Document:

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                                               Exhibit 10.15
                                               Chicago Mercantile Exchange, Inc.
                                              Registration Statement on Form S-4

                  Building:      10 SOUTH WACKER DRIVE
                           ---------------------------------

                               CHICAGO, ILLINOIS

                                     LEASE

        AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, AS TRUSTEE
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                                    LANDLORD

                          CHICAGO MERCANTILE EXCHANGE,

                     An Illinois not-for-profit corporation
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                                     TENANT

          175,660 Square Feet on the 2nd through 10th Floors inclusive
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                                    PREMISES

                                 March 31, 1988
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                                 DATE OF LEASE
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                               Table of Contents

Section                           Title                               Page
-------                           -----                               ----
  1                   Lease of Premises and Term                        1
  2                   Base Rent                                         1
  3                   Rent Adjustments                                  1
  4                   Service                                           4
  5                   Condition of Premises                             5
  6                   Commencement of Base Rent and Rent Adjustments    5
  7                   Use of Premises                                   6
  8                   Care and Maintenance                              8
  9                   Alterations and Construction                      8
  10                  Access to Premises                                9
  11                  Untenantability                                   10
  12                  Insurance                                         10
  13                  Eminent Domain                                    11
  14                  Assignment-Subletting                             12
  15                  Waiver of Claims and Indemnity                    13
  16                  Mortgage-Ground Lease                             14
  17                  Certain Rights Reserved to Landlord               15
  18                  Holding Over                                      15
  19                  Remedies of Landlord                              16
  20                  Intentionally Omitted                             17
  21                  Surrender of Possession                           17
  22                  Notices                                           18
  23                  Intentionally Omitted                             18
  24                  Intentionally Omitted                             18
  25                  Registered Agent                                  19
  26                  Miscellaneous                                     19
  27                  Tenant Credit                                     22
  28                  Intentionally Omitted                             24
  29                  Intentionally Omitted                             24
  30                  Signage                                           25
  31                  Antenna Option                                    27
  32                  Intentionally Omitted                             30
  33                  Obligation of Landlord to Repair and Maintain     30
  34                  Secured Area (s)                                  30
  35                  Parking                                           31
  36                  Insurance of Landlord                             31
  37                  Vault                                             32
  38                  Access to Trading Floors                          32

                             continued on page (b)

                                      (a)
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  Continued from page (a)

Section                           Title                               Page
-------                           -----                               ----
  39                  Non-Disturbance and Attornment Agreement          33
  40                  Quiet Enjoyment                                   33
  41                  Intentionally Omitted                             33
  42                  Compliance with Laws                              33
  43                  Security Service                                  33
  44                  Renewal Option                                    34
  45                  Printing Facility                                 35
  46                  Escalator Option                                  36
  47                  Telecommunications Closet Option                  38
  48                  Expansion Options                                 40
  49                  Intentionally Omitted                             44
  50                  Right of First Offering                           44
  51                  Bathroom Facilities                               46
  52                  Elevators                                         48
  53                  Concurrent Exercise of Options                    48
  54                  Landlords Execution of Documents                  49

  Exhibit                                Title
  -------                                -----
  A-1                 Chicago Mercantile Exchange - Floor 2
  A-2                 Chicago Mercantile Exchange - Floor 3
  A-3                 Chicago Mercantile Exchange - Floor 4
  A-4                 Chicago Mercantile Exchange - Floor 5
  A-5                 Chicago Mercantile Exchange - Floor 6
  A-6                 Chicago Mercantile Exchange - Floor 7
  A-7                 Chicago Mercantile Exchange - Floor 8
  A-8                 Chicago Mercantile Exchange - Floor 9
  A-9                 Chicago Mercantile Exchange - Floor 10
  B                   JMB/MS Management Company
                          Estimated Rent Adjustment Statement for 1988
  C                   Work Supplement
  D                   Base Building Construction
  E                   Night Janitor Schedule
  F                   Non-Disturbance and Attornment Agreement
  G-1                 Intentionally Omitted
  G-2                 Intentionally Omitted
  H                   Intentionally Omitted
  I                   Chicago Mercantile Exchange - Plaza Level
  J                   Signage Location Plan
  K-1                 Chicago Mercantile Exchange - Floor 3
  K-2                 Chicago Mercantile Exchange - Floor 4
  K-3                 Chicago Mercantile Exchange - Floor 5
  K-4                 Chicago Mercantile Exchange - Floor 6
  K-5                 Chicago Mercantile Exchange - Floor 7
  L-1                 Chicago Mercantile Exchange - Floor 2
  L-2                 Chicago Mercantile Exchange - Floor 3
  L-3                 Chicago Mercantile Exchange - Floor 4
  L-4                 Chicago Mercantile Exchange - Floor 5
  L-5                 Chicago Mercantile Exchange - Floor 6
  L-6                 Chicago Mercantile Exchange - Floor 7
  L-7                 Chicago Mercantile Exchange - Floor 8
  L-8                 Chicago Mercantile Exchange - Floor 9

                             continued on page (c)

                                      (b)
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  Continued from page (b)

  L-9                 Chicago Mercantile Exchange - Floor 10
  L-10                Chicago Mercantile Exchange - Floor M1
  M                   Building Standards
  N-1                 Intentionally Omitted
  N-2                 Intentionally Omitted
  O                   Intentionally Omitted
  P                   Advice
  Q-1                 Chicago Mercantile Exchange - Floor 3
  Q-2                 Chicago Mercantile Exchange - Floor 7

                                      (c)
<PAGE>

      THIS LEASE, made as of the 31st day of March, 1988, between AMERICAN
NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking association of
Chicago, Illinois, not individual but solely as Trustee under the provisions
of a certain Trust Agreement dated June 2, 1981 and known as the Trust No.
51234 ("Landlord"), and

             Chicago Mercantile Exchange,
             An Illinois not-for-profit corporation

("Tenant")

                                        WITNESSETH:

      1. Lease of Premises and Term. Landlord hereby leases to Tenant, and
Tenant accepts the demised premises being 175,660 square feet on the 2nd through
10th floors inclusive, ("Premises"), described on attached Exhibits "A-1"
through "A-9" inclusive, in the building known as 10 South Wacker Drive.
Chicago, Illinois ("Building") for the term of fifteen (15) years, eight (8)
months ("Term"), unless sooner terminated as provided herein, commencing April
1, 1988 ("Commencement Date") and ending November 30, 2003 ("Expiration Date"),
to be occupied and used by Tenant for FN 1.1. ("Use") and no other purpose,
subject to the agreements herein contained.

      2. Base Rent. Subject to the Installment Credits (defined in section 27.A
of this Lease), Tenant shall pay to JMB/MS Management Co. at 111 East Wacker
Drive, Suite 1200, Chicago, Illinois, or to such other person or at such other
place as Landlord may direct in writing, in lawful money of the United States of
America, the sum of FORTY-NINE MILLION TWENTY THOUSAND TWO HUNDRED SIXTY-SIX AND
80/100 Dollars. ($ 49,020,266.80) ("Base Rent") in one hundred eighty-eight
(188) equal monthly installments of TWO HUNDRED SIXTY THOUSAND SEVEN HUNDRED
FORTY-SIX AND 10/100 Dollars ($ 260,746.10) ("Installments") in advance on or
before the first day of each month of the Term (subject to Section 27.A.). Base
Rent shall be paid without any set-off or deduction except as expressly provided
in this Lease. Unpaid Base Rent shall bear interest at the rate and at the time
set forth in Section 26.F. Time is of the essence of this Lease. Landlord and
Tenant agree to do and perform each and every covenant, agreement and obligation
to be performed by each of them respectively hereunder.

      3. Rent Adjustments. In addition to Base Rent, Tenant shall make payments
in accordance with this Section 3.

         A.      For purposes of this Lease:
                 1.   "Base Year" means the calendar month of April, 1988.

                 2.   "Calculation Year" means any calendar year during the Term
                      (commencing with the calendar year in which the
                      Commencement Date occurs) for which a Rent Adjustment
                      computation is being made, FN 1.2.

FN 1.1. through FN 1.2. - see page 1(a)

                                       1
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FN 1.1. - continued from Section 1

general offices of a mercantile or commodity exchange or other exchange or other
general office uses.

FN 1.2. - continued from Section 3.A.2.

so that the first Calculation Year during the Term is the calendar year 1988
(the period commencing January 1, 1988 and ending December 31, 1988), the second
Calculation Year during the Term is the calendar year 1989 (the period
commencing January 1, 1989 and ending December 31, 1989) and so one during the
Term.

                                      1(a)
<PAGE>

        3. "Consumer Price Index" ("CPI") means the average of: a) U.S. City
Averages for all Urban Consumers, All Items, of the United States Bureau of
Labor Statistics: and b) U.S. City Averages for Urban Wage Earners and Clerical
Workers, All Items, of the United States Bureau of Labor Statistics. The CPI FN
2.1. calendar year shall be determined by first averaging the monthly indices
for each index and then averaging the two indices (All Items).

        4. "Expenses" means and includes: a) those expenses paid or incurred by
Landlord for maintaining, operating and repairing the Real Property, the cost of
electricity, steam, water, fuel, heating, lighting, air-cooling, window
cleaning, janitorial service, insurance, including, but not limited to, fire,
extended coverage, liability, worker's compensation, elevator, or any other
insurance carried in good faith by Landlord and applicable to the Real Property,
painting, uniforms, customary management fees, supplies, sundries, sales or use
taxes on supplies or services, cost of wages and salaries of all persons engaged
in the operation, maintenance and repair of the Real Property, and so-called
fringe benefits, including social security taxes, unemployment taxes, cost for
providing coverage for disability benefits, cost of any pensions,
hospitalization, welfare or retirement plans, or any other similar or like
expenses incurred under the provisions of any collective bargaining agreement,
or any other cost or expense which Landlord pays or incurs to provide benefits
for employees so engaged in the operation, maintenance and repair of the Real
Property, the charges of any independent contractor who, under contract with
Landlord or its representatives, does any of the work of operating, maintaining
or repairing the Real Property, legal and accounting expenses, including, but
not to be limited to, such expenses as relate to seeking or obtaining reductions
in and refunds of Taxes FN 2.2. or any other expense or charge, whether or not
hereinbefore mentioned, which in accordance with generally accepted accounting
and management principles would be considered as an expense of maintaining,
operating, or repairing the Real Property: and b) FN 2.3.

        5. "Real Property" means the Building, the land parcel upon which it
stands and the personal property used in conjunction with both.

        6. "Rent Adjustment" means any amount owed by Tenant attributable to
Expenses or Taxes or increases in CPI. The Rent Adjustment shall be paid in
addition to and in the same manner as Base Rent.

        7. "Rentable Area of the Building" is 946,356 square feet which is the
sum of the of the rentable area of all demised premises (leased or unleased) in
the Building on floors designated by Landlord as office floors.

        8. "Rentable Area of the Premises" is 175,660 square feet which: a) if
this Lease be for an entire floor, is the area inside the center line of the
exterior glass walls (except public stairs, elevator shafts, vertical piping and
pipe shafts, vertical air-supply, return and exhaust shafts or ducts): plus a
proportionate share of "Mechanical Spaces" (i.e. spaces housing servicing areas,
equipment, and/or access corridors for: heating, ventilating, air-cooling,
electrical, communications facilities, plumbing/fire protection, elevators or
engineer's offices) above the lobby floor, or b) if this Lease be for less than
an entire floor, is the area measured from the center line of the exterior glass
walls to the center line of the corridor or other demising partitions: plus i) a
proportionate share of: public areas (including corridors), toilets and janitor,
electrical and communication closets on the floor housing the Premises, and ii)
a proportionate share of Mechanical Spaces above the lobby floor. In either case
(a or b), no deduction is made for columns of Building projections.

FN 2.1. through FN 2.3. - see pages 2(a) - 2(c)

                                       2
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FN 2.1. - continued from Section 3.A.3.

for the Base Year shall be equal to the CPI for the calendar month April, 1988
and the CPI for any subsequent

FN 2.2. - continued from Section 3.A.4.

(which Landlord shall make reasonable efforts to obtain),

FN 2.3. - continued from Section 3.A.4.

the amortized portion of the cost of any capital improvement made to the Real
Property which is either (i) required by law, ordinance or governmental
regulation (including, without limitation, the cost of any modification or of
any system in the Building, or installation of additional systems, or
modification of the Building, or compliance with fire safety requirements, to
the extent any of the foregoing is required by law, ordinance or governmental
regulation), or (ii) intended by Landlord to reduce Expenses ("Included Capital
Items"), provided, however, that the portion of the annual amortized costs to be
included in Expenses in a calendar year with respect to a capital improvement
which is intended by Landlord to reduce Expenses, shall equal the lesser of: (i)
such annual amortized costs or (ii) the projected annual amortized reduction in
Expenses for that portion of the useful life of the capital improvement which
falls within the Term (based upon the total cost savings from such capitol
improvement for such period, as reasonably estimated by Landlord). Any
amortization required pursuant to the immediately preceding clause (b) shall be
in accordance with the generally accepted accounting principles and include
interest at the Prime Rate (Section 26.F.) in effect on the date of installation
if the capital improvement. If the Building is not fully occupied or if not all
of the tenants in the Building use a particular service during all or a portion
of any year, Landlord shall not make any adjustment of Expenses by reason of
such partial occupancy or partial use, except that Landlord may make an
appropriate adjustment of the cleaning and janitorial expense component of
Expenses for such year employing sound accounting and management principles to
determine the amount of cleaning and janitorial expenses that would have been
paid or incurred by Landlord if the Building had been fully occupied and all of
the tenants of the Building were cleaning and janitorial service and the amount
so determined shall be deemed to have been the cleaning and janitorial expenses
for such year; provided if Landlord's cleaning contractor gives Landlord a
credit against the cost of cleaning and janitorial services to account for space
that is not occupied and/or space that is occupied by a tenant that is not
receiving cleaning and janitorial service from Landlord's cleaning contractor,
then the amount of any such adjustment over actual cleaning and janitorial
expenses to account for any such space shall not exceed the amount of the credit
granted by Landlord's cleaning contractor with respect to such space. If any
Real Property expense , though paid in one year, relates to more than one
calendar year, if sound accounting principles dictate such expense shall be
proportionately allocated among such related calendar years. The term "Expenses"
shall not include:

        (i)    leasing commissions:
        (ii)   advertising and promotional expenditures:
        (iii)  cost of constructing and maintaining any leasing office located
               at the Building;

                                      2(a)
<PAGE>

        (iv) amounts paid on behalf of or reimbursed to Landlord through the
proceeds of insurance (provided that the amount of any reasonable deductible
paid by Landlord shall be included in Expenses), the proceeds of a condemnation
award of the proceeds of a recovery under a contractor's or other warranty, and
amounts that would have been paid on behalf of or reimbursed to Landlord through
the proceeds of insurance required pursuant to Section 36 of this Lease;

        (v) Amounts billed directly to tenants (whether or not collected by
Landlord) except through Rent Adjustments (escalation and Expense and Tax
payments) billed to tenants (including Tenant) in the Building:

        (vi) any expense in connection with services or benefits of a type which
are not available to Tenant or are only available to Tenant at an additional or
direct charge to Tenant, but which are provided to another tenant or occupant of
the Building (whether or not such expenses are billed or collected by Landlord);

        (vii) costs incurred in improving, decorating, renovating, or
redecorating any leasable space in the Building (including without limitation,
the cost of removing rubbish generated by any of the foregoing);

        (viii) depreciation, interest, and principal payments on mortgages, and
other debt costs (except to the extent that the same are attributable to
Included Capital Items) and ground lease payments.

        (ix) penalties for non-payment or late payment by Landlord of items
included in Expenses and costs due to the violation by Landlord or its agents if
any law, statute or ordinance; provided, however, that interest assessed against
Landlord for late payments relating to Taxes which are being (or had been)
contested in good faith in an appropriate manner by Landlord shall not be deemed
a penalty and shall be included in Expenses;

        (x) the costs of repairs or other restoration work to remedy damages
caused by negligence of Landlord, Landlord's beneficiaries or their respective
agents or employees;

        (xi) wages and salaried paid to any executive employee above the level
of Building manager;

        (xii) any portion of any cost allocable to any building other than the
Building; (xiii) accounting and other professional fees, attorney's fees, costs
and disbursements and other expenses incurred in connection with negotiations or
disputes with tenants or other occupants of the Building or with prospective
tenants (including, without limitation, the costs of defending claims made by
tenants against Landlord), or costs incurred in marketing the Building (except
that attorneys' and other professionals' fees, costs and disbursements and other
expenses incurred by Landlord in seeking to enforce Building rules and
regulations or in seeking to enforce the non-monetary obligations of any tenant
in the Building to the extent that such rules and regulations or non-monetary
obligations are intended to benefit the tenant population of the Building shall
be included in Expenses);

        (xiv) costs of a capital nature, excepting Included Capital Items
(Section 3.A.4.b.);

        (xv) any expense for correction of defects on the initial construction
of the Building or in the Systems (as defined in Section 9.A.) of the Building
(as opposed to the costs of normal repair and maintenance and replacement [to
the extent that such replacement does not constitute a capital improvement or
replacement] expected with the construction materials and the Systems installed
in the Building in light of their specifications);

                                      2(b)
<PAGE>

        (xvi) overhead and profit paid to subsidiaries or affiliates of Landlord
for services (except for property management fees) on or to the Building to the
extent that the charges for such services exceed competitive charges for such
services;

        (xvii) property management fees paid for any month in excess of the
greater of $15,000.00 and three percent (3%) of all rent receipts and other
revenues of the Building collected during such month; and

        (xviii)rental and other related expenses incurred in leasing
air-conditioning systems, elevators or other equipment ordinarily considered to
be of a capital nature, except (a) equipment which is used in providing
janitorial and maintenance service and which is not permanently affixed to the
Building, (b) equipment that is rented on a temporary basis for repairs or
maintenance, and (c) plants.

                                      2(c)
<PAGE>

        9. FN 3.1.

        10. "Taxes" means real estate taxes, assessments, sewer rents, rates and
charges, transit taxes, taxes based upon the receipt of rent, and any other
federal, state or local government charges, general, special, ordinary or
extraordinary (but not including income or franchise taxes or any other taxes
imposed upon or measured by the income or profits of Landlord. Unless the same
shall be imposed in lieu of real estate taxes), which may now or hereafter be
levied or assessed against the Real Property. In case of special taxes or
assessments which may be payable for in installments, only the amount of each
installment paid during a calendar year shall be included in Taxes for that
year. Taxes shall also include any personal property taxes (attributable to the
year in which paid) imposed upon the furniture, fixtures, machinery, equipment,
apparatus, systems and appurtenances used in connection with the Real Property
for the operation thereof. The amount of Taxes attributable to any calendar year
of the Term shall be in the amount of Taxes payable in such year,
notwithstanding that in each case the assessments for such Taxes may have been
made for a different year or years than the year in which payable.

        11. "Tenants Proportion" is 18.562% and means the sum derived by
dividing the Rentable Area of the Premises by the Rentable Area of the Building
and multiplying by one hundred (100).

        12. "Estimate" means the reasonable estimate by Landlord of CPI,
Expenses and Taxes based upon prevailing economic conditions. FN 3.2.

        B. FN 3.3.

           FN 3.4.

        C.1. Subject to Section 3.D. below, Tenant shall pay Landlord, a s a
Rent Adjustment for each calendar year during the Term, Tenant's Proportion of
Expenses.

        2. Subject to Section 3.D. below, Tenant shall pay Landlord, as a Rent
Adjustment for each calendar year during the Term, Tenant's Proportion of Taxes.

           FN 3.5.

        E. Tenant shall pay Landlord the Rent Adjustment Deposit I the same
manner as Base Rent, on the first day of each month during the Term commencing
with the Commencement Date. The Rent Adjustment Deposit shall be deposited
against Rent Adjustments due for the calendar year in which the Rent Adjustment
Deposits are to be paid. During the last complete calendar year or during any
partial calendar year in which the Expiration Date occurs. Landlord may include
in the Rent Adjustment Deposit its estimate of Rent adjustments which may not be
finally determined until after the Expiration Date.

        F. 1. On or before the Commencement Date, Landlord shall furnish Tenant
the Estimate and the Rent Adjustment Deposit for the calendar year in which the
Commencement Date occurs.

              2. As soon as reasonably feasible after the expiration of each
calendar year during the Term, Landlord will furnish Tenant a "Statement" FN
3.6. showing the following:

               a.  Expenses, Taxes, and CPI for the Calculation Year;

               b.  CPI - for the Base Year;

               c. The amount of Rent Adjustments due Landlord for the
                  Calculation Year, less credits for the Rent Adjustment
                  Deposits paid. if any. FN 3.7.7 and

               d. The Rent Adjustment Deposit due in the calendar year next
                  following the Calculation Year including the amount or revised
                  amount due for the months prior to the rendition of the
                  Statement.

        G. If the Commencement Date is not January 1st or if the Expiration Date
is not December 31st for the calendar years in which such Dates occur, Rent
Adjustments shall be prorated and be paid by Tenant within thirty (30) days
after billing. This covenant shall survive the Expiration Date.

FN 3.1. through FN 3.7. - see pages 3 (a) - 3(e)

                                       3
<PAGE>

FN 3.1. - continued from subsection 3.A.9.

"Rent Adjustment Deposit" for the calendar year in which the Commencement Date
occurs shall equal the Estimate of Landlord divided by twelve (12) and for each
calendar year thereafter during the Term, means the sum derived by dividing the
Rent Adjustments for the immediately preceding calendar year by the number of
months within the Term in such immediately preceding calendar year. (e.g., Rent
Adjustment Deposits for the calendar year 1990 shall equal the total amount of
Rent Adjustments due for the calendar year 1989, as reflected on the Statement
[Section 3.F.2.] for the calendar year 1989, divided by twelve [12], since all
twelve [12] months of the calendar year 1989 are in the Term). During the
calendar year in which a Statement is rendered (which Statement shall be for the
immediately preceding calendar year) and thereafter until a new Statement is
rendered, Tenant shall pay as its Rent Adjustment Deposit an amount (hereinafter
referred to as the "Deposit Amount") equal to the amount of the Rent Adjustments
shown in the Statement divided by the number of months within the Term in the
calendar year with respect to which the Statement was rendered. If the Rent
Adjustment Deposits paid during such calendar year prior to the rendering of the
Statement are less than or exceed the Deposit Amount, then the difference
multiplied by the number of months in such calendar year for which the Rent
Adjustment Deposit was paid prior to the rendering of this Statement, shall be
paid to Landlord by Tenant within thirty (30) days after the Statement is
rendered or shall be credited against amounts due from Tenant to Landlord under
this Lease as they become due (as the case may be), provided that if the Tenant
is entitled to such a credit, upon notice to Landlord, Tenant may request direct
payment of the excess (if any) of the amount to be credited over the sum of the
Installment of Base Rent and the Rent Adjustment Deposit next due after
rendering of the Statement, in lieu of a credit for such excess amount to Tenant
within thirty [30] days after receipt of such notice.

FN 3.2. - continued from subsection 3.A.12.

Tenant hereby acknowledges receipt of such Estimate attached hereto as Exhibit
"B" which shall be the Estimate for the First Calculation Year.

FN 3.3. - continued after subsection 3.A.12.

        13. "Holidays" means New Years Day, Memorial Day, Independence Day,
Labor Day, Thanksgiving Day and Christmas Day.

        14. "Force Majeure" means interruptions or delays caused by: war,
insurrection, civil commotion, riots, acts of God or the enemy, governmental
action, strikes, lockouts, picketing (legal or illegal), accidents, inability of
Landlord to obtain fuel, supplies or materials, or any other cause or causes
beyond the control of Landlord, but shall not include Landlord's lack of funds
or financing.

        15. "Acts of Tenants" means interruptions or delays caused by: acts,
defaults or omissions of Tenant, special work, changes, alterations or additions
required or made by Tenant in there layout or finish of the Premises or the
Building, the delay of Tenant in submitting plans, supplying information,
approving plans,

                                      3(a)
<PAGE>

specifications or estimates or giving authorizations or the request of Tenant
for items requiring long delivery periods.

        16. "30 South Wacker Building" located at 30 South Wacker Drive,
Chicago, Illinois, means the tower of the building immediately south of the
Building.

        17.  "Member(s)" means any of the following;

               A.  an individual; who is a member in good standing of Tenant; or

               B.  an entity (corporation or partnership) who:

                      1. has at least two (2) Chicago Mercantile Exchange seats
                         assigned to it, or

                      2. has at least two (2) International Monetary Market
                         seats assigned to it, or

                      3. has at least two (2) Index/Options Market seats
                         assigned to it, or

                      4. has been approved by Tenant as a Class B Clearing
                         Member.

        (Note: The International Monetary Market and the Index/Options Market
are divisions of Tenant.); or

               C. a person or entity  having  access to trading  rights
pursuant to a license or agreement with Tenant.

        18. "Trading Floors" means the trading floor, expansion floor and
interstitial spaces as shown on Exhibit "F" of the agreement dated as of July
22, 1981, called The Chicago Mercantile Exchange Center Easements, Reservations,
Covenants and Restrictions by and between American National Bank and Trust
Company of Chicago, as Trustee under Trust No. 48268, American National Bank and
Trust Company of Chicago, as Trustee under Trust No. 51234, American National
Bank and Trust Company of Chicago, as Trustee under Trust No. 51235, as amended
by an Amendment dated as of February 17, 1982, and a Second Amendment dated as
of December 14, 1983.

        19. "South Wacker Lease" means the lease dated May 11, 1981 by and
between American National Bank and Trust Company of Chicago, a national banking
association of Chicago, Illinois, not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980 and known as
Trust No. 48268 and Chicago Mercantile Exchange, an Illinois not-for-profit
corporation, as such Lease has been amended heretofore and as it may be amended
hereafter.

FN 3.4. - continued from subsection 3.B.

If the CPI for the Base Year is less than the CPI for any calendar year during
the Term, then Tenant shall pay Landlord, as a Rent Adjustment for such calendar
an amount equal to the product of the then current Rentable Area of the Premises
multiplied by $7.00 (as of the date of this Lease, such amount is $1,229,620.00

                                      3(b)
<PAGE>

[$ 7.00 X 175,660]) multiplied by the percentage of increase by which the CPI in
such calendar year exceeds the CPI for the Base Year.

FN 3.5. - continued after subsection 3.C.2.

D. Notwithstanding anything to the contrary contained in this Lease, the amount
of the portion of Rent Adjustments payable by Tenant attributable to the
combined amount of Expenses and Taxes (the "Expense/Tax Portion") shall be
limited ("Expense/Tax Cap") to the following maximum amounts during the
following periods (which shall collectively be referred to as the "Cap Period"):

        1. for the first twelve calendar months of the Term of this Lease
commencing on the Commencement Date (herein, such twelve calendar month period
and each successive twelve calendar month period thereafter is called a "Lease
Year"), the Expense/Tax Cap shall be $1,185,705.00 (6.75 x 175,660);

        2. for the second Lease Year the Expense/Tax Cap shall be in the amount
equal to the sum of $1,361,365.00 ($7.75 x 175,660), plus the amount of the
excess (if any) of the amount of the Expense/Tax Cap for the first Lease Year
over the amount of the Expense/Tax Portion payable by Tenant for such first
Lease Year;

        3. for the third Lease Year, the Expense/Tax Cap shall be in an amount
equal to the sum of $1,537,025.00 ($8.75 x 175,660), plus the amount of the
excess (if any) of the amount of the Expense/Tax Cap for the second Lease Year
over the amount of the Expense/Tax Portion payable by Tenant for such second
Lease Year;

provided, however, that on the event that any part of the Expense/Tax Portion
otherwise payable by Tenant during either of the first two (2) Lease Years is
not paid by Tenant due to the Expense/Tax Cap for such Lease Year, then such
unpaid part of the Expense/Tax Portion shall be paid as Expense/Tax Portion in
either or both of the second Lease Year and the third Lease Year to the extent
that the Expense/Tax Portion for such second and/or third Lease Year. For
example, if the Expense/Tax Portion is actually as follows:

               first Lease Year                    $ 1,195,705.00
               second Lease Year                     1,356,000.00
               third Lease Year                      1,530,000.00

Tenant will pay the following amounts as Expense/Tax Portion:

               First Lease Year                     $1,185,705.00
               Second Lease Year                     1,361,365.00
               Third Lease Year                      1,534,635.00

so that the amount by which the Expense/Tax Portion for the first Lease Year
exceeds the Expense/Tax Cap for the first Lease Year ($10,000.00) is paid in the
second Lease Year to the extent that Expense/Tax Portion for the second Lease
Year is less than the Expense/Tax Cap for the second Lease Year ($5,365.00) and
in the third Lease Year to the extent not paid in the second Lease Year
($4,635.00) since the Expense/Tax Cap for the third Lease Year exceeds the
Expense/Tax

                                      3(c)
<PAGE>

Portion for such Lease Year by more than the amount of the Expense/Tax Portion
remaining unpaid from the first Lease Year ($4,635.00).

        There will be no Expense/Tax Cap after the third Lease Year, provided
that if any part of the Expense/Tax Portion for any of the first, second or
third Lease Year remains unpaid after the application of the Expense/Tax Cap for
the third Lease Year, Landlord shall have no right to payment of such payment of
such unpaid part and such unpaid part shall not be carried forward and shall not
be due and payable in the fourth Lease Year or at any time thereafter, and
provided further, that: (i) if at anytime during the Cap Period payment of the
Expense/Tax Portion is totally abated pursuant to this Lease, the Cap Period
shall be suspended during the continuance of the abatement and shall resume
after the abatement is over and shall continue for a period of time equal to the
amount of time remaining in the Cap Period prior to the abatement (and
appropriate proportions shall be made in the amount of the Expense/Tax Portion
and the Expense/Tax Cap in the event a portion of the Cap Period is a partial
calendar year), and (ii) if at anytime during the Cap Period payment of the
Expense/Tax Portion is partially abated pursuant to this Lease, in proportion to
the untenantability of the Premises, the Expense/Tax Portion shall thereafter be
split for purposes of application of the Expense/Tax Caps and the Cap Period, in
accordance with the percentage of Expense/Tax Portion that is being abated (the
"Abated Percentage"). The Cap Period and the Expense/Tax Cap shall apply as
follows to the Payable Percentage of the Expense/Tax Portion: the Cap Period
shall remain the same and the Expense/Tax Caps shall continue to apply to such
Payable Percentage as set forth in Section 3.D.1. through 3.D.3. above, provided
that such Expense/Tax Caps shall be proportionately reduced to the Payable
Percentage of such Caps. There shall be no Expense/Tax Cap applicable to the
Payable Percentage of the Expense/Tax Portion after the third Lease Year. The
Cap Period and the Expense/Tax Cap shall apply as follows to the Abated
Percentage of the Expense/Tax Portion: the Cap Period shall be suspended during
the continuance of the abatement and shall resume after the abatement is over
and shall continue for a period of time equal to the amount of time remaining in
the Cap Period prior to the abatement (and appropriate prorations shall be made
in the amount of the Expense/Tax Portion and the Expense/Tax Cap in the event a
portion of the Cap Period is a partial calendar year), and the Expense/Tax Caps
applicable to such Abated Percentage shall not be proportionally reduced to the
Abated Percentage of such Caps. There shall be no Expense/Tax Caps applicable to
the Abated Percentage of the Expense/Tax Portion after the first three Lease
Years plus a period of time thereafter equal to the number of days during which
such Abated Percentage was abated. The Expense/Tax Caps shall not affect or
limit in any way the amount of the portion of the Rent Adjustments attributable
to increases in CPI.

FN 3.6. - continued from subsection 3.F.2.

(which has been audited by a Certified Public Accounting firm, and upon written
request from Tenant, Landlord shall provide Tenant with a copy of the auditor's
certification of the Expense amount reflected in the Statement)

                                      3(d)
<PAGE>

FN 3.7. - continued from subsection 3.F.2.c.

or, if the amount of the Rent Adjustment Deposits paid with respect to such
Calculation Year exceeds the amount of Rent Adjustments due, the Statement shall
show the amount of the credit to be applied to amounts due from Tenant to
Landlord under this Lease as they become due; provided, however, that (i) upon
notice to Landlord, Tenant may request direct payment of the excess (if any) of
the amount to be credited over the sum of the Installment of the Base Rent and
the Rent Adjustment Deposit next due after the rendering of the Statement, in
lieu of a credit for such excess amount, and Landlord, to the extent such
overpayment exceeds any amounts then due from Tenant to Landlord, shall remit
such excess amount to Tenant within thirty (30) days after receipt of such
notice; and (ii) any such overpayment reflected on a Statement delivered after
the Expiration Date shall be refunded to Tenant to the extent such overpayment
exceeds any amounts then due from Tenant to Landlord.

                                      3(e)
<PAGE>

        H. If the Bureau of Labor Statistics revises the manner in which the CPI
is determined, Landlord and Tenant shall agree upon an adjustment to the revised
index to 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 charge shall constitute a revision. If
the CPI becomes unavailable to the public because a publication is discontinued,
or otherwise. Landlord and Tenant shall agree upon a substitute therefore, which
shall be 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 publishing by
a major bank, other financial institution, university or recognized financial
publication.

        1. 1. Tenant may examine the records of Landlord supporting the
Statement (including Tax b) during normal business hours within ninety (90) days
after it is furnished. Unless Tenant takes written exception to any item within
one hundred twenty (120) days after the furnishing of the Statement (which shall
be noted on the item as "paid under protest"), such Statement shall be
considered as final and accepted by Tenant. Any amount due Landlord on the
Statement shall be paid by Tenant within thirty (30) days after it is furnished
FN 4.1.

               2. FN 4.2.

       4. Service

          A. Landlord, if Tenant is not in default under this Lease, shall
furnish (except to the extent restricted by law or governmental regulation).

               1. FN 4.3. Whenever Tenant uses heat generating machines,
equipment, lighting or has excessive population density which affect the
temperature otherwise maintained by the air-cooling system outside of the
Premises, Landlord reserves the right to install supplementary air conditioning
units in the Premises at the sole expense of Tenant. FN 4.5. Tenant shall pay
Landlord charges for a condenser water riser tap-in fee, (a one time fee of
$163.44 per gallon per minute), condenser water and the operation and
maintenance of the supplemental air conditioning system FN 4.6.

               2. Hot and cold water for use in Base Building lavatories, FN
4.7. If Tenant desires water in the Premises FN 4.8. cold water only shall be
supplied from City of Chicago mains drawn through a line, meter, and fixtures
installed by Tenant, at the expense of Tenant, with the consent of Landlord.
Tenant shall pay Landlord as additional Base Rent, at rates fixed by Landlord FN
4.9. charges for all water furnished in the Premises to plumbing fixture other
than Base Building fixtures if Tenant fails to pay the charges of Landlord for
water within twenty (20) days after billing, Landlord upon ten (10 days notice,
may in addition to any other remedy provided in this Lease, discontinue
furnishing water. No such discontinuance shall be deemed an eviction or
disturbance of the use by Tenant of the Premises or render Landlord liable for
damages or relieve Tenant from any obligation under this Lease;

              3. Passenger elevator service in common with Landlord and other
tenants, daily from 7:00 A.M. to 6:00 P.M. (Saturdays to 1:00 P.M.), Sundays and
Holidays excepted and freight elevator service in common with Landlord and other
Tenants daily from 7:00 A.M. to 5:00 P.M., Saturdays, Sundays and Holidays
excepted FN 4.10. Such normal elevator service, passenger or freight, if
furnished at other times shall be optional with Landlord and shall never be
deemed a continuing obligation, Landlord, however, shall provide limited
passenger elevator service daily at times at all times such normal passenger
service is not furnished. Operatorless automatic passenger and freight elevator
service shall be deemed "elevator service" within the meaning of this subsection
FN 4.11.

             4. Building Standard janitor and cleaning services in and about the
Premises in accordance with Exhibit "E", Saturday s, Sundays and Holidays
excepted. Tenant shall pay Landlord, charges for additional or extraordinary
janitorial or cleaning services in and about the premises FN 4.12.

FN 4.1. through FN 4.12. - see pages 4(a) - 4(c)

                                       4
<PAGE>

FN 4.1. - continued from Section 3.I.1.

If an audit by Tenant reveals an overcharge to Tenant in excess of five percent
(5%) of the total amount reflected on the Statement, Landlord shall pay the cost
of such audit.

FN 4.2. - continued from Section 3.I.2.

2. IN the event that another tenant in the Building takes a written exception to
the calculation of Expenses for a particular calendar year pursuant to, and
within the time permitted under such tenant's lease for doing so, and as a
result an error in the calculation of Expenses for such calendar year is
discovered that would affect the calculation of Tenant's Proportion of Expenses
for such calendar year, Landlord shall recalculate Tenant's Proportion of
Expenses and treat any over payment by Tenant like an overpayment of Rent
Adjustment Deposits, as set forth in subsection 3.F.2.c. If Landlord receives a
refund of Taxes or a reimbursement or refund of Expenses and if Tenant has paid
a Rent Adjustment based upon an Expense and/or Tax amount that includes the
amount being refunded or reimbursed, Landlord shall give Tenant a credit (or a
refund if such amount exceeds more than one month's Rent Adjustment) against
Tenant's Proportion of Expenses and Taxes for the Calculation Year in which such
refund or reimbursement is received or obtained (as the case may be) in the
amount of Tenant's Proportion of the refund or reimbursement.

FN 4.3. - continued from Section 4.A.1.

Landlord shall furnish heating and air-cooling with capacity to produce the
following results effective under normal business operation, daily from 7:00
A.M. to 6:00 P.M. (Saturdays 8:00 A.M. to 1:00 P.M.), Sundays and Holidays
excepted and within tolerances normal in first-class downtown Chicago highrise
office buildings:

        a. Heating capable of maintaining inside space conditions of not less
than 70(Degrees)F when the outside air temperature is not less than minus
5(Degrees)F dry bulb; and

        b. Air-cooling capable of maintaining inside space conditions of not
more than 79(Degrees)F dry bulb and at a 50% (plus or minus 5%) relative
humidity when the outside conditions are 95(Degrees)F dry bulb and 75(Degrees)F
wet bulb.

The foregoing is based upon occupancy density on each floor of the Premises of
not more than one (1) person for each one hundred twenty-five (125) square feet
of floor area on such floor and a maximum diversified electric lighting and
office machine load on each floor of the Premises of 5.5 watts per square foot
of floor area on such floor.

Notwithstanding the foregoing, Landlord shall not be liable to Tenant for any
failure to achieve or maintain the results set forth in Sections 4.A.1.a. or
4.A.1.b. above to the extent that such failure is caused by work performed by a
General Contractor (defined in the Work Supplement attached to this Lease as
Exhibit "C"), contractor or subcontractor retained by Tenant, materials and
equipment installed by such General Contractor, contractors or subcontractors,
Tenet's use of heat generating machines, equipment or lighting or an occupancy
density or electric lighting or office machine load on any floor of the Premises
in excess of the

                                      4(a)
<PAGE>

occupancy density and maximum diversified electric lighting and office machine
load set forth in the foregoing paragraph.

FN 4.4. - continued from Section 4.A.1.

If Tenant uses heat generating machines, equipment, lighting or has excessive
population density which affect the temperature otherwise maintained by the
air-cooling systems within the Premises only, Landlord shall not have the right
to install supplementary air-conditioning units in the Premises.

FN 4.5. - continued from Section 4.A.1.

(based upon the actual cost of the condenser water used in Landlord's cooling
tower for the use of tenants in the Building with supplemental units [the
"Supplemental Tower"], multiplied by a fraction, the numerator of which is the
rated capacity in tons of Tenant's supplemental unit(s), and the denominator of
which is the rated capacity in tons of the Supplemental Tower);

FN 4.6. - continued from Section 4.A.1.

(based upon the Landlord's cost of any labor, materials and supplies needed to
operate and maintain the Supplemental Tower plus fifteen percent (15%) overhead
and profit). The annual charge for 1987 for tenants in the Building with
supplemental units is $163.29 per ton. Upon written notice to Landlord, Tenant
may request heating or air-cooling during house other than those stated and
Landlord shall provide such additional heating and air-cooling at the sole
expense of Tenant which shall be based upon the cost of Landlord plus fifteen
percent (15%) overhead and profit;

FN 4.7. - continued from Section 4.A.2.

(such Base Building lavatories are those washroom facilities located in the core
of each floor of the Premises including all Base Building fixtures in such
washroom facilities, which are installed as of the date of this Lease and are
referred to in Exhibit "D" attached hereto). If Tenant does not occupy a full
floor of the Building, such usage shall be in common with other tenants on such
floor.

FN 4.8. - continued from Section 4.A.2.

or the M-1 space (defined in subsection 1.B. of the Support Space Supplement
attached to this Lease) for plumbing fixtures other than Base Building fixtures,

FN 4.9. - continued from Section 4.A.2.

(which shall be equal to the cost of such water to Landlord plus fifteen percent
(15%) overhead and profit),

FN 4.10. - continued from Section 4.A.3.

, provided that there shall be no charge to Tenant for freight elevator service
for its initial move-in to the Premises.

                                      4(b)
<PAGE>

          5. Window washing of all windows (inside and out) in the Premises, at
such times as shall be required in the sole judgment of Landlord FN 5.1.

        B. FN 5.2. All electricity used in the Premises shall be supplied by the
utility company serving the Building through a separate meter and be paid for by
Tenant. Landlord shall not in any way be liable or responsible to Tenant for any
loss, damage or expense which Tenant may sustain or incur if either the quantity
or character of electrical service is changed or is no longer available or
suitable for the requirements of Tenant. If such service be discontinued, such
discontinuance shall not in any way affect this Lease or the liability of Tenant
hereunder or cause a diminution of Base Rent or Rent Adjustment and the same
shall not be deemed to be a lessening or diminution of services within the
meaning of any law, rule or regulation now or hereafter enacted, promulgated or
issued. Tenant shall receive such service directly from the utility company and
Landlord hereby permits its wires and conduits, to the extent available,
suitable and safely capable, to be used for such purposes. Tenant shall not: 1.
make alterations or additions to the electrical equipment or appliances without
the consent of Landlord, or 2. use electrical current which exceeds the capacity
of the feeders, risers or wiring installation to the floor of the Premises or
the Premises FN 5.3. Tenant may at its option, purchase from Landlord or its
agent all lamps, bulbs, ballasts and starters used in the Premises after their
initial installation.

        C. Landlord does not warrant that any of the services or equipment used
in connection with the services stated in subsection A. and B. above will be
free from interruption caused by war, insurrection, civil commotion, riots, acts
of God or the enemy, governmental action, installation, wear, use, repairs,
renewal, improvements, alterations, strikes, lockouts, picketing, whether legal
or illegal, accidents, inability of Landlord to obtain fuel or supplies or any
other causes beyond the control of Landlord. Any such interruption of service
shall never be deemed an eviction or disturbance of the Use, render Landlord
liable to Tenant for damages, or relieve Tenant from performance of its
obligations under this Lease. FN 5.4.

        FN 5.5.

  5. Condition of Premises. FN 5.6. Tenant shall accept the Premises (including
improvements and personalty, if any) in its condition and "as-built"
configuration existing on the earlier of the date of Tenant takes possession or
the Commencement Date, and possession by Tenant shall be conclusive evidence
against Tenant that the Premises were in good order and satisfactory condition
when Tenant took possession. FN 5.7. No promise of Landlord to alter, remodel,
decorate, clean or improve the Premises or the Building and no representation
respecting the condition of the Premises or the Building have been made by
Landlord to Tenant, unless such are contained in this Lease.

  6. Commencement of Base rent and Rent Adjustments.

        A. Base Rent and Rent Adjustments shall commence (subject to subsection
C.) on the later to occur of:

               1.  the Commencement Date; and

               2. the date upon which the Base Building Work (as described in
Section I. Of the Work Supplement) in the Premises is substantially completed by
Landlord (even though minor insubstantial details of construction or mechanical
adjustment remain to be done).

        B.  Intentionally Omitted.

        C. If a holdover occurs in any space added to initial Premises
(described in Section 1 of this Lease), Base Rent and Rent Adjustments shall
commence upon vacation of such space by the holdover tenant. If Tenant occupies
the Premises and commences doing business in the Premises prior to the
Commencement date, Base Rent and Rent Adjustments shall commence on the day of
occupancy on a proportional per diem basis. FN 5.8.

FN 5.1. through 5.8. - see pages 5(a) - 5(b)

                                       5
<PAGE>

FN 5.1. continued from Section 4.A.5.

; provided, however, that the interior and exterior of the windows shall be
washed no less than three (3) times per year, weather permitting.

FN 5.2. - continued after Section 4.A.5.

6. Entrance reception service for the Building comparable to other first-class
downtown Chicago highrise office buildings.

FN 5.3. - continued from Section 4.B.

Landlord hereby grants Tenant unrestricted access to the telecommunications
closets and risers serving the Premises, provided that if Tenant requires access
to a telecommunications closet serving the Premises and located on a floor
occupied solely by a tenant other than Tenant, Tenant shall provide such tenant
and Landlord with advance notice of its intent to enter such telecommunication
closet and such entry shall be accessed by freight elevators only.

FN 5.4. - continued from Section 4.C.

In such circumstances, Landlord shall use reasonable efforts to promptly restore
service and, in the event any interruption in utility service causes the
Premises to be rendered untenantable (meaning that Tenant is unable to use such
space in the normal course of its business) by Tenant for the Use for more that
three (3) consecutive days after notice from Tenant to Landlord that such
service has been interrupted, Base Rent and Rent Adjustments shall abate on a
per diem basis for each day after such three (3) day period during which the
Premises remain untenantable.

FN 5.5. - continued after Section 4.C.

D. If (i) Landlord ceases to furnish any of the services referred to in this
Section 4 as a result of a condition which affects only the Building (and does
not affect office buildings in general in the Loop area of the City of Chicago),
(ii) such cessation is within the reasonable control of Landlord (that is, such
cessation is not caused by Force Majeure), (iii) such cessation does not arise
as a result of an act or omission of Tenant or any other person (excluding a
cessation which does arise as a result of an act or omission of any person other
than Tenant is such cessation is able to be cured by reasonable and prompt
action on the part of Landlord but has not been so cured), and (iv) as a result
of such cessation, the Premises, or any portion thereof is rendered untenantable
and Tenant in fact so ceases to use such space in the manner used prior to such
cessation, and (v) Landlord does not furnish such service within fifteen (15)
days after notice by Tenant stating the nature of the service which is being
furnished ("Service Interruption Notice"), then Tenant may, at the expense of
Landlord, perform the necessary repairs to restore the service that is the
subject of the Service Interruption Notice. All invoices received by Tenant for
the cost of such repair shall be submitted to Landlord for payment. If Landlord,
within the fifteen (15) day period referred to above, gives Tenant evidence
which is satisfactory, in the reasonable judgment of Tenant, that Landlord is
diligently pursuing a course which will restore the service

                                      5(a)
<PAGE>

which is the subject of the Service Interruption Notice and Landlord continues
to diligently pursue such course, Landlord shall be deemed to be furnishing such
service for purposes of this subsection 4.D. only.

FN 5.6. - continued from Section 5

Subject to (i) construction "punch list items" prepared on a floor by floor
basis which must be specified by Tenant in writing to Landlord within sixty (60)
days after the date of Tenant's occupancy of any floor of the Premises for the
purpose of performing Initial Alterations, and (ii) latent defects of which
Tenant notifies Landlord within ten (10) business days after discovery,

FN 5.7. - continued from Section 5

Landlord will diligently and continuously endeavor to complete the Base Building
Work. Notwithstanding the foregoing, if a s a result of Landlord's failure to
complete any item of Base Building Work, Tenant is prevented or delayed in
completing the Initial Alterations, Tenant shall so notify Landlord. If Landlord
does not complete such item of Base Building Work within five (5) business days
after such notice (plus such additional time as may be necessary to complete
such Base Building Work with diligent continuous effort), Tenant may cause such
Base Building Work to be completed by Tenant's contractors at the Landlord's
expense, which costs Landlord shall promptly pay upon receipt of invoices from
Tenant or its contractors. Any such Base Building Work performed by Tenant's
contractors shall be performed in a good and workmenlike manner in accordance
with the plans for the Building and Base Building standards. Any defects in such
work shall be repaired by Tenant or its contractor at Tenant's expense.

FN 5.8. - continued from Section 6.C

, it being understood that the Expense/Tax Cap, as set forth in Section 3.D,
shall not commence until the Commencement Date and the Installment Credits shall
not commence until April, 1998, as set forth in Section 27.

                                      5(b)
<PAGE>

        D.  FN 6.1.

   7. Use of Premises. Tenant shall occupy and use the Premises during the Term
for the Use and no other purpose:

        A. Tenant will not make or permit to be made any use of the Premises
which, directly or indirectly, is forbidden by public law, ordinance or
governmental regulation or which may be dangerous to persons or property, or
which may invalidate or increase the premium cost of any policy of insurance
carried on the Building or covering its operations and Tenant shall not do, or
permit to be done, anything upon the Premises which will be in conflict with
fire insurance policies covering the Building.  Tenant, at its sole expense
shall comply with all rules, regulations or requirements of the Fire Department,
applicable fire insurance inspection or rating bureau, or any other similar
body, and shall not do, or permit anything to be done upon the Premises, or
bring or keep anything thereon in violation of rules, regulations or
requirements of the Fire Department, or applicable fire insurance inspection or
rating bureau, or other authority having jurisdiction and then only in such
quantity and manner of storage as not to increase the rate of fire insurance
applicable to the Building;

        B.  FN 6.2.

        C. Intentionally Omitted.

        D. Tenant shall not obstruct, or use for storage, or for any purpose
other than ingress and egress, the sidewalks, entrances, passages, courts,
corridors, (outside of the Premises), vestibules, halls, elevators or stairways
FN 6.3. of the Building;

        E. no bicycle or other vehicle and no dog or other animal or bird shall
be brought or permitted to be in the Building or on the Premises;

        F. FN 6.4. Tenant shall not: 1. create or maintain a nuisance on the
Premises, or 2. disturb, solicit or canvass any occupant of the Building;

        G. Tenant shall not install any musical instrument or equipment in the
Premises or the Building, or any antennas, aerial wires or other equipment
inside or outside the Building, without obtaining the approval of Landlord. The
use thereof, if permitted, shall be subject to control by Landlord to the end
that others shall not be disturbed or annoyed;

        H. Tenant shall not waste water by tying, wedging or otherwise fastening
open any faucet;

        I. except as provided in Section 34, no additional locks or similar
devices shall be attached to any door. No keys for any door other than those
provided by Landlord shall be made. If more than two keys for one lock are
desired by Tenant, Landlord may provide the same upon payment by Tenant. Upon
termination of this Lease or of the possession of Tenant, Tenant shall surrender
all keys to the Premises and shall make known to Landlord the explanation of all
combination locks on safes, cabinets and vaults:

FN 6.1. through FN 6.4. - see page 6(a)

                                       6
<PAGE>

FN 6.1. - continued from Section 6.D.

Landlord shall not incur any liability if (i) Base Building Work (defined in
Exhibit "C" attached hereto) is not completed in the Building on the
Commencement Date or if (ii) the premises are not ready for occupancy on the
Commencement Date, and the fact that Base Building Work in the Building is not
completed on the Commencement Date or that the Premises are not ready for
occupancy on the Commencement Date shall not affect the validity of this Lease
or the obligations of Tenant hereunder, nor shall the same be construed to delay
the Commencement Date or Tenant's obligation to pay Base Rent (subject to
Section 27) and Rent Adjustments (subject to Section 3.D.), or to extend the
Expiration Date or the Term; provided, however, if Landlord fails to make the
Premises available to Tenant and its General Contractor for construction of the
Initial Alterations immediately upon execution of this Lease (as required by
Section II.A.1. of the Work Supplement attached hereto as Exhibit "C") and such
delay causes Tenant and its General Contractor to be unable to make the Premises
ready for occupancy on the date the Premises would have been ready for occupancy
absent of such delay, then Base Rent and Rent Adjustments shall abate for a
period of time equal to the number of days in the Delay Period. For purposes of
this Section 6.D., the term "Delay Period" means the period of time commencing
upon the day after the execution of this Lease and ending on the date Landlord
makes the Premises available to Tenant and its General Contractor for
construction of the Initial Alterations, plus any period thereafter that the
Landlord, without cause, revokes or withholds the License or the availability of
the Premises to Tenant and its General Contractor. The delivery by Landlord to
Tenant of a fully executed copy of this Lease shall constitute permission for
Tenant and its General Contractor to enter into the Premises for construction of
Initial Alterations. No further documentation or notice shall be required from
Landlord to Evidence such permission.

FN 6.2. - continued from Section 7.B.

any sign installed in the Premises shall be installed at the expense of Tenant.
Landlord may grant or withhold its approval in its sole discretion if such sign
is visible from the exterior of the Building. Landlord may grant or withhold its
approval in its reasonable discretion if such sign is located on a floor on
which Tenant is not the sole tenant and is visible from the exterior of the
Premises.

FN 6.3. - continued from Section 7.D.

and Tenant shall not obstruct, or use for storage, or for any purpose other than
ingress and egress, the corridors or stairways located within the Premises if
such obstruction or use would violate Section 7.A. above.

FN 6.4. - continued from Section 7.F.

Tenant shall not cause or permit any noise, odor or litter, which is materially
disruptive of the use or enjoyment of (i) the premises of another tenant or (ii)
the common areas of the Building by Landlord or other occupants of the Building,
to emanate from the Premises. Tenant shall use reasonable efforts to ensure that
its customers, clients, invitees and guests do not violate the prohibition set
forth in the immediately preceding sentence.

                                      6(a)
<PAGE>

        J. Tenet accepts full responsibility for: 1. protecting the Premises
from theft, robbery and pilferage, 2. keeping the Premises secure, and 3.
locking the doors in and to the Premises , Any damage resulting from neglect of
this subsection shall be paid for by Tenant. All property belonging to Tenant,
or any person in the Premises, which is in the Building or the Premises, shall
be there at the risk of Tenant or other person only, and subject to Section
15.D. Landlord, its beneficiaries, Owner and the partners of Owner and their
respective agents and employees shall not be liable for damages thereto or theft
of misappropriation thereof. Subject to Section 15.D. Tenant shall indemnify and
hold Landlord, its beneficiaries. Owner and the partners of Owner and their
respective agents and employees harmless from any claims arising out of the
above, including subrogation claims by the insurance carrier of Tenant;

        K. if Tenant desires telegraphic, telephonic, burglar alarm or signal
service, Landlord will, upon request, direct where and how connections and all
wiring for such service shall be introduced and run. Without such directions, no
boring, cutting or installation of wires or cables I permitted. FN 7.1.

        L. shades, draperies or other form of inside window covering must be of
such shape, color and material as approved by Landlord. The decision of Landlord
to refuse such approval shall be conclusive;

        M. Tenant shall not overload any floor. Safes, furniture and all large
articles shall be brought through the Building and into the Premises at such
times and in such manner as Landlord shall permit and at the sole risk and
responsibility of Tenant. Tenant shall issue passes listing all furniture,
equipment and similar articles to be removed from the Building, before Building
employees will permit any article to be removed FN 7.2.

        N. unless Landlord gives consent, Tenant shall not install or operate
any steam or internal combustion engine, boiler, machinery, refrigeration or
heating device or air-conditioning apparatus in or about the Premises, or carry
on any mechanical business therein, or use the Premises for housing
accommodations or lodging or sleeping purposes, or do any cooking therein or
install or permit the installation of any vending machines, or use any
illumination other than electric light, or use or permit to be brought into the
Building any flammable oils or fluids such as gasoline, kerosene, naphtha and
benzene, or any explosive or other articles hazardous to persons or property.
Should Landlord grant consent, the installation, operation and maintenance
expenses of Tenet for any such items shall include, among other charges as
additional Base Rent at rates fixed by Landlord, if air-conditioning apparatus
is being installed, charges for a condenser water riser tap-in fee and condenser
water based upon the rated capacity in tons of the unit FN 7.3.

        O. FN 7.4. Tenant shall not place or allow anything to be against or
near the glass or partitions or doors of the Premises which may diminish the
light in, or be unsightly from, public halls or corridors;

        P. Tenant shall not install any equipment in the Premise which uses a
substantial amount of electricity without the consent of the Landlord. FN 7.5.
The consent of Landlord to the installation of electric equipment shall not
relieve Tenant from the obligation not to use more electricity that such safe
capacity;

        Q. Tenant may not install carpet, padding, or carpet by means of a
mastic, glue or cement without the consent of Landlord;

        R. Tenant shall not conduct any auction, fire or "going out of
business", or bankruptcy sales in or from the Premises;

        S.  Tenant shall not lower and adjust the venetian blinds on the windows
in the Premises is such lowering and adjusting reduces the sun load;

        T. in addition to all other liabilities for breach of any covenant of
this section 7, Tenant shall pay to Landlord all damages caused by such breach
and shall also pay to Landlord as additional Base Rent an amount equal to any
increase in insurance premium or premiums caused by such breach. Any violation
of this section 7 may

FN 7.1. through FN 7.5. - see page 7(a)

                                       7
<PAGE>

FN 7.1. - continued from section 7.K.

Tenant may, at its expense, furnish to its Members, communications services from
a centralized switch, or a group of switches. Said communication services may be
directly wired from the switch location to Members' premises via vertical and/or
horizontal raceways (a means for wire and/or cable to be distributed from one
point to another). The location of the switch (or switches) and the routing and
location of the raceways shall be approved by Landlord. Landlord and Tenant
shall cooperate with each other so that the integrity of the System (Section
9.A.) of the Building is not disturbed;

FN 7.2. - continued from Section 7.M.

, provided that Landlord shall not be responsible for determining the
authenticity of such passes;

FN 7.3. - continued from Section 7.N.

, which charges shall be at the rates set forth in Section 4.A.1. Tenant is
granted permission to install a kitchen which may include a refrigerator,
vending machines and microwave ovens for use by employees and invitees of Tenant
only. Such installation shall: 1. include: a. required ducts, vents and/or
flues, b. an exhaust stack tap-in charge based upon the proportionate C.F.M.
usage of Tenant, and c. a water meter, if Landlord in its sole judgment
determines such is warranted, and 2. be at the sole expense of Tenant, provided,
however, that if such kitchen is part of the Initial Alterations (as defined in
Section II.A. of the Work Supplement attached hereto as Exhibit "C"), Tenant
may, at its discretion, apply a portion of its Work Credit (defined in Section
27.B. of this Lease) against the cost of such installation in accordance with
Section 27;

FN 7.4. - continued from Section 7.0.

on multi-tenant floors or the Lobby Space (defined in the Support Space
Supplement to this Lease),

FN 7.5. - continued from Section 7.P.

Landlord represents that the maximum diversified electrical capacity available
for utilization is 5.5 watts per rentable square foot of floor area on each
floor within the Premises. If additional capacity in the Premises is required
and possible to provide, in Landlord's judgment taking into account the capacity
of the electric wiring in the Building and the Premises and the needs of other
tenants in the Building, it shall be provided at the sole expense of Tenant.
Nothing in this Section 7.P. shall affect in any way Tenants obligation to pay
for all Alterations (including without limitation, all Alterations to electrical
system in the Premises) and otherwise comply with Section 9 with respect to all
Alterations.

                                      7(a)
<PAGE>

be restrained by injunction. Tenant shall be liable to Landlord for all damages
resulting from violation of any of the provisions of this Section 7. Landlord
shall have the right to make such reasonable rules and regulations as Landlord
or its agent may from time to time adopt on such reasonable notice to be given
as Landlord may elect. FN 8.1. Nothing in this Lease shall be construed to
impose upon Landlord any duty or obligation to enforce provisions of this
Section 7 or any rules and regulations hereafter adopted, or the terms,
covenants or conditions of any other lease as against any other tenant, and
Landlord shall not be liable to Tenant for violation of the same by any other
tenant, its servants, employees, agents, visitors or licensees.

        8. Care and Maintenance. Subject to the provisions of Sections 4.A.4,
11,13 and 33. Tenant, at its sole expense, shall keep the Premises FN 8.2. in
good order, condition and repair during the Term, FN 8.3. If Tenant does not
make repairs promptly and adequately, Landlord may, but need not, make repairs
and Tenants shall promptly pay the expense thereof. Tenant shall pay Landlord
for overtime and for any other expenses incurred if repairs, alterations,
decorating or other work in the Premises, at the request of Tenant, are not made
during ordinary business hours.

        9. Alterations and Construction.

             A. FN 8.4. such as, but not limited to, painting, decorating,
erecting partitions, making alterations or additions, nailing, boring or
screwing into the ceilings, walls or floors without the consent of the Landlord
FN 8.5. For each Alteration, Tenant shall furnish Landlord: 1. plans and
specifications for the Alterations (which Tenant warrants are in conformance
with all applicable laws and consistent in all respects with the aesthetics and
the following "Systems" of the Building: electrical, heating, ventilating,
air-cooling, plumbing/fire protection and structural) prepared at the expense of
Tenant, by the Building engineers, or at the discretion of Landlord, other
engineers acceptable to Landlord, 2. affