Landlord shall respond to Tenant's Second Notice with its
determination of Market Rate within thirty (30) days of receipt of said Notice.
Tenant shall have thirty (30) days after receipt of Landlord's determination to
accept, reject or submit for arbitration (as outlined in Article Twenty-Six
below). If Tenant elects to submit to arbitration, Tenant shall name its
arbitrator in its notice to Landlord that it has selected arbitration.

     (j)  It shall be a condition to Tenant's exercise of the Second Renewal
Option that both at the time of delivery of Tenant's Second Notice and at the
commencement of the Second Renewal Term: (i) Tenant is not in Default under this
Lease, and (ii) except as may be permitted below, Tenant and/or an Affiliate is
occupying the Premises for the conduct of business. Any termination of this
Lease or termination of Tenant's right of possession shall terminate all of
Tenant's rights to the Second Renewal Option. Except as set forth below, the
Second Renewal Option may be exercised only by and is personal to Tenant and/or
an Affiliate and may not be exercised by or for the benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise the Second Renewal Option shall not be affected by any
sublease of the Premises entered into pursuant to the terms of this Lease, but
in no event shall any sublessee have any rights to exercise said Second Renewal
Option. In addition, the right to exercise the Second Renewal Option shall be
automatically transferred to (i) an Assignee who leases the entire Premises
pursuant to the terms of this Lease or (ii) to any Assignee pursuant to an
Assignment of this Lease for more than 25% of Tenant's then leased space in the
Building, but shall not be transferred to any Assignee pursuant to an Assignment
of this Lease for less than 25% of Tenant's then leased space in the Building.

     (k)  Landlord shall have no obligation to make improvements, decorations,
repairs, alterations or additions to the Premises as a condition to Tenant's
obligations to pay Rent for the Second Renewal Term except as may be determined
as part of Market Rate.

     (l)  In the event that Tenant exercises the Second Renewal Option, Tenant
agrees to enter into an amendment to this Lease reasonably acceptable to Tenant
incorporating the Second Renewal Term and Monthly Base Rent applicable to such
option (i) sixty (60) days following the exercise of the Second Renewal Option
or (ii) thirty (30) days following the delivery of the arbitrator's decision to
the parties pursuant to the terms of Article Twenty-Six of this Lease.

     (m)  Tenant shall also have and is hereby granted a third option (the
"Third Renewal Option") to extend the term of this Lease from January 1, 2026 to
December 31, 2030 (the "Third Renewal Term"), on all the terms, covenants and
conditions of this Lease, except that the rental shall be as set forth below,
and no additional renewal rights are granted Tenant beyond the Third

                                       44
<PAGE>

Renewal Term. To exercise the Third Renewal Option, Tenant shall notify Landlord
in writing not later than June 30, 2024 ("Tenant's Third Notice"). If Tenant
exercises the Third Renewal Option, then the word "Term" as used in this Lease
shall be deemed to include the Third Renewal Term.

     (n)  The Monthly Base Rent during the Third Renewal Term shall be equal to
the Market Rate (as defined in Section 25(s) hereof) multiplied by the Rentable
Area of the Premises.

     (o)  Landlord shall respond to Tenant's Third Notice with its determination
of Market Rate within thirty (30) days of receipt of said Notice.  Tenant shall
have thirty (30) days after receipt of Landlord's determination to accept,
reject or submit for arbitration (as outlined in Article Twenty-Six below).  If
Tenant elects to submit to arbitration, Tenant shall name its arbitrator in its
notice to Landlord that it has selected arbitration.

     (p)  It shall be a condition to Tenant's exercise of the Third Renewal
Option that both at the time of delivery of Tenant's Third Notice and at the
commencement of the Third Renewal Term: (i) Tenant is not in Default under this
Lease, and (ii) except as may be permitted below, Tenant and/or an Affiliate is
occupying the Premises for the conduct of business.  Any termination of this
Lease or termination of Tenant's right of possession shall terminate all of
Tenant's rights to the Third Renewal Option.  Except as set forth below, the
Third Renewal Option may be exercised only by and is personal to Tenant and/or
an Affiliate and may not be exercised by or for the benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise the Third Renewal Option shall not be affected by any
sublease of the Premises entered into pursuant to the terms of this Lease, but
in no event shall any sublessee have any rights to exercise said Third Renewal
Option.  In addition, the right to exercise the Third Renewal Option shall be
automatically transferred to (i) an Assignee who leases the entire Premises
pursuant to the terms of this Lease or (ii) to any Assignee pursuant to an
Assignment of this Lease for more than 25% of Tenant's then leased space in the
Building, but shall not be transferred to any Assignee pursuant to an Assignment
of this Lease for less than 25% of Tenant's then leased space in the Building.

     (q)  Landlord shall have no obligation to make improvements, decorations,
repairs, alterations or additions to the Premises as a condition to Tenant's
obligations to pay Rent for the Third Renewal Term except as may be determined
as part of Market Rate.

     (r)  In the event that Tenant exercises the Third Renewal Option, Tenant
agrees to enter into an amendment to this Lease reasonably acceptable to Tenant
incorporating the Third Renewal Term and Monthly Base Rent applicable to such
option within (i) sixty (60) days following the exercise of the Third Renewal
Option or (ii) thirty (30) days following the delivery of the arbitrator's
decision to the parties pursuant to the terms of Article Twenty-Six of this
Lease.

     (s)  The "Market Rate" shall mean a base net rent annual amount per
rentable square foot and other rental charges for the lease term equivalent to
the period for which the Market Rate is being determined beginning the first
(1/st/) day of the subject period that a willing, credit-worthy non-equity
tenant renewing space comparable to the Premises would pay and a willing
Landlord of an

                                       45
<PAGE>

office building comparable to the Building in the Chicago West/Central Loop
office market (the "Market") would accept at arms length. Appropriate
consideration will be given to base net rent, rent escalations, tenant
concessions (e.g. free rent, tenant improvements and other cash allowances),
length of term, size and location of the premises being leased, tenant
improvement allowances, brokerage commissions and other generally applicable
terms and conditions prevailing for comparable space in comparable buildings
located in the Market, as evidenced by then recently completed renewals within
the Market.

                              ARTICLE TWENTY-SIX
                                  ARBITRATION

     (a)  If Tenant has elected to arbitrate in accordance with Article Twenty-
Five above or Articles Twenty-Seven, Twenty-Eight or Twenty-Nine below, then
Landlord shall have thirty (30) days to select its arbitrator. The arbitrator
selected by each of Landlord and Tenant shall, by profession, be a real estate
appraiser (with the professional designation of M.A.I. or, if M.A.I. ceases to
exist, a comparable designation from an equivalent professional appraisal
organization) who shall have been active over the five (5) year period ending on
the date of such appointment in appraisal of commercial properties in the
Chicago downtown business area. The determination of the arbitrators shall be
limited solely to the issue of whether Landlord's or Tenant's submitted Market
Rate for the Premises is the closest to the Market Rate for the Premises as
determined by the arbitrators, taking into account all relevant elements.

     (b)  The two arbitrators so appointed shall, within ten (10) days of the
date of the appointment of the last appointed arbitrator, agree upon and appoint
a third arbitrator who shall be qualified under the same criteria set forth
hereinabove for qualification of the initial two arbitrators.

     (c)  The three arbitrators shall, within thirty (30) days of the
appointment of the third arbitrator, reach a decision as to whether the parties
shall use Landlord's or Tenant's submitted Market Rate, and shall notify
Landlord and Tenant thereof in writing.

     (d)  The decision of the majority of the three arbitrators shall be binding
upon Landlord and Tenant and judgment upon such decision may be entered in by
any court having jurisdiction over Landlord and Tenant.

     (e)  If the two arbitrators fail to agree upon and appoint a third
arbitrator, both arbitrators shall be dismissed and Landlord and Tenant each
shall promptly select and appoint one new arbitrator each possessing the
qualifications described in clause (a) of this Article Twenty-Six. Such new
arbitrators shall promptly follow the procedure outlined in clauses (b) and (c)
of this Article Twenty-Six.

     (f)  The cost of arbitration shall be paid by Landlord if Tenant's
submitted Market Rate is selected and by Tenant if Landlord's submitted Market
Rate is selected.

     (g)  Notwithstanding the foregoing, if either Landlord or Tenant fails to
appoint an arbitrator within the time periods provided for herein and such
failure to appoint an arbitrator is not cured within ten (10) days after receipt
by such failing party of written demand to do so by the other

                                       46
<PAGE>

party (which other party shall have appointed its arbitrator prior to sending
such written demand), then the arbitrator appointed by the party sending such
demand, acting alone, shall reach a decision on the applicable Market Rate,
notify Landlord and Tenant in writing thereof, and such arbitrator's decision
shall be binding on Landlord and Tenant.

                             ARTICLE TWENTY-SEVEN
                               EXPANSION OPTIONS

     (a)  Tenant shall have the right to lease additional space with a lease
commencement date of September 1, 2001 (the "2001 Expansion Option") consisting
of 20,722 rentable square feet of space located in the "Low Rise" (floors 3 -
13) portion of the Building (the "2001 Expansion Space") on the terms and
conditions set forth herein. Landlord shall give Tenant notice upon full
execution of this Lease (the "2001 Landlord's Notice Date") with respect to the
space available, including detailed existing condition plans, if available. To
exercise the 2001 Expansion Option, Tenant shall notify Landlord in writing
("Tenant's 2001 Expansion Notice") on or before January 1, 2001.  Tenant's
possession date (the "2001 Possession Date") shall be June 1, 2001.  The 2001
Expansion Space shall be delivered to Tenant on the 2001 Possession Date in its
then current, AS IS condition, except with respect to the conditions set forth
in Exhibit F - Base Building Conditions, and Landlord has no obligation to make
   ---------
any improvement to the 2001 Expansion Space, provided however, that Landlord
shall contribute an amount (the "2001Contribution") equal to Five Hundred
Ninety-Four Thousand Ninety-Nine and 74/100 Dollars ($594,099.74)(based on
$28.67 per rentable square foot) to be applied to Tenant's completion of such
improvements and additions to the 2001 Expansion Space as Tenant deems desirable
including all construction improvements, architectural and engineering fees,
third party construction consultants, FF&E expenses, or teledata related costs
(the "2001 Work").  Tenant shall complete the 2001 Work in accordance with the
terms of this Lease, including, without limitation, Exhibit B. If the costs of
                                                    ---------
completing the 2001 Work exceeds the sum of  the 2001 Contribution, Tenant shall
pay all such costs. In the event that Tenant fails to use all of the 2001
Contribution as set forth above within the first twelve (12) months after the
2001 Possession Date, then the portion of the 2001 Contribution which is not
disbursed as provided above shall be applied against installments of Rent next
due from Tenant.

     (b)  Monthly Base Rent for the 2001 Expansion Space (the "2001 Expansion
Base Rent") shall be equal to the then-escalated Monthly Base Rent rate for the
Premises and shall commence September 1, 2001 (the "2001 Lease Commencement
Date").

     (c)  Tenant shall have the right to lease additional space with a lease
commencement date in 2004 (the "2004 Expansion Option") consisting of between
4,500 and 7,100 rentable square feet of space (as currently determined, but
which square footage amounts may be modified by the provisions of Section 2.04
of this Lease) located in the Low Rise portion of the Building (the "2004
Expansion Space") on the terms and conditions set forth herein. Landlord shall
give Tenant notice between March 1, 2003 and February 28, 2004 (the "2004
Landlord's Notice Date") with respect to the space available, including detailed
existing condition plans, if available. To exercise the 2004 Expansion Option,
Tenant shall notify Landlord in writing ("Tenant's 2004 Expansion Notice")
within thirty (30) days of receipt of the 2004 Landlord's Notice. Tenant's
possession date (the "2004 Possession Date") shall be as stated in the 2004
Landlord's Notice, but in no event shall the

                                       47
<PAGE>

2004 Possession Date be earlier than eight (8) months after the date of the 2004
Landlord's Notice. The 2004 Expansion Space shall be delivered to Tenant on the
2004 Possession Date in its then current, AS IS condition, except with respect
to the conditions set forth in Exhibit F - Base Building Conditions, and
                               ---------
Landlord has no obligation to make any improvement to the 2004 Expansion Space,
provided however, that Landlord shall contribute an amount (the "2004
Contribution") equal to of $30.00/rentable square foot, declining on a monthly
basis proportional to time remaining on the term (i.e. If the term for the 2004
Expansion Space is for 12 years, the 2004 Contribution shall be $24.00/rentable
square foot). The 2004 Contribution is to be applied to Tenant's completion of
such improvements and additions to the 2004 Expansion Space as Tenant deems
desirable including all construction improvements, architectural and engineering
fees, third party construction consultants, FF&E expenses, or teledata related
costs (the "2004 Work"). Tenant shall complete the 2004 Work in accordance with
the terms of this Lease, including, without limitation, Exhibit B. If the costs
                                                        ---------
of completing the 2004 Work exceeds the sum of the 2004 Contribution, Tenant
shall pay all such costs. In the event that Tenant fails to use all of the 2004
Contribution as set forth above within the first twelve (12) months after the
2004 Possession Date, then the portion of the 2004 Contribution which is not
disbursed as provided above shall be applied against installments of Rent next
due from Tenant.

     (d)  Monthly Base Rent for the 2004 Expansion Space (the "2004 Expansion
Base Rent") shall be equal to the then-escalated Monthly Base Rent rate for the
Premises and shall commence ninety (90) days after the 2004 Possession Date (the
"2004 Lease Commencement Date").

     (e)  Tenant shall have the right to lease additional space with a lease
commencement date in 2005 (the "2005 Expansion Option") consisting of between
8,500 and 14,900 rentable square feet of space (as currently determined, but
which square footage amounts may be modified by the provisions of Section 2.04
of this Lease) located in the Low Rise portion of the Building (the "2005
Expansion Space") on the terms and conditions set forth herein. Landlord shall
give Tenant notice between March 1, 2004 and February 28, 2005 (the "2005
Landlord's Notice Date") with respect to the space available, including detailed
existing condition plans, if available. To exercise the 2005 Expansion Option,
Tenant shall notify Landlord in writing ("Tenant's 2005 Expansion Notice")
within thirty (30) days of receipt of the 2005 Landlord's Notice.  Tenant's
possession date (the "2005 Possession Date") shall be as stated in the 2005
Landlord's Notice, but in no event shall the 2005 Possession Date be earlier
than eight (8) months after the date of the 2005 Landlord's Notice.  The 2005
Expansion Space shall be delivered to Tenant on the 2005 Possession Date in its
then current, AS IS condition, except with respect to the conditions set forth
in Exhibit F - Base Building Conditions, and Landlord has no obligation to make
   ---------
any improvement to the 2005 Expansion Space, provided however, that Landlord
shall contribute an amount (the "2005 Contribution") equal to of $30.00/rentable
square foot, declining on a monthly basis proportional to time remaining on the
term (i.e. If the term for the 2005 Expansion Space is for 10 years, the 2005
Contribution shall be $20.00/rentable square foot). The 2005 Contribution is to
be applied to Tenant's completion of such improvements and additions to the 2005
Expansion Space as Tenant deems desirable including all construction
improvements, architectural and engineering fees, third party construction
consultants, FF&E expenses, or teledata related costs (the "2005 Work").  Tenant
shall complete the 2005 Work in accordance with the terms of this Lease,
including, without limitation, Exhibit B. If the costs of completing the 2005
                               ---------
Work exceeds the sum

                                       48
<PAGE>

of the 2005 Contribution, Tenant shall pay all such costs. In the event that
Tenant fails to use all of the 2005 Contribution as set forth above within the
first twelve (12) months after the 2005 Possession Date, then the portion of the
2005 Contribution which is not disbursed as provided above shall be applied
against installments of Rent next due from Tenant.

     (f)  Monthly Base Rent for the 2005 Expansion Space (the "2005 Expansion
Base Rent") shall be equal to the then-escalated Monthly Base Rent rate for the
Premises and shall commence ninety (90) days after the 2005 Possession Date (the
"2005 Lease Commencement Date").

     (g)  Tenant shall have the right to lease additional space with a lease
commencement date in 2007 (the "2007 Expansion Option") consisting of between
10,000 and 23,000 rentable square feet of space (as currently determined, but
which square footage amounts may be modified by the provisions of Section 2.04
of this Lease) located in the Low Rise portion of the Building (the "2007
Expansion Space") on the terms and conditions set forth herein. Landlord shall
give Tenant notice between March 1, 2006 and February 28, 2007 (the "2007
Landlord's Notice Date") with respect to the space available, including detailed
existing condition plans, if available. To exercise the 2007 Expansion Option,
Tenant shall notify Landlord in writing ("Tenant's 2007 Expansion Notice")
within thirty (30) days of receipt of the 2007 Landlord's Notice.  Tenant's
possession date (the "2007 Possession Date") shall be as stated in the 2007
Landlord's Notice, but in no event shall the 2007 Possession Date be earlier
than eight (8) months after the date of the 2007 Landlord's Notice.  The 2007
Expansion Space shall be delivered to Tenant on the 2007 Possession Date in its
then current, AS IS condition, except with respect to the conditions set forth
in Exhibit F - Base Building Conditions, and Landlord has no obligation to make
   ---------
any improvement to the 2007 Expansion Space, provided however, that Landlord may
contribute an amount (the "2007 Contribution") as determined in accordance with
the provisions of Section 25(s). The 2007 Contribution, if any, is to be applied
to Tenant's completion of such improvements and additions to the 2007 Expansion
Space as Tenant deems desirable including all construction improvements,
architectural and engineering fees, third party construction consultants, FF&E
expenses, or teledata related costs (the "2007 Work").  Tenant shall complete
the 2007 Work in accordance with the terms of this Lease, including, without
limitation, Exhibit B. If the costs of completing the 2007 Work exceeds the sum
            ---------
of  the 2007 Contribution, if any, Tenant shall pay all such costs. In the event
that Tenant fails to use all of the 2007 Contribution, if any, as set forth
above within the first twelve (12) months after the 2007 Possession Date, then
the portion of the 2007 Contribution, if any, which is not disbursed as provided
above shall be applied against installments of Rent next due from Tenant.

     (h)  Monthly Base Rent for the 2007 Expansion Space (the "2007 Expansion
Base Rent") shall be equal to the Market Rate as defined in Section 25(s) above
multiplied by the rentable area of the 2007 Expansion Space and shall commence
ninety (90) days after the 2007 Possession Date (the "2007 Lease Commencement
Date").

     (i)  Landlord shall include in the notice given on the "2007 Landlord's
Notice Date" its determination of Market Rate.  Tenant shall have thirty (30)
days after receipt of Landlord's determination to accept, reject or submit for
arbitration (as outlined in Article Twenty-Six above).

                                       49
<PAGE>

If Tenant elects to submit to arbitration, Tenant shall name its arbitrator in
its notice to Landlord that it has selected arbitration.

     (j)  Tenant shall have the right to lease additional space with a lease
commencement date in 2011 (the "2011 Expansion Option") consisting of one full
floor and approximately 21,000 rentable square feet of space (as currently
determined, but which square footage amounts may be modified by the provisions
of Section 2.04 of this Lease) located in the Building (the "2011 Expansion
Space") on the terms and conditions set forth herein.  Landlord shall give
Tenant notice between March 1, 2009 and February 28, 2010 (the "2011 Landlord's
Notice Date") with respect to the space available, including detailed existing
condition plans, if available. To exercise the 2011 Expansion Option, Tenant
shall notify Landlord in writing ("Tenant's 2011 Expansion Notice") within
thirty (30) days of receipt of the 2011 Landlord's Notice.  Tenant's possession
date (the "2011 Possession Date") shall be as stated in the 2011 Landlord's
Notice and shall occur between July 1, 2010 and June 30, 2011.  The 2011
Expansion Space shall be delivered to Tenant on the 2011 Possession Date in its
then current, AS IS condition, except with respect to the conditions set forth
in Exhibit F - Base Building Conditions, and Landlord has no obligation to make
   ---------
any improvement to the 2011 Expansion Space, provided however, that Landlord may
contribute an amount (the "2011 Contribution") as determined in accordance with
the provisions of Section 25(s). The 2011 Contribution, if any, is to be applied
to Tenant's completion of such improvements and additions to the 2011 Expansion
Space as Tenant deems desirable including all construction improvements,
architectural and engineering fees, third party construction consultants, FF&E
expenses, or teledata related costs (the "2011 Work").  Tenant shall complete
the 2011 Work in accordance with the terms of this Lease, including, without
limitation, Exhibit B. If the costs of completing the 2011 Work exceeds the sum
            ---------
of the 2011 Contribution, Tenant shall pay all such costs.  In the event that
Tenant fails to use all of the 2011 Contribution, if any, as set forth above
within the first twelve (12) months after the 2011 Possession Date, then the
portion of the 2011 Contribution, if any,  which is not disbursed as provided
above shall be applied against installments of Rent next due from Tenant.

     (k)  Monthly Base Rent for the 2011 Expansion Space (the "2011 Expansion
Base Rent") shall be equal to the Market Rate as defined in Section 25(s) above
multiplied by the rentable area of the 2011 Expansion Space and shall commence
ninety (90) days after the 2011 Possession Date (the "2011 Lease Commencement
Date").

     (l)  Landlord shall include in the notice given on the "2011 Landlord's
Notice Date" its determination of Market Rate.  Tenant shall have thirty (30)
days after receipt of Landlord's determination to accept, reject or submit for
arbitration (as outlined in Article Twenty-Six above).  If Tenant elects to
submit to arbitration, Tenant shall name its arbitrator in its notice to
Landlord that it has selected arbitration.

     (m)  The 2001 Expansion Option, the 2004 Expansion Option, the 2005
Expansion Option, the 2007 Expansion Option and the 2011 Expansion Option are
herein collectively referred to as the "Expansion Options".

     (n)  It shall be a condition to Tenant's exercise of any of the Expansion
Options that both at the time of delivery of Tenant's Expansion Notices and at
the commencement of the

                                       50
<PAGE>

Term with respect to any of the Expansion Options: (i) Tenant is not in Default
under this Lease, and (ii) except as may be permitted below, Tenant and/or an
Affiliate is occupying the Premises for the conduct of business. Any termination
of this Lease or termination of Tenant's right of possession shall terminate all
of Tenant's rights to any of the remaining Expansion Options. Except as set
forth below, all of the Expansion Options may be exercised only by and is
personal to Tenant and/or an Affiliate and may not be exercised by or for the
benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise any of the Expansion Options shall not be affected by any
sublease of the Premises entered into pursuant to the terms of this Lease, but
in no event shall any sublessee have any rights to exercise any of said
Expansion Options.  In addition, the right to exercise any of the Expansion
Options shall be automatically transferred to (i) an Assignee who leases the
entire Premises pursuant to the terms of this Lease or (ii) to any Assignee
pursuant to an Assignment of this Lease for more than 25% of Tenant's then
leased space in the Building, but shall not be transferred to any Assignee
pursuant to an Assignment of this Lease for less than 25% of Tenant's then
leased space in the Building.

     (o)  In the event that Tenant exercises any of the foregoing Expansion
Options, Tenant agrees to enter into an amendment to this Lease reasonably
acceptable to Tenant incorporating the applicable Expansion Space to the
Premises and making such other conforming changes as are necessary to the
computation of the Monthly Base Rent and the calculation of Tenant's Share
applicable to such option the earlier of (i) sixty (60) days following the
exercise of the any of the Expansion Options or (ii) thirty (30) days following
the delivery of the arbitrator's decision to the parties pursuant to the terms
of Article Twenty-Six of this Lease. The Expansion Option Spaces shall be leased
for their respective Terms upon the terms and conditions provided for in this
Lease, except for such changes as are required pursuant to the terms hereof,
which shall be as set forth in the Amendment described above.  If Tenant does
not execute and deliver the Amendment to this Lease to Landlord as set forth
above, neither Landlord nor Tenant shall have any obligation to the other under
this Article Twenty-Seven.

     (p)  If Tenant does not exercise any of the Expansion Options set forth in
this Article Twenty-Seven, Tenant will still have a Right of First Offer, as set
forth in Article Twenty-Eight below, as well as a Contraction Option, as set
forth in Article Thirty, and a Termination Option, as set forth in Article
Thirty-One.

     (q)  The anticipated possession date shall be the date identified in
Landlord's Notice, which is the date the respective Expansion Space will be
delivered to Tenant for the construction of its tenant improvements. In the
event that Landlord does not deliver the expansion space to Tenant as set forth
in Landlord's Notice and Tenant is unable to have a minimum of ninety days of
pre-commencement access, then Landlord will grant Tenant a 1-for-1 day delay in
Tenant's lease commencement for the respective expansion space.

     (r)  In the event Landlord does not or is unable to deliver possession of
the expansion space to Tenant as set forth above, due solely to "Landlord's
Delay"(as defined below), then Tenant shall be entitled to abate the portion of
the Monthly Rent and Additional Rent attributable to such space on a 2 days for
every 1 day delay basis until such time as possession of the particular space is

                                       51
<PAGE>

delivered (i.e. if such space is delivered 10 days late, then commencing on
Tenant's Commencement Date for said expansion space, Tenant shall be entitled to
the sum of 20 days' abatement of Monthly Rent and Additional Rent for said
space); provided, however, that if Landlord does not or is unable to deliver
possession of said premises by a date which is 90 days or more beyond the
anticipated Possession Date, then, in lieu of rent abatement as aforesaid,
Tenant shall have the benefit of all of the remedies for Landlord's default
provided in the Lease and at Law.

     As used herein the term "Landlord's Delay" shall exclude any delays due to
Force Majeure and tenant holdover without Landlord's consent or sufferance.
Except for the above exclusions, Landlord's Delay shall mean any delay on the
part of the Landlord in delivering to Tenant possession of the expansion space
beyond the applicable date set forth above.

     (s)  No Landlord's Delay shall be deemed to have occurred unless and until
Tenant has given written notice to Landlord of the Landlord's Delay in question.
If such action or inaction is in fact a Landlord's Delay, and is not cured
within 3 business days after Landlord's receipt of such notice, then a
Landlord's Delay shall be deemed to have occurred commencing upon the first day
after the scheduled Possession Date for the expansion space in question.

     (t)  In connection with each of the expansion options set forth in this
Article Twenty-Seven, Landlord will use commercially reasonable efforts to make
all of the spaces delivered to Tenant contiguous to itself in each option
period.

                             ARTICLE TWENTY-EIGHT
                             RIGHT OF FIRST OFFER

     (a)  During the Term, Tenant shall have a continuing right of first offer
(the "Offer Right") with respect to all or any portion of the space located in
the Low Rise or "Mid Rise" (floors 14 - 23) of the Building being marketed to
third party tenants, subject to the existing rights of other tenants' as set
forth in leases granted as of the date this Lease is fully executed (the "Offer
Space").  Whenever any Offer Space becomes or is to become available, Landlord
shall notify Tenant in writing of such fact "Landlord's First Offer Notice".
Landlord's First Offer Notice shall include a floor plan of the Offer Space,
state the date of availability of the Offer Space, include a statement as to
whether the Offer Space is also considered to be Expansion Space or Subordinate
Expansion Space and set forth such other terms (including Landlord's
determination of Monthly Base Rent) under which Landlord is willing to lease the
Offer Space. Landlord's First Offer Notice shall not be given earlier than nine
(9) months prior to the date designated by Landlord as the date such Offer Space
will become available nor later than thirty (30) days after the date on which
the Offer Space became available for leasing.  The Monthly Base Rent for the
Offer Space shall be calculated at Market Rate (as defined in Section 25(s)
hereof) multiplied by the rentable area of the Offer Space.  The Offer Space
shall be delivered to Tenant on the availability date set forth in Landlord's
First Offer Notice for the remainder of the Term in an AS IS condition, except
with respect to the conditions set forth in Exhibit F - Base Building
                                            ---------
Conditions, and Landlord has no obligation to make any improvement to the Offer
Space.

                                       52
<PAGE>

     (b)  Tenant shall respond to Landlord's First Offer Notice within ten (10)
business days after receipt of its determination to accept, reject or submit for
arbitration Landlord's determination of the Market Rent set forth therein (as
outlined in Article Twenty-Six above). If Tenant elects to submit to
arbitration, Tenant shall name its arbitrator in its notice to Landlord that it
has selected arbitration. Tenant shall also have the right to elect to reject
the Offer Space if Landlord has determined that such space is a part of the
space available to Tenant pursuant to the Expansion Options set forth in Article
Twenty-Seven hereto or space available to Tenant pursuant to the Subordinate
Expansion Options set forth in Article Twenty-Nine hereto and such space shall
remain available to Tenant pursuant to the provisions of said Article Twenty-
Seven or Article Twenty-Nine, as applicable.  Tenant's failure to respond within
such time period shall be a waiver of Tenant's Offer Right with respect to such
Offer Space.

     (c)  It shall be a condition to Tenant's exercise of the Offer Right that
both at the time of the exercise of the Offer Right and at the time the Offer
Space is delivered: (i) Tenant is not in Default under this Lease, and (ii)
except as may be permitted below, Tenant and/or an Affiliate is occupying the
Premises for the conduct of business.  Any termination of this Lease or
termination of Tenant's right of possession shall terminate Tenant's Offer
Right.  Except as set forth below, the Offer Right may be exercised only by and
is personal to Tenant and/or an Affiliate and may not be exercised by or for the
benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise the Offer Right shall not be affected by any sublease of the
Premises entered into pursuant to the terms of this Lease, but in no event shall
any sublessee have any rights to exercise said Offer Right.  In addition, the
right to exercise the Offer Right shall be automatically transferred to (i) an
Assignee who leases the entire Premises pursuant to the terms of this Lease or
(ii) to any Assignee pursuant to an Assignment of this Lease for more than 25%
of Tenant's then leased space in the Building, but shall not be transferred to
any Assignee pursuant to an Assignment of this Lease for less than 25% of
Tenant's then leased space in the Building.

     (d)  In the event that Tenant exercises the Offer Right, Tenant agrees to
enter into an amendment to this Lease reasonably acceptable to Tenant
incorporating the applicable Offer Space to the Premises and making such other
conforming changes as are necessary to the computation of the Monthly Base Rent
and the calculation of Tenant's Share applicable to such option the earlier of
(i) sixty (60) days following the exercise of the Offer Right or (ii) sixty (60)
days following the delivery of the arbitrator's decision to the parties pursuant
to the terms of Article Twenty-Six of this Lease.

     (e)  In the event Tenant fails to exercise its Offer Right as to the Offer
Space, the same shall be offered Tenant if it becomes available again within the
Term of this Lease.

     (f)  In the event that any Landlord's First Offer Notice states that the
Offer Space is also considered to be either Expansion Space or Subordinate
Expansion Space, Tenant's exercise of said Offer Right shall reduce the amount
of Expansion Space or Subordinate Expansion Space available to Tenant pursuant
to this Lease.

                                       53
<PAGE>

                              ARTICLE TWENTY-NINE
                         SUBORDINATE EXPANSION OPTION

In addition to the expansion options set forth in Article Twenty-Seven hereof,
Tenant shall have the right to lease additional space in the Mid Rise (subject
to the existing tenants' rights), as set forth below:

     (a)  If the space becomes available in 2007, Tenant shall have the right to
lease additional space with a lease commencement date in 2007 (the "2007
Subordinate Expansion Option") consisting of one or two full floors and
approximately 21,000 or 42,000 rentable square feet of space (as currently
determined, but which square footage amounts may be modified by the provisions
of Section 2.04 of this Lease) located in the Building (the "2007 Subordinate
Expansion Space") on the terms and conditions set forth herein. When the 2007
Subordinate Expansion Space becomes or is to become available, Landlord shall
notify Tenant in writing of such fact ("Landlord's 2007 Subordinate Expansion
Option Notice") with respect to the space available, including detailed existing
condition plans, if available.  The Monthly Base Rent for the 2007 Subordinate
Expansion Space shall be calculated at Market Rate (as defined in Section 25(s)
hereof) multiplied by the rentable area of the 2007 Subordinate Expansion Space
and shall commence ninety-(90) days after the 2007 Subordinate Expansion Space
is delivered to Tenant. The 2007 Subordinate Expansion Space shall be demised
for the remainder of the Term on an AS IS condition, except with respect to the
conditions set forth in Exhibit F - Base Building Conditions, and Landlord has
                        ---------
no obligation to make any improvement to the 2007 Subordinate Expansion Space,
provided however, that Landlord may contribute an amount (the "2007 Subordinate
Contribution") as determined in accordance with the provisions of Section 25(s).
The 2007 Subordinate Contribution, if any, is to be applied to Tenant's
completion of such improvements and additions to the 2007 Subordinate Expansion
Space as Tenant deems desirable including all construction improvements,
architectural and engineering fees, third party construction consultants, FF&E
expenses, or teledata related costs (the "2007 Subordinate Work").  Tenant shall
complete the 2007 Subordinate Work in accordance with the terms of this Lease,
including, without limitation, Exhibit B. If the costs of completing the 2007
                               ---------
Subordinate Work exceeds the sum of  the 2007 Subordinate Contribution, if any,
Tenant shall pay all such costs. In the event that Tenant fails to use all of
the 2007 Subordinate Contribution, if any, as set forth above within the first
twelve (12) months after the 2007 Subordinate Expansion Space is delivered to
Tenant, then the portion of the 2007 Subordinate Contribution, if any, which is
not disbursed as provided above shall be applied against installments of Rent
next due from Tenant.

     (b)  Landlord shall include in Landlord's 2007 Subordinate Expansion Option
Notice its determination of Market Rate.  Tenant shall have thirty (30) days
after receipt of Landlord's determination to accept, reject or submit for
arbitration (as outlined in Article Twenty-Six above). If Tenant elects to
submit to arbitration, Tenant shall name its arbitrator in its notice to
Landlord that it has selected arbitration.

     (c)  If the space becomes available in 2009, Tenant shall also have the
right to lease additional space with a lease commencement date in 2009 (the
"2009 Subordinate Expansion Option") consisting of one or two full floors and
approximately 21,000 or 42,000 rentable square feet of space (as currently
determined, but which square footage amounts may be modified by the

                                       54
<PAGE>

provisions of Section 2.04 of this Lease) located in the Building (the "2009
Subordinate Expansion Space") on the terms and conditions set forth herein. When
the 2009 Subordinate Expansion Space becomes or is to become available, Landlord
shall notify Tenant in writing of such fact ("Landlord's 2009 Subordinate
Expansion Option Notice") with respect to the space available, including
detailed existing condition plans, if available. The Monthly Base Rent for the
2009 Subordinate Expansion Space shall be calculated at Market Rate (as defined
in Section 25(s) hereof) multiplied by the rentable area of the 2009 Subordinate
Expansion Space and shall commence ninety-(90) days after the 2009 Subordinate
Expansion Space is delivered to Tenant. The 2009 Subordinate Expansion Space
shall be demised for the remainder of the Term on an AS IS condition, except
with respect to the conditions set forth in Exhibit F - Base Building
                                            ---------
Conditions, and Landlord has no obligation to make any improvement to the 2009
Subordinate Expansion Space, provided however, that Landlord may contribute an
amount (the "2009 Subordinate Contribution") as determined in accordance with
the provisions of Section 25(s). The 2009 Subordinate Contribution, if any, is
to be applied to Tenant's completion of such improvements and additions to the
2009 Subordinate Expansion Space as Tenant deems desirable including all
construction improvements, architectural and engineering fees, third party
construction consultants, FF&E expenses, or teledata related costs (the "2009
Subordinate Work"). Tenant shall complete the 2009 Subordinate Work in
accordance with the terms of this Lease, including, without limitation, Exhibit
                                                                        -------
B. If the costs of completing the 2009 Subordinate Work exceeds the sum of the
-
2009 Subordinate Contribution, if any, Tenant shall pay all such costs. In the
event that Tenant fails to use all of the 2009 Subordinate Contribution, if any,
as set forth above within the first twelve (12) months after the 2009
Subordinate Expansion Space is delivered to Tenant, then the portion of the 2009
Subordinate Contribution, if any, which is not disbursed as provided above shall
be applied against installments of Rent next due from Tenant.

     (d)  Landlord shall include in Landlord's 2009 Subordinate Expansion Option
Notice its determination of Market Rate.  Tenant shall have thirty (30) days
after receipt of Landlord's determination to accept, reject or submit for
arbitration (as outlined in Article Twenty-Six above). If Tenant elects to
submit to arbitration, Tenant shall name its arbitrator in its notice to
Landlord that it has selected arbitration.

     (e)  The 2007 Subordinate Expansion Option and the 2009 Subordinate
Expansion Option are herein collectively referred to as the "Subordinate
Expansion Options".

     (f)  It shall be a condition to Tenant's exercise of either the 2007
Subordinate Expansion Option or the 2009 Subordinate Expansion Option that both
at the time of delivery of Landlord's 2007 Subordinate Expansion Option Notice
or the 2009 Subordinate Expansion Option Notice and at the commencement of the
Term with respect to either the 2007 Subordinate Expansion Option or the 2009
Subordinate Expansion Option: (i) Tenant is not in Default under this Lease, and
(ii) except as may be permitted below, Tenant and/or an Affiliate is occupying
the Premises for the conduct of business.  Any termination of this Lease or
termination of Tenant's right of possession shall terminate all of Tenant's
rights to any of the remaining Subordinate Expansion Options.  Except as set
forth below, either of the Subordinate Expansion Options may be exercised only
by and is personal to Tenant and/or an Affiliate and may not be exercised by or
for the benefit of any other party.

                                       55
<PAGE>

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise either of the Subordinate Expansion Options shall not be
affected by any sublease of the Premises entered into pursuant to the terms of
this Lease, but in no event shall any sublessee have any rights to exercise
either of said Subordinate Expansion Options.  In addition, the right to
exercise either of the Subordinate Expansion Options shall be automatically
transferred to (i) an Assignee who leases the entire Premises pursuant to the
terms of this Lease or (ii) to any Assignee pursuant to an Assignment of this
Lease for more than 25% of Tenant's then leased space in the Building, but shall
not be transferred to any Assignee pursuant to an Assignment of this Lease for
less than 25% of Tenant's then leased space in the Building.

     (g)  In the event that Tenant exercises either of the foregoing Subordinate
Expansion Options, Tenant agrees to enter into an amendment to this Lease
reasonably acceptable to Tenant incorporating the applicable Subordinate
Expansion Space to the Premises and making such other conforming changes as are
necessary to the computation of the Monthly Base Rent and the calculation of
Tenant's Share applicable to such option the earlier of (i) sixty (60) days
following the exercise of the either of the Subordinate Expansion Options or
(ii) thirty (30) days following the delivery of the arbitrator's decision to the
parties pursuant to the terms of Article Twenty-Six of this Lease.  The
Subordinate Expansion Option Spaces shall be leased for their respective Terms
upon the terms and conditions provided for in this Lease, except for such
changes as are required pursuant to the terms hereof, which shall be as set
forth in the Amendment described above.  If Tenant does not execute and deliver
the Amendment to this Lease to Landlord as set forth above, neither Landlord nor
Tenant shall have any obligation to the other under this Article Twenty-Nine.

     (h)  If the 2007 Subordinate Expansion Space becomes available before 2007
or the 2009 Subordinate Expansion Space becomes available before 2009, then
Tenant shall have the Offer Right set forth in Article Twenty-Eight hereof. In
the event Tenant fails to exercise its Offer Right as to either of the
Subordinate Expansion Spaces, the same shall be offered Tenant if it becomes
available again before the respective Subordinate Expansion Option is available.
Furthermore regardless of the number of times tenant fails to exercise its Offer
Right with respect to either of the Subordinate Expansion Spaces, the provisions
of this Article Twenty-Nine shall remain in full force and effect.

     (i)  As long as Tenant is leasing at least 129,097 rentable square feet
under this Lease, then no previously exercised Contraction Option (as set forth
below) shall affect Tenant's Subordinate Expansion Options as defined herein.
If, at any point in time, Tenant has exercised a Contraction Option and leases
less than 129,097 rentable square feet, the next Subordinate Expansion Option
only will become null and void.

                                ARTICLE THIRTY
                              CONTRACTION OPTION

     (a)  Tenant shall have the option (the "First Contraction Option") to
contract its premises by  8,000 to 10,000 rentable square feet (the "First
Contraction Space") effective any time during the year 2006.  If Tenant elects
to exercise the First Contraction Option, Tenant shall notify Landlord of its
intent to do so (the "Tenant's First Contraction Notice") no less than twelve
(12) months prior to the effective date thereof.  Tenant shall pay Landlord a
sum equal to two (2) years

                                       56
<PAGE>

of the then-escalated gross rent which would next become due in connection with
the First Contraction Space after the effective date set forth in Tenant's First
Contraction Notice (the "First Contraction Payment"). Tenant shall pay the First
Contraction Payment one-half (1/2) upon delivery of Tenant's First Contraction
Notice and one-half (1/2) thirty (30) days prior to the effective date.

     (b)  Tenant shall also have the option (the "Second Contraction Option") to
contract its premises by  10,000 to 20,000 rentable square feet (the "Second
Contraction Space") effective any time during the year 2008.  If Tenant elects
to exercise the Second Contraction Option, Tenant shall notify Landlord of its
intent to do so (the "Tenant's Second Contraction Notice") no less than twelve
(12) months prior to the effective date thereof.  Tenant shall pay Landlord a
sum equal to two (2) years of the then-escalated gross rent which would next
become due in connection with the Second Contraction Space after the effective
date set forth in Tenant's Second Contraction Notice (the "Second Contraction
Payment").  Tenant shall pay the Second Contraction Payment one-half (1/2) upon
delivery of Tenant's Second Contraction Notice and one-half (1/2) thirty (30)
days prior to the effective date.

     (c)  Tenant shall also have the option (the "Third Contraction Option") to
contract its premises by  10,000 to 20,000 rentable square feet (the "Third
Contraction Space") effective any time during the year 2012.  If Tenant elects
to exercise the Third Contraction Option, Tenant shall notify Landlord of its
intent to do so (the "Tenant's Third Contraction Notice") no less than twelve
(12) months prior to the effective date thereof.  Tenant shall pay Landlord a
sum equal to two (2) years of the then-escalated gross rent which would next
become due in connection with the Third Contraction Space after the effective
date set forth in Tenant's Third Contraction Notice (the "Third Contraction
Payment").  Tenant shall pay the Third Contraction Payment one-half (1/2) upon
delivery of Tenant's Third Contraction Notice and one-half (1/2) thirty (30)
days prior to the effective date.

     (d)  The First Contraction Option, the Second Contraction Option and the
Third Contraction Option are herein collectively referred to as the "Contraction
Options".

     (e)  It shall be a condition to Tenant's exercise of any of the Contraction
Options that, both at the time of the exercise of the Contraction Option and at
the effective date thereof, Tenant is not in Default under this Lease.

     (f)  Tenant shall use commercially reasonable efforts to deliver to
Landlord space consisting of no less than 5,000 square feet of Rentable Area of
a commercially leaseable configuration with a proportional window to floor
ratio. If Tenant shall exercise any of the Contraction Options set forth in this
Article Twenty-Nine, the next effective Expansion or Subordinate Expansion
Option provided for in this Lease shall be waived by Tenant.

     (g)  Tenant's failure to strictly comply with the provisions regarding the
Contraction Options shall nullify any attempted exercise of the Contraction
Options by Tenant.  Except as set forth below, the Contraction Options may be
exercised only by and is personal to Tenant or an Affiliate and may not be
exercised by or for the benefit of any other party.

                                       57
<PAGE>

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise any of the Contraction Options shall not be affected by any
sublease of the Premises entered into pursuant to the terms of this Lease, but
in no event shall any sublessee have any rights to exercise any of said
Contraction Options.  In addition, the right to exercise any of the Contraction
Options shall be automatically transferred to (i) an Assignee who leases the
entire Premises pursuant to the terms of this Lease or (ii) to any Assignee
pursuant to an Assignment of this Lease for more than 25% of Tenant's then
leased space in the Building, but shall not be transferred to any Assignee
pursuant to an Assignment of this Lease for less than 25% of Tenant's then
leased space in the Building.

                              ARTICLE THIRTY-ONE
                              TERMINATION OPTION

Tenant shall have the option (the "Termination Option") to terminate this Lease
effective as of the last day of December 31, 2010 (the "Termination Effective
Date").   If Tenant elects to exercise the Termination Option, Tenant shall
notify Landlord of its intent to do so (the "Tenant's Termination Notice") no
later than June 30, 2008.  Tenant shall pay Landlord a sum equal to two (2)
years of the then-escalated gross rent which would next become due after the
Effective Date (the "Termination Payment").  Tenant shall pay the Termination
Payment one-half (1/2) upon delivery of Tenant's Termination Notice and one-half
(1/2) December 1, 2010.  It shall be a condition to Tenant's exercise of the
Termination Option that, both at the time of the exercise of the Termination
Option and on the Termination Effective Date, Tenant is not in Default under
this Lease.  Tenant's failure to strictly comply with the provisions regarding
the Termination Option shall nullify any attempted exercise of the Termination
Option by Tenant. Except as set forth below, the Termination Option may be
exercised only by and is personal to Tenant or an Affiliate and may not be
exercised by or for the benefit of any other party.

     Notwithstanding anything to the contrary contained in this Lease, Tenant's
rights to exercise the Termination Option shall not be affected by any sublease
of the Premises entered into pursuant to the terms of this Lease, but in no
event shall any sublessee have any rights to exercise said Termination Option.
In addition, the right to exercise the Termination Option shall be automatically
transferred to an Assignee who leases the entire Premises pursuant to the terms
of this Lease, but shall not be available to any Assignee pursuant to an
Assignment of this Lease for less than all of Tenant's then leased space in the
Building.

                              ARTICLE THIRTY-TWO
                                    SIGNAGE

     (a)  Tenant shall have the right, upon leasing, occupying and maintaining
under lease at least 191,000 rentable square feet in the Building, to control
naming rights to the Building once the rights currently granted to Chase Bank
have either expired or been relinquished pursuant to the terms of the Chase Bank
lease now in effect. Not withstanding the foregoing, Landlord agrees not to
grant Building naming rights to any other tenant who leases or will lease less
than 150,000 rentable square feet.

                                       58
<PAGE>

     (b)  If Tenant is granted naming rights to the Building as set forth above,
Tenant will be permitted to furnish and install signage on the exterior of the
Building at Tenant's sole expense. The exact size, location and design of the
signage shall be similar to the Chase Bank signage and shall be approved by
Landlord which consent shall not be unreasonably withheld or delayed.

     (c)  As long as Tenant leases at least 129,097 rentable square feet in the
Building, Tenant shall have the right to install an identification sign on the
elevator wall at a low-rise elevator bank using Tenant's standard corporate logo
or graphics. All signs shall be affixed in such manner as reasonably approved by
Landlord.  The size and location of the signage shall be mutually agreed upon by
Landlord and Tenant. Except as hereinprovided, Tenant shall not display,
maintain or affix on any place on or about the Building any sign, notice, legend
or advertisement.

                             ARTICLE THIRTY-THREE
                               PERSONNEL BRIDGE

     (a)  Pursuant to the terms and conditions of the Prior Lease, Tenant has
constructed and currently is responsible for the Bridge.  Tenant shall, at its
sole cost and expense, be responsible for the operation (including, without
limitation, security, heating, cooling and cleaning of the interior and exterior
of the Bridge), repair, maintenance and replacement of the Bridge.  Without
limiting the foregoing, Tenant shall, at its sole cost and expense, at all times
maintain the Bridge in good order, appearance, condition and repair and shall
comply with all applicable Laws.  Tenant shall, at its sole cost and expense,
repair and restore or demolish the Bridge if damaged by any fire or other
casualty.  Tenant shall pay all real estate taxes in connection with or
attributable to the Bridge, including, without limitation, any increases in the
real estate taxes for the Building attributable to the Bridge.   Upon expiration
of the Term hereof or upon any termination of this Lease, the provision of
Section 12.01 hereof shall apply.

     (b)  Tenant agrees to indemnify and hold harmless the Indemnitees from and
against any and all claims, demands, actions, liabilities, damages, costs and
expenses (including court costs and reasonable attorneys' fees), for injuries to
all persons and damage to or loss of property arising in connection with the
Bridge, including, without limitation, any and all claims, demands, actions,
liabilities, damages, costs and expenses arising from any breach of security of
the Premises or the Building in connection with the Bridge, from the maintenance
and condition of the Bridge, from any activity, use, work, or thing done,
permitted or suffered by Tenant in or about the Bridge or from any breach or
default on the part of Tenant in the performance of any covenant or agreement on
the part of Tenant to be performed under this Lease in connection with the
Bridge or due to any other act or omission of Tenant, its agents or employees in
connection with the Bridge.  If any such proceeding is filed against any of the
Indemnitees, Tenant agrees, upon Landlord's request, to defend such proceeding
at its sole cost by legal counsel reasonably satisfactory to Landlord.

     (c)  Tenant shall have no right to assign, transfer or otherwise dispose of
its rights or interests under this Article Thirty-Three, such rights being
granted solely to The Northern Trust Company; provided however, that any
Affiliate shall be entitled to the rights granted to Tenant hereunder.

                                       59
<PAGE>

                              ARTICLE THIRTY-FOUR
                                 MISCELLANEOUS

34.01  LATE CHARGES

All payments required hereunder (other than the Monthly Base Rent, Rent
Adjustments, and Rent Adjustment Deposits, which shall be due as hereinbefore
provided) to Landlord shall be paid within thirty (30) days after Landlord's
demand therefor.  All such amounts (including, without limitation Monthly Base
Rent, Rent Adjustments, and Rent Adjustment Deposits) not paid when due shall
bear interest from the date due until the date paid at the Default Rate in
effect on the date such payment was due.

34.02  WAIVER OF JURY TRIAL

As a material inducement to the parties to enter into this Lease, Landlord and
Tenant each hereby waive their respective right to a trial by jury of any issues
relating to or arising out of its obligations under this Lease or its occupancy
of the Premises.  The parties acknowledge that they have read and understood the
foregoing provision.

34.03  OPTION

This Lease shall not become effective as a lease or otherwise until executed and
delivered by both Landlord and Tenant. The submission of the Lease to Tenant
does not constitute a reservation of or option for the Premises, except that it
shall constitute an irrevocable offer on the part of Tenant in effect for five
(5) business days to lease the Premises on the terms and conditions herein
contained.

34.04  TENANT AUTHORITY

Tenant represents and warrants to Landlord that it has full authority and power
to enter into and perform its obligations under this Lease, that the person
executing this Lease is fully empowered to do so, and that no consent or
authorization is necessary from any third party.  Landlord may request that
Tenant provide Landlord evidence of Tenant's authority.

34.05  ENTIRE AGREEMENT

This Lease, the Exhibits attached hereto and the Workletter contain the entire
agreement between Landlord and Tenant concerning the Premises and there are no
other agreements, either oral or written, and no other representations or
statements, either oral or written, on which Tenant has relied. This Lease shall
not be modified except by a writing executed by Landlord and Tenant.

34.06  MODIFICATION OF LEASE FOR BENEFIT OF MORTGAGEE

If Mortgagee of Landlord requires a modification of this Lease which shall not
result in any increased cost or expense to Tenant or in any other substantial
and adverse change in the rights and obligations of Tenant hereunder, then
Tenant agrees that the Lease may be so modified.

                                       60
<PAGE>

34.07  SATELLITE SYSTEM

During the term of this Lease (and any amendments or renewals), Tenant shall
have an option to enter into a non-exclusive license (the "License") to install,
operate, maintain and operate a reception-only satellite dish antenna, mounted
on a non-penetrating structure, and related plenum-rated cabling (the "System"),
upon and subject to the terms and conditions set forth in Exhibit I attached
hereto and made a part hereof.

34.08  EXCULPATION

Tenant agrees, on its behalf and on behalf of its successors and assigns, that
any liability of Landlord with respect to this Lease shall never exceed the
amount of offset which Tenant utilizes pursuant to Section 11.05 of this Lease
plus an amount not to exceed $10,000,000 (the "Liability Cap") and Tenant shall
not be entitled to recover from Landlord any amounts in excess of the Liability
Cap.

34.09  ACCORD AND SATISFACTION

No payment by Tenant or receipt by Landlord of a lesser amount than any
installment or payment of Rent due shall be deemed to be other than on account
of the amount due, and no endorsement or statement on any check or any letter
accompanying any check or payment of Rent shall be deemed an accord and
satisfaction, and Landlord may accept such check or payment without prejudice to
Landlord's right to recover the balance of such installment or payment of Rent
or pursue any other remedies available to Landlord.  No receipt of money by
Landlord from Tenant after the termination of this Lease or Tenant's right of
possession of the Premises shall reinstate, continue or extend the Term.

34.10  LANDLORD'S OBLIGATIONS ON SALE OF BUILDING

In the event of any sale or other transfer of the Building, Landlord shall be
entirely freed and relieved of all agreements and obligations of Landlord
hereunder accruing or to be performed after the date of such sale or transfer,
provided that all of Landlord's obligations hereunder are specifically assumed
by the buyer or transferee.

34.11  BINDING EFFECT

This Lease shall be binding upon and inure to the benefit of Landlord and Tenant
and their respective heirs, legal representatives, successors and permitted
assigns.

34.12  CAPTIONS

The Article and Section captions in this Lease are inserted only as a matter of
convenience and in no way define, limit, construe, or describe the scope or
intent of such Articles and Sections.

                                       61
<PAGE>

34.13  APPLICABLE LAW

This Lease shall be construed in accordance with the laws of the State of
Illinois.  If any term, covenant or condition of this Lease or the application
thereof to any person or circumstance shall, to any extent, be invalid or
unenforceable, the remainder of this Lease, or the application of such term,
covenant or condition to persons or circumstances other than those as to which
it is held invalid or unenforceable, shall not be affected thereby and each
item, covenant or condition of this Lease shall be valid and be enforced to the
fullest extent permitted by law.

34.14  ABANDONMENT

In the event Tenant vacates or abandons the Premises but is otherwise in
compliance with all the terms, covenants and conditions of this Lease, Landlord
shall (i) have the right to enter into the Premises in order to show the space
to prospective tenants during the last twelve (12) months of the Term and in
accordance with the provisions of Section 7.02 of this Lease, and (ii) have the
right to reduce the services provided to Tenant pursuant to the terms of this
Lease to such levels as Landlord reasonably determines to be adequate services
for an unoccupied premises. Tenant expressly acknowledges that in the absence of
written notice pursuant to Section 11.02(a), hereof, none of the foregoing acts
of Landlord or any other act of Landlord shall constitute a termination of
Tenant's right to possession or an acceptance of Tenant's surrender of the
Premises, and the Lease shall continue in effect. As long as Tenant is not in
monetary default, or any other default, neither vacating the Premises nor
discontinued occupancy shall constitute a default by Tenant.

34.15  LANDLORD'S RIGHT TO PERFORM TENANT'S DUTIES

If Tenant fails timely to perform any of its duties under this Lease or the
Workletter within the time frames provided for in this Lease or within thirty
(30) days of receipt of notice from Landlord of its failure to so perform
(except with respect to the payment of Rent which shall be in accordance with
the provisions of Section 11.01(a)(i)), Landlord shall have the right (but not
the obligation), to perform such duty on behalf and at the expense of Tenant
without additional prior notice to Tenant, and all reasonable sums expended or
expenses incurred by Landlord in performing such duty shall be deemed to be
additional Rent under this Lease and shall be due and payable thirty (30) days
after request for payment.

34.16  GENERATOR

Tenant shall have to right to elect to install a generator in the Building to
serve the Premises to the extent that Landlord has space available which has
been designated for such use.  Tenant shall notify Landlord of such election in
writing indicating the type and size of the generator.  Landlord shall, within
thirty (30) days of such notice of election, inform Tenant as to whether there
is any space available and, if so, of the terms on which Landlord would enter
into a license agreement for such space and the location at which such generator
could be placed (the "Generator Terms").  Tenant shall thereafter have twenty
(20) days to notify Landlord if it accepts or declines the Generator Terms and,
if Tenant accepts the Generator Terms, it must provide Landlord with the actual
plans and specs for such generator.  Landlord shall thereafter have an
additional twenty(20) days to approve such plans and if Landlord approves the
plans and specs, Landlord and Tenant

                                       62
<PAGE>

shall enter into a license agreement for such generator in form and substance
reasonably satisfactory to both parties within the succeeding sixty (60) day
period. Said license agreement will govern the installation, operation and
maintenance of the generator and shall also provide that Tenant, at Tenant's
sole expense, will comply with all Laws governing the installation, operation
and maintenance of the generator.

34.17  RIDERS

All Riders attached hereto and executed both by Landlord and Tenant shall be
deemed to be a part hereof and hereby incorporated herein.

     IN WITNESS WHEREOF, this Lease has been executed as of the date set forth
in Section 1.01(4) hereof.

LANDLORD:                                TENANT:

METROPOLITAN LIFE INSURANCE              THE NORTHERN TRUST COMPANY
COMPANY

By:    /s/ Donald K. Devine              By:     /s/ James R. Taylor
    -----------------------                  -----------------------
    Its:   Vice President                    Its:    Vice President
           ----------------                     --------------------

                                       63
<PAGE>

                                 SCHEDULE ONE

                        Controllable Operating Expenses
                        -------------------------------

<TABLE>
<CAPTION>
          Cap Amount          Scenario 1                 Scenario 2
                        Actual/Paid(Difference)    Actual/Paid(difference)
                        -----------------------    -----------------------
<S>       <C>           <C>                        <C>
Year 1    6.00%         10.0%/6.0%(-4.0%)          6.0%/6.0%(0%)

Year 2    6.36%         10.0%/6.36%(-7.64%)        6.0%/6.0%(+.36%)

Year 3    6.74%         5.0%/6.74%(-5.9%)          6.0%/6.0%(+1.10%)

Year 4    7.15%         5.0%/7.15%(-3.75%)         6.0%/6.0%(+2.25%)

Year 5    7.57%         5.0%/7.57%(-1.18%)         12.0%/7.57%(-4.43%)

Year 6    None          12.0%/12/0%*               8.0%/10.25%**
</TABLE>

*No "catch-up" since every prior year reached the maximum allowable - shortfall
of 1.18% will not be paid

**"Catch-up" applies to the extent that 2.25% was not used in prior years -
shortfall of  2.18% will not be paid

                           Schedule A - Page 1 of 1

<PAGE>

                                   EXHIBIT A

                               PLAN OF PREMISES
                               ----------------

                              EXHIBIT A - Page 1
<PAGE>

                                   EXHIBIT B

                             WORKLETTER AGREEMENT

This agreement (the "Agreement") is attached to and made a part of the Office
Lease dated ________________ (the "Lease") between Metropolitan Life Insurance
Company, a New York corporation and The Northern Trust Company, an Illinois
corporation.  The terms of this Agreement shall be applicable to the Tenant Work
and shall not be applicable to Tenant Alterations as set forth in Article Nine
of the Lease.  Any terms used in this Agreement which are not otherwise defined
shall have the same meaning as in the Lease.

     1.   On the Commencement Date, Tenant shall have accepted the Initial
Premises in an AS IS condition and Tenant shall perform the Tenant Work as set
forth herein and in the Lease.

     In the event that Tenant exercises any of the options set forth in Articles
Twenty-Seven, Twenty-Eight or Twenty-Nine with respect to adding additional
space to the Premises, the following provision shall also apply:

     On the Commencement Date of each option set forth above, Tenant shall have
accepted the applicable Premises in an AS IS condition and Tenant shall perform
such Tenant Work in the Premises as are necessary for Tenant to operate its
business from the Premises in accordance with the terms and conditions set forth
herein.

     2.   Tenant shall cause to be prepared such architectural, design,
mechanical, electrical, plumbing and other plans (the "Tenant Plans") as are
necessary for completion of the Tenant Work.  Tenant shall submit the Tenant
Plans to Landlord for its approval, which approval shall not be unreasonably
withheld.  Landlord shall complete its review of the Tenant Plans within five
(5) business days following receipt thereof and Landlord shall take all
reasonable steps to avoid causing any delay to Tenant's completion of the Tenant
Work.  In the event of any exception by Landlord to Tenant Plans, Tenant shall
take steps to appropriately modify the Tenant Plans and shall resubmit the
revised Tenant Plans to Landlord, which shall again be reviewed within five (5)
business days following receipt.

     Landlord's approval of the Tenant Plans shall in no way be deemed
assurances that the Tenant Work complies with applicable laws, ordinances or
codes, or any implied warranty of the adequacy or sufficiency of the design or
quality of any items shown therein.  Landlord shall cooperate with Tenant by
signing any documents required to enable Tenant to obtain a building permit and
whatever authorizations are required to proceed with the Tenant Work when
requested by Tenant, even if such request is made prior to Landlord's approval
of Tenant Plans.  Landlord shall not be deemed to have waived its right to
approve or disapprove Tenant Plans if Landlord has not approved Tenant Plans at
the time it signs such documents.

     3.   Tenant shall make such contracts and arrangements as Tenant determines
to be necessary and desirable for the construction and installation of Tenant
Work using contractors and subcontractors reasonably acceptable to Landlord.
Landlord agrees that Landlord shall approve or

                              EXHIBIT B - Page 1
<PAGE>

disapprove any general contractor and/or subcontractors within five (5) business
days after submission by Tenant.

     4.   Prior to the commencement of the construction and installation of the
Tenant Work, or the delivery of any materials to the Premises or the Building,
Tenant shall (a) procure all required licenses, permits and approvals from all
governmental authorities including, but not limited to, the substitution of
Tenant's self-certification in connection therewith as may be acceptable to the
City of Chicago Building Department from time to time, and (b) deliver to
Landlord certificates evidencing the following insurance coverages which are
required by Landlord of general contractor and which shall remain in effect for
so long as any Tenant Work is being undertaken or performed on the Premises or
in the Building: Comprehensive General Liability policies having a single
aggregate limit of $5,000,000, covering operations and premises liability,
completed operations liability, broad form property damage, personal injury,
blanket contractual liability insurance coverage, independent contractor's
coverage, and workers' compensation in statutory amounts.  Tenant shall also
deliver to Landlord copies of certificates evidencing such insurance as shall be
required by the general contractor of any sub-contractors who work in the
Building.  The completed operations liability coverage shall continue in force
for one year after the date of the substantial completion of the Tenant Work.
Tenant agrees to defend and hold the Indemnitees harmless from all actions,
claims, liability and damages in any way arising out of or relating to the
construction and installation of the Tenant Work in the Premises other than for
claims, actions, liability and damages arising out of the negligence or
misconduct of Landlord, its employees, agents, contractors or subcontractors,
and to name the Indemnitees as additional insured parties as their interests may
appear in such insurance policies.

     5.   Tenant agrees to construct and install the Tenant Work using quality
materials and workmanship compatible with the Building.  Tenant shall use
qualified craftsmen and laborers who are compatible with the trade unions
operating in the Building and Tenant shall use its reasonable efforts to avoid
labor unrest in the Premises and in the Building.  Tenant shall, with Landlord's
prior approval, schedule the delivery of materials and performance of work in
the Premises and Building in such manner as not to disrupt Building operations,
which approval shall not be unreasonably withheld.  The loading dock and freight
elevators are open Monday through Friday, 7:30 a.m. to 4:00 p.m.  Exclusive use
of the facilities is scheduled on a first-come, first-served basis, with the
Office of the Building, subject to Landlord's reasonable scheduling guidelines.
Landlord shall cooperate with Tenant and Tenant's contractor in permitting
access to the Premises through freight elevator and loading docks, subject to
Landlord's reasonable scheduling guidelines. Landlord will allow Tenant to use
the Building freight elevators and loading dock after normal business hours at
no additional charge except for the actual cost of such additional security
and/or elevator operator personnel that Landlord may deem necessary.

     6.   During completion of the Premises, Tenant shall not be charged for
utility usage within the Premises.  Tenant shall pay costs for hoisting and
freight elevator usage in accordance with Landlord's regular published rates
therefor. If Tenant does not request Landlord to provide project management
services, Tenant shall reimburse Landlord's reasonable actual out-of-pocket
expenses for any necessary consultants to review plans and specifications.

                              EXHIBIT B - Page 2
<PAGE>

     7.   Landlord shall disburse each of the Contribution, the 2001
Contribution, the 2004 Contribution, the 2005 Contribution, the 2007
Contribution, the 2011 Contribution, the 2007 Subordinate Contribution and the
2009 Subordinate Contribution no more often than once monthly as and when the
Tenant Work progresses within thirty (30) days following submission of lien
waivers and such other documentation as Landlord shall reasonably require, all
as further set forth on Schedule A attached hereto and made a part hereof,
subject to Tenant's right to apply any or all of such Contributions against Rent
in accordance with the provisions of the Lease.

     8.   Upon completion of the Tenant Work and the Tenant's acceptance
thereof, Tenant shall so certify to Landlord and Tenant shall deliver to
Landlord copies of the final affidavits, certificates and copies of waivers of
lien of Tenant and all contractors, subcontractors and materialmen and the
copies of affidavit of Tenant's architect certifying that all the Tenant Work
has been constructed and installed in the Premises in substantial conformity
with the Tenant Plans, as from time to time amended with Landlord's approval.

     9.   Tenant accepts, assumes and shall be solely responsible for all risks
for the construction and installation of the Tenant Work other than for risks
resulting from the negligence or misconduct of Landlord, its employees, agents,
contractors or subcontractors.  Except as set forth in the Lease, the
Indemnitees shall have no liability or obligation to Tenant or to any other
parties, and make no warranties or representations, including any warranty of
fitness for particular use, to Tenant by reason of any approval, consultation or
other services provided by Landlord or Manager, its or their employees, agents,
contractors or subcontractors.  Landlord shall have no responsibility to Tenant
or to any other parties for the construction and installation of the Tenant
Work.

     10.  Tenant shall have access to the Premises for the purposes of
installation of the Tenant Work and such access and construction shall be in
accordance with the provisions of this Rider and other provisions of the Lease.
Tenant agrees that any such entry into and access to the Premises shall be
deemed to be under all of the terms, covenants, conditions and provisions of the
Lease, except as to the covenant to pay Rent.  Tenant further agrees that to the
extent permitted by law, and excepting the negligence or misconduct of Landlord
(and its employees or agents) and the Indemnitees, Landlord and the Indemnitees
shall not be liable in any way for any injury or death to any person or persons,
loss or damage to any Tenant Work and installations made in the Premises or loss
or damage to property placed therein the same being at Tenant's sole risk.

     11.  Within sixty days following Tenant's occupancy of the Premises for the
conduct of business, Tenant shall provide Landlord with a set of "as built"
plans, drawings and specifications for the Premises and a list of all building
materials used in the completion of the Tenant Work (by manufacturer and lot
numbers), including for example, ceiling tile, wall coverings, floor coverings
and adhesives.

                              EXHIBIT B - Page 3
<PAGE>

                                  Schedule A
                                  ----------

                              TENANT CONTRIBUTION
                           REIMBURSEMENT GUIDELINES

The following conditions are necessary to process tenant improvement
reimbursements.  All reimbursements are processed as provided in the Lease.

1)   For partial or full payments of tenant improvement reimbursements, provide
     a letter to CB Richard Ellis, Inc., Attention: Office of the Building,
     formally requesting the reimbursement along with the following documents:

     a)   Cover sheet listing each contractor and the corresponding payment
          request amount

     b)   A copy of the payment request followed by the corresponding original
          lien waiver for:

          i)   The general contractor covering the full value of the request

          ii)  Each sub-contractor, including architectural and engineering
               consultants

     c)   The lien waiver must name Metropolitan Life Insurance Company, as
          owner.

2)   Electrical and data contractors are required to repair fire stop
     penetrations and to remove debris.  Inspection of electrical and telephone
     closets will take place after final request for payment is received.  The
     following charges will apply if the accompanying condition is present:

     a)   Removal of debris, including wire, pipe, garbage, etc.    $75.00
     b)   Each fire stop penetration repair                         $50.00

                              EXHIBIT B - Page 4
<PAGE>

                                   EXHIBIT C

                             RULES AND REGULATIONS
                             ---------------------

1.   No sign, lettering, picture, notice or advertisement shall be placed on any
outside window or in a position to be visible from outside the Premises and if
visible from the outside or public corridors within the Building shall be
installed in such manner and be of such character and style as Landlord shall
approve in writing.

2.   Tenant shall not use the name of the Building for any purpose other than
Tenant's business address; Tenant shall not use the name of the Building for
Tenant's business address after Tenant vacates the Premises; nor shall Tenant
use any picture or likeness of the Building in any circulars, notices,
advertisements or correspondence.

3.   No article which is explosive or inherently dangerous is allowed in the
Building.

4.   Tenant shall not represent itself as being associated with any company or
corporation by which the Building may be known or named.

5.   Sidewalks, entrances, passages, courts, corridors, halls, elevators and
stairways in and about the Premises shall not be obstructed.

6.   No animals (except for dogs in the company of a blind person), pets,
bicycles or other vehicles shall be brought or permitted to be in the Building
or the Premises.

7.   Room-to-room canvasses to solicit business from other tenants of the
Building are not permitted; Tenant shall not advertise the business, profession
or activities of Tenant conducted in the Building in any manner which violates
any code of ethics by any recognized association or organization pertaining to
such business, profession or activities.

8.   Tenant shall not waste electricity, water or air-conditioning and shall
cooperate fully with Landlord to assure the most effective and efficient
operation of the Building's heating and air-conditioning systems.

9.   No locks or similar devices shall be attached to any door except by
Landlord and Landlord shall have the right to retain a key to all such locks
except for such secured areas as were established in connection with the Prior
Lease or which may be established by mutual consent of the parties hereto.
Tenant may not install any locks without Landlord's prior approval.

10.  Tenant assumes full responsibility of protecting the Premises from theft,
robbery and pilferage; the Indemnitees shall not be liable for damage thereto or
theft or misappropriation thereof.  Except during Tenant's normal business
hours, Tenant shall keep all doors to the Premises locked and other means of
entry to the Premises closed and secured.  All corridor doors shall remain
closed at all times.  If Tenant desires telegraphic, telephones, burglar alarms
or other electronic mechanical devices, the Landlord will, upon request direct
where and how connections

                              EXHIBIT C - Page 1
<PAGE>

and all wiring for such services shall be installed and no boring, cutting or
installing of wires or cables is permitted without Landlord's prior consent,
which shall not be unreasonably withheld.

11.  Except with the prior approval of Landlord (other than in connection with
the provisions of Section 9.01), all cleaning, repairing, janitorial,
decorating, painting or other services and work in and about the Premises shall
be done only by authorized Building personnel.

12.  The weight, size and location of safes, furniture, equipment, machines and
other large or bulky articles shall be subject to Landlord's approval and shall
be brought to the Building and into and out of the Premises at such times and in
such manner as the Landlord shall direct and at Tenant's sole risk and cost.
Prior to Tenant's removal of any of such articles from the Building, Tenant
shall obtain written authorization of the Office of the Building and shall
present such authorization to a designated employee of Landlord.

13.  Tenant shall not overload the safe capacity of the electrical wiring of the
Building and the Premises or exceed the capacity of the feeders to the Building
or risers.

14.  To the extent permitted by law, Tenant shall not cause or permit picketing
or other activity which would interfere with the business of Landlord or any
other tenant or occupant of the Building, or distribution of written materials
involving its employees in or about the Building, except in those locations and
subject to time and other limitations as to which Landlord may give prior
written consent.

15.  Tenant shall not cook, otherwise prepare or sell any food or beverages in
or from the Premises or use the Premises for housing accommodations or lodging
or sleeping purposes except that Tenant may install and maintain vending
machines, coffee/beverage stations and food warming equipment and eating
facilities for the benefit of its employees or guests, provided the same are
maintained in compliance with applicable laws and regulations and do not disturb
other tenants in the Building with odor, refuse or pests.

16.  Tenant shall not permit the use of any apparatus for sound production or
transmission in such manner that the sound so transmitted or produced shall be
audible or vibrations therefrom shall be detectable beyond the Premises; nor
permit objectionable odors or vapors to emanate from the Premises.

17.  No floor covering shall be affixed to any floor in the Premises by means of
glue or other adhesive without Landlord's prior written consent.

18.  Tenant shall at all time maintain the window blinds in the lowered
position, though Tenant may keep the louvers open.

19.  Except as set forth in Section 7.01(a) of the Lease, Tenant shall only use
the freight elevator for mail carts, dollies and other similar devices for
delivering material between floors that Tenant may occupy.

                              EXHIBIT C - Page 2
<PAGE>

20.  No smoking, eating, drinking, loitering or laying is permitted in the
Common Area except in designated areas.

21.  Landlord may require that all persons who enter or leave the Building
identify themselves to security guards, by registration or otherwise.  Landlord,
however, shall have no responsibility or liability for any theft, robbery or
other crime in the Building.  Tenant shall assume full responsibility for
protecting the Premises, including keeping all doors to the Premises locked
after the close of business.

22.  Tenant shall comply with all safety, fire protection and evacuation
procedures and regulations established by Landlord or any governmental agency
and shall cooperate and participate in all reasonable security and safety
programs affecting the Building.

                              EXHIBIT C - Page 3
<PAGE>

                                   EXHIBIT D

                            CLEANING SPECIFICATIONS
                            -----------------------

Time of Cleaning
----------------

     The cleaning operations shall be performed on a five (5) days per week
     basis after normal business hours, Monday through Friday, excluding
     holidays.:

Lobby Areas - Elevators
-----------------------

     1.   Floor of entrance lobby to be swept and washed as required.

     2.   Floors in elevator cars to be vacuumed, swept or washed nightly.

     3.   Lobby walls to be washed down when necessary.

     4.   Clean lobby lights, globes and fixtures when necessary.

Washrooms
---------

     1.   All floors to be damp mopped and thoroughly cleaned nightly using a
          dust control method.

     2.   Toilet seats, bowls, urinals and washbasins to be cleaned and
          disinfected nightly.

     3.   All body contact points in washrooms, such as water taps, receptacles
          and dispensers, door plates and flush valves to be disinfected and
          polished nightly.

     4.   Flush tanks, dispensers, receptacles, mirrors, shelves and all exposed
          piping to be dusted and cleaned nightly.

     5.   Sani-cans to be emptied, washed and disinfected sanibags replaced
          nightly.

     6.   Waste paper to be removed nightly.

     7.   Paper receptacles to be washed and disinfected weekly.

     8.   All toilet bowls and urinals to be descaled weekly.

     9.   Soap containers, toilet paper, towel dispensers and sanitary napkin
          dispensers to be replenished daily.

     10.  Toilet partitions to be cleaned daily.

                              EXHIBIT D - Page 1
<PAGE>

Office Areas - Nightly Service
------------------------------

     1.   All ash trays and smoking stands to be emptied, washed and polished.

     2.   All waste receptacles will be emptied and cleaned.

     3.   Drinking fountains will be washed and polished and all metal bright
          work will be kept in a clean condition.

Office Areas - Periodic Service
-------------------------------

     1.   Dusting of all furnishings and fixtures

     2.   Handmarks to be removed from partition and entrance door glass, doors,
          frames and walls where the finished surface permits as required.

     3.   Fabric covered furnishings will be brushed or vacuumed to remove all
          dust and dirt as required.

     4.   All carpeted areas will be vacuumed daily.

     5.   All telephones to be damp wiped monthly.

     6.   High dusting (above arm's reach) will be done once per month.

     7.   Hard surfaced floors to be maintained in a clean and polished
          condition by any of the following methods using top quality, anti-slip
          floor materials:

          a)   Strip and rewax quarterly.

          b)   Spray buff as required but not less than weekly.  Strip and rewax
               annually.

          c)   Light mop and rewax as required but not less than monthly.  Strip
               and rewax annually.

     8.   All vertical surfaces of furniture to be damp wiped once per week.

     9.   All window sills to be damp wiped once per week.

     10.  Air diffusers will be cleaned twice per year.

     11.  Venetian blinds will be dusted quarterly.

                              EXHIBIT D - Page 2
<PAGE>

                                   EXHIBIT E

                HEATING, VENTILATING AND AIR-CONDITIONING SYSTEM
                ------------------------------------------------

The Heating, Ventilating and Air-Conditioning (HVAC) system is designed to
maintain an interior temperature of 75 degrees Fahrenheit (dry bulb, 50 percent
relative humidity) when outdoor summer temperature is 94 degrees Fahrenheit (dry
bulb) - 72 degrees Fahrenheit (wet bulb) and 72 degrees Fahrenheit (dry bulb, 20
percent relative humidity, this is a reference only, no humidity is added to the
air by the building) when outdoor winter temperature is -10 degrees Fahrenheit
(dry bulb). This is based on an average occupancy density of not more than one
(1) person per 150 to 180 square feet of usable area and an average electrical
load of 3.5 watts per square foot of usable area.

The air distribution system consists of dual floor-by-floor air handling units
with variable air volume distribution and plenum air return. A separate air
handler serves the window wall and the interior spaces.

For floors 6-37 at the exterior curtain walls, perimeter heating and cooling is
by means of thermostat regulated variable air volume (V.A.V.) boxes. Floors 1 -
5 have electric baseboard heat with metal enclosure at perimeter exterior wall.

The interior zone cooling is by means of V.A.V. boxes. Thermostats, one per
V.A.V. box, are spaced approximately one per 1,200 square feet of usable floor
area of the premises.

The fan room on each floor has central chilled water plant supplying two-(2) air
handling systems for each floor.

Variable volume air distribution with slot-type diffusers on the perimeter and
perforated or slot diffusers in the interior.

The system design allows for the maximum utilization of "free cooling", the
ability to maintain comfortable environmental conditions without operating the
central cooling plant.

Cooling tower water is available year round for tenant's auxiliary cooling
requirements at an additional cost to tenant and subject to available capacity.

Given these design parameters, the building is operated under ASHRAE standards.

                               EXHIBIT E - Page 1
<PAGE>

                                   EXHIBIT F

                           BASE  BUILDING CONDITIONS
                           -------------------------

Landlord shall deliver the applicable space to Tenant in the condition outlined
below at Landlord's sole cost and expense:

1) General - Premises are accepted "as-is"

 .  To the extent available, the Landlord will supply Tenant plans representing
   the existing condition of the premises.
 .  Landlord will comply with ADA requirements in all common areas of the
   building.
 .  Locking devises and closers for all common area exits, stairwells,
   electrical/telephone closets and mens/women toilets. Tenant, at its cost may
   install combination locks on all toilet entrance doors on floors where the
   Tenant is a full-floor tenant.

2) Major damage to walls not being removed by the Tenant will be repaired at the
   expense of the Landlord.

3) The Landlord will contribute up to $1.00 per square foot, but not more than
   the actual cost per square foot, to achieve floor leveling to within 1/4 inch
   per 10 lineal feet non-cumulative. In the event the Tenant elects to level
   any area less than the entire demised expansion space being leased, open and
   free of partitions, the Tenant agrees at the expiration of the term, at the
   Landlord election, to remove the leveling material, unless such leveling is
   necessary to bring a small portion of the area up to the existing grade level
   (ie., if there is an area of indentation or sunken space, such space shall be
   raised to existing grade level).

4) Landlord will provide air for the premises for ventilation purposes of not
   less than 1.04 cfm per usable square foot of floor area or .89 cfm per
   rentable square foot of floor area.

                               EXHIBIT F - Page 1
<PAGE>

                                   EXHIBIT G

                    MAJOR CATEGORIES FOR OPERATING EXPENSES
                    ---------------------------------------

1.  Utilities
2.  HVAC contract and materials
3.  Repairs and Maintenance
4.  Janitorial and cleaning
5.  Security
6.  Landscaping
7.  Tenant relations
8.  Administration
9.  Management Fee
10. Insurance

Landlord will supply sufficient detail for each major category, including the
subcategories within each major category.  For example, utilities could have
subcategories which would include gas, water, electric, and sewer.

Additionally, Landlord will indicate the monthly building occupancy for the
calendar year.  Attached is a sample billing prepared by Landlord's Building
Manager, (including all referenced footnotes to the billing statement).

Notwithstanding anything contained in this Lease to the contrary, Landlord shall
be permitted to change the account structure if Landlord changes its chart of
accounts or method of accounting, so long as the level of detail does not
change.

                               EXHIBIT G - Page 1
<PAGE>

                                   EXHIBIT H

                            CATEGORIES FOR REMOVAL
                            ----------------------

1.   Additional HVAC and all related electrical wiring, conduit and other
related electrical hardware, and ductwork specifically installed for the unit,
except for supplemental equipment currently contained in the telecom rooms.

2.   Any vaults or similar installation.

3.   All Electrical conduit larger than 3/4 inch that is not used for standard
lighting and office use.  In addition to the conduit, all related connectors,
boxes and switchgear will be removed.

4.   All raised floors.

5.   Stairwell (if any).

6.   Generator (if any).

7.   Roof Top communication and all related wiring (if any).

8.   Close all floor, ceiling and roof openings, and close any staircases or
other openings between floors (if any).

9.   If any of the Tenant Additions which were installed by Tenant involved the
lowering of ceilings, raising of floors or the installation of specialized wall
or floor coverings or lights, then Tenant shall also be obligated to return such
surfaces to their condition prior to the commencement of this Lease.   Tenant
shall also be required to close any staircases or other openings between floors.

                               EXHIBIT H - Page 1
<PAGE>

                                   EXHIBIT I

                          SATELLITE LICENSE AGREEMENT
                          ---------------------------

     This License Agreement ("Agreement") is made and entered into as of this
________ day of _______, 20___, by and between METROPOLITAN LIFE INSURANCE
COMPANY, a New York corporation ("Licensor") and THE NORTHERN TRUST COMPANY, a
national banking corporation ("Licensee").

                                  WITNESSETH:

     WHEREAS, Tenant leased certain premises in 10 South LaSalle Street,
Chicago, Illinois (the "Building") pursuant to that certain Lease dated December
___, 2000 (the "Lease"), the premises being more particularly described therein
(the "Premises").

     WHEREAS, Tenant desires to install a Satellite System;

     WHEREAS, Landlord is willing to permit such installation under the
following terms and conditions;

     NOW THEREFORE, in consideration of the mutual covenants and agreements
herein contained and for other good and valuable consideration, the receipt and
adequacy of which is hereby acknowledged by both parties, the parties agree as
follows:

1.   Definitions.  Licensor and Licensee agree that the respective terms as used
     -----------
herein shall, unless the context otherwise requires, have the following
meanings:

     "Building" - that certain office building located at 10 South LaSalle
Street, Chicago, Illinois 60603.

     "Antenna Site" - the applicable portions of the roof and equipment areas
of the Building designated by Licensor as the location for Site Equipment
(hereinafter defined). The Antenna Site is located in the area depicted on
Exhibit A attached hereto. Notwithstanding the foregoing, Licensor shall be
entitled to cause Licensee to relocate its Site Equipment from the Antenna Site
to a comparable space (a "Relocation Space") at any time upon reasonable notice
to Licensee (which notice shall not be given in excess of ninety (90) days prior
to such relocation) and Licensee agrees to relocate its Site Equipment at
Licensor's sole expense.

     "Site Manager" ___________________________, or any other entity designated
by Licensor to manage the Antenna Site during the term of this agreement.

     "Site Equipment" means any "receive only" communications equipment,
including satellite dishes, base stations, antenna(s), poles, dishes or masts,
cabling or wiring and accessories used therewith approved by Licensor for
installation, operation and maintenance on the Antenna Site,

                               EXHIBIT I - Page 1
<PAGE>

and, as of the date of this Agreement, specifically includes those items on
Exhibit B attached hereto.

     Licensor and Licensee agree that capitalized terms defined elsewhere in
this Agreement shall, unless the context requires otherwise, have the meaning
there given. Licensor and Licensee shall act in good faith in the performance of
their respective obligations under this Agreement and, unless otherwise
expressly provided, shall not unreasonably withhold, and shall act as promptly
as is reasonably practicable under the circumstances in granting or denying, any
consent or approval required hereunder.

2.   Grant of License.  Licensor is the owner of the Building.  Licensee is a
     ----------------
tenant in the Building and occupies certain space in the Building pursuant to
the terms of a lease dated December _____, 2000 (the "Lease").  Licensee desires
to install Site Equipment on the Antenna Site.

     Subject to the terms and conditions of this Agreement, Licensor hereby
grants to Licensee a non-exclusive and non-assignable license (except to an
Affiliate of Tenant as defined in the Lease and/or as set forth below), for the
term of this Agreement (as such term may be extended or renewed), to install,
maintain and operate the Site Equipment, at the sole cost and expense of
Licensee, subject to Licensor's approval in all respects.  The Site Equipment
shall be solely for the use of Licensee. Licensee is specifically prohibited
from selling, reselling, or distributing services associated with the Site
Equipment to a third party.  Licensee acknowledges that Licensor has previously
granted rights to use the roof of the Building and risers to others and that the
rights granted to Licensee hereunder are expressly subject and subordinate to
the rights previously granted to others, whether or not such others have
exercised such rights as of the date of this Agreement and the Site Equipment
shall not interfere with any rooftop equipment now or hereafter installed
pursuant to any such rights. Licensor shall use reasonable efforts to prevent
any other rooftop equipment now or hereafter installed from interfering with the
Site Equipment.  Licensee further acknowledges that Licensor shall have the
right hereafter to grant similar or other rights to third parties to use the
roof or other space at the Building for antennae, antenna dish or other devices
for the reception or transmission of communications, data or other signals.

     Notwithstanding anything to the contrary contained in this Agreement,
Licensee's rights hereunder shall not be affected by any sublease of the
Premises entered into pursuant to the terms of the Lease.  In addition, the
right under this License shall be automatically transferred to an Assignee who
leases the entire Premises pursuant to the terms of this Lease and may be (at
Licnesor's discretion, be transferred to any Assignee pursuant to an Assignment
of the Lease for more than 25% of Licensee's then leased space in the Building,
but shall not be transferred to any Assignee pursuant to an Assignment of the
Lease for less than 25% of Licensee's then leased space in the Building.

3.   Plans.  Prior to the installation of the Site Equipment, Licensee shall
     -----
deliver to Licensor, for its review and approval, a set of plans and
specifications for the Site Equipment, which shall include, without limitation,
satellite dish design, size, floor and power load requirements, cabling
installations the means of affixing the satellite dish, and the means of
connecting the Site Equipment to the Building's electrical system and to the
Leased Premises. The satellite dish(es)

                               EXHIBIT I - Page 2
<PAGE>

shall be receive-only and will have a non-penetrating mast mount design unless
required by Laws. Licensee shall deliver to Licensor such additional information
as may be requested by Licensor from time to time.

4.   Installation.  The Site Equipment and its installation, maintenance and
     ------------
operation, shall comply with all applicable laws, ordinances and regulations.
Prior to the installation and operation of the Site Equipment by Licensee,
Licensee shall, at its sole cost and expense, obtain all necessary licenses,
permits and approvals from all governmental agencies having jurisdiction.  The
Site Equipment shall be installed and maintained by contractors acceptable to
Licensor, in accordance with the approved plans and specifications and in
compliance with all requirements of Licensor.

5.   Interference.  If, in the sole judgment of Licensor, any electrical,
     ------------
electromagnetic, radio frequency or other interference shall result from the
operation of any of Licensee's Site Equipment, Licensee agrees that Licensor
may, at Licensor's option, shut down Licensee's equipment upon not less than
eight (8) business hours prior verbal notice to Licensee; provided, however that
if an emergency situation exists, which Licensor reasonably determines in its
sole discretion to be attributable to Licensee's equipment, Licensor may
immediately notify Licensee verbally, who shall act immediately to remedy the
emergency situation.  Should Licensee fail to so remedy said emergency
situation, Licensor may then act to shut down Licensee's Site Equipment.
Licensee shall indemnify and defend Licensor and hold it harmless from all
expenses, costs, damages, loss, claims or other liabilities arising out of said
shutdown.  Licensee agrees to cease operations (except for intermittent testing
on a schedule approved by Licensor) until the interference has been corrected to
the satisfaction of Licensor.  If such interference has not been corrected
within 60 days (which correction may include a change of Site Equipment in
accordance with the terms hereof), Licensor may, at its sole option, either
terminate this Agreement forthwith, or may require that Licensee immediately
remove from the Antenna Site the specific item of Site Equipment causing such
interference, in which latter case the Monthly License Fee shall be reduced by
the portion of the fee applicable to such equipment for the remainder of the
Term and all other terms and conditions of this Agreement shall remain in full
force and effect.

6.   Electricity.  Licensee shall be responsible for the cost of supplying
     -----------
electricity to the Site Equipment.  Electric usage shall be determined, at
Licensor's option, either (a) by meters installed by Licensor at Licensee's sole
cost and expense, or (b) by Licensor's reasonable estimate.  Licensee shall pay
Licensor monthly, within fifteen (15) days of being billed therefor, for all
electricity used in connection with the operation of the Site Equipment.

7.   Access.  Licensee or Licensee's agents shall have the right to enter those
     ------
parts of the Building outside the premises leased to Licensee under the Lease
which are reasonably necessary for the installation, maintenance and removal of
the Site Equipment in the event of an emergency (under such regulations as
Landlord prescribes for security purposes) or, after twenty-four (24) hours
advance notice to Licensor and the opportunity to have a representative present.

8.   Maintenance.  Licensee shall keep its Site Equipment, the Antenna Site and
     -----------
the areas immediately surrounding same neat and clean.  Licensee shall conduct
its business and control its agents, employees, invitees and visitors in such
manner as not to create any nuisance, or interfere with, annoy or disturb any
other licensee or tenant of the Building or Licensor in its operation of the

                               EXHIBIT I - Page 3
<PAGE>

Building (including the Antenna Site).  Licensor shall have no obligation to
license, maintain, operate or safeguard the Site Equipment.

9.   Mechanic's Liens.  Licensee will not permit any lien or claim for lien of
     ----------------
any mechanic, laborer or supplier or any other lien to be filed against the
Antennae Site in accordance with the provisions of Section 9.02 of the Lease.

10.  License Fee.  During the term of this Agreement, Licensee shall pay to
     -----------
Licensor a license fee in the amount of _______________($____) per month.  The
license fee shall be (a) payable in advance on the first day of each and every
calendar month during the term of this Agreement, without deduction or set off;
and (b) prorated for any partial calendar month at the beginning or end of the
term based upon the number of days in the applicable month.  The pro rated
license fee for the partial month at the beginning of the term, if any, shall be
due and payable on the date of this Agreement. Licensor hereby agrees that the
license fee shall not exceed the average rates charged by office buildings
comparable to the Building in the Chicago West/Central Loop office market.

11.  Term.  The term of this Agreement shall begin on ___________, and shall end
     ----
on the earlier of (a) ________________, or (b) the date on which the Lease
terminates and shall be extended if the Term of the Lease is extended.

12.  Indemnification.  Licensee agrees to indemnify, defend and hold harmless
     ---------------
Licensor, its agents, employees and partners, from and against any and all
claims, suits, actions, liabilities, damages and/or expenses (including, without
limitation, attorney's fees and court costs) arising from or in connection (a)
the negligence or willful misconduct of Licensee, its agents, employees or
contractors; or (b) the exercise by Licensee of any of its rights under this
Agreement; or (c) the failure by Licensee to perform any of its obligations
under this Agreement.

13.  Insurance.  At all times that this License is in effect, Licensee, at its
     ---------
sole expense, shall obtain and keep in force insurance in accordance with the
provisions of Article Sixteen.

14.  Removal.  At the end of the term of this Agreement, or upon the earlier
     -------
termination of Licensee's rights hereunder, Licensee shall, at its sole cost and
expense, remove the Site Equipment in a manner satisfactory to Licensor, and
otherwise restore and repair the affected area of the roof and other parts of
the Building to the same condition as existed immediately prior to the
installation of the Site Equipment, normal wear and tear excepted.  Such
removal, restoration and repair shall be performed by a contractor, and in a
manner, acceptable to Licensor.  Notwithstanding the foregoing, Licensor may, at
its election, perform such removal, restoration and repair work for Licensee, in
which case Licensee shall, within fifteen (15) days of being billed therefor,
pay all costs and expenses incurred by Licensor in connection with such work or,
at Licensor's sole option, such Site Equipment shall be conclusively presumed to
have been abandoned by Licensee and may become the sole property of Licensor.

15.  Damage to Building.  Licensee shall be solely responsible for all costs
     ------------------
incurred by Licensor to repair any damage to the Building resulting from the
installation, operation, maintenance or removal of the Site Equipment.  Licensee
shall pay Licensor for such costs upon demand.

                               EXHIBIT I - Page 4
<PAGE>

16.  Default and Licensor's Remedies.  The (i) failure of Licensee to perform
     -------------------------------
any of its covenants contained in this Agreement and the continuation of such
failure for five (5) days after notice from Licensor to Licensee (except with
                 ---
respect to the provisions of Section 5 of this Agreement)and/or (ii) Default by
Licensee of its obligations under the Lease shall constitute an event of default
hereunder, upon the occurrence of which, Licensor shall have, in addition to all
remedies available at law or equity, the right to terminate this Agreement and
remove the Site Equipment at the sole cost and expense of Licensee.

17.  No Assignment; Binding Agreement.  Licensee may not transfer, sublease, or
     --------------------------------
assign all or any part of its interest under this Agreement, except as set forth
in Section 2 above, without the prior written consent of Licensor.  Subject to
the preceding sentence, this Agreement shall be binding upon and inure to the
benefit of the parties hereto and their respective successors and assigns.

18.  Entire Agreement.  This Agreement represents the entire agreement between
     ----------------
the parties hereto and there are no collateral or oral agreements of
understandings.  This Agreement shall not be modified in any manner except by an
instrument in writing executed by the parties to this Agreement.

19.  Survival.  Any and all agreements set forth in this Agreement which, by its
     --------
or their nature, would reasonably be expected to be performed after the
expiration or earlier termination of this Agreement shall survive and be
enforceable after the expiration or earlier termination of this Agreement.

20.  Miscellaneous.
     -------------

     a.   Licensor makes no representations or warranties as to the suitability
or effectiveness of the Antenna Site, or as to any governmental requirements
applicable thereto.

     b.   Nothing in this Agreement shall be construed to make the roof and/or
Building systems part of the premises leased to Licensee pursuant to the Lease
for any purpose; nor shall this Agreement be construed to require any services
from Licensor with respect to the roof or Building systems by reason of the
existence of the Site Equipment.

     c.   Licensee  hereby indemnifies and holds Licensor harmless against any
loss, claim, expense or liability with respect to any commissions or brokerage
fees claimed on account of the execution and/or renewal of this Agreement due to
any action of Licensee

21.  Limitation of Licensor's Personal Liability.  In no event shall Licensor be
     -------------------------------------------
liable to Licensee for (a) any loss or damage that may be occasioned by or
through the acts or omissions of other tenants or licensees of the Building or
of any other persons whomsoever or (b) any incidental, indirect, special,
consequential, punitive or reliance damages of any nature whatsoever regardless
of the foreseeability thereof (including but not limited to, any claim from any
client, customer or patron for loss of service, lost profits or lost revenues)
arising under or in connection with this Agreement or the performance
thereunder, from any breach or partial breach or potential breach of the
provisions of this Agreement or arising out of any act or omission by Licensor,
its employees,

                               EXHIBIT I - Page 5
<PAGE>

servants or agents whether based on breach of contract, breach of warranty,
negligence or any other theory of liability. Nothing contained in the
immediately preceding sentence shall ever be construed as creating liability in
excess of that existing at law or, in any event, increasing the liability of
Licensor under any theory or cause of action, however denominated, from that
existing at law. Further, the liability of Licensor to Licensee for (a) any
default by Licensor under the terms of this Agreement, (b) any tort liability of
Licensor to Licensee, or (c) in any other circumstance in which Licensor is
judicially determined to have some liability to Licensee, for whatever reason,
shall, in each such instance, be limited to the interest of Licensor in the
Building and Licensee agrees to look solely to Licensor's interest in the
Building for the recovery of any judgment from Licensor, it being intended that
Licensor shall never be personally liable for any judgment or deficiency.
Notwithstanding anything to the contrary herein, Licensee agrees, on its behalf
and on behalf of its successors and assigns, that any liability of Licensor with
respect to this Agreement shall never exceed the amount of $10,000,000 and
Licensee shall not be entitled to any judgement in excess of that amount.

22.  Notices.  All notices given in connection with this Agreement shall be in
     -------
writing and shall be addressed as set forth in the Lease.

     Any such notice shall be sufficient if sent by registered or certified
mail, return receipt requested, postage prepaid; by prepaid overnight delivery
service; or by personal delivery.  Either party may, by notice to the other
party given in accordance with this Section, change the address to which notice
is to be sent.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date aforesaid.

LICENSEE: THE NORTHERN TRUST COMPANY

By:  ___________________________________
Its: ___________________________________

LICENSOR: METROPOLITAN LIFE INSURANCE COMPANY,

By:  ________________________________
Its: ________________________________

                               EXHIBIT I - Page 6
<PAGE>

                                   Exhibit A

                                      To
                               Agreement Between
                      Metropolitan Life Insurance Company
                                      And
                          The Northern Trust Company.

                         Site Equipment Specifications

                               EXHIBIT I - Page 7
<PAGE>

                                   Exhibit B

                                      To
                               Agreement Between
                      Metropolitan Life Insurance Company
                                      And
                          The Northern Trust Company

                                 Antenna Site

                               EXHIBIT I - Page 8

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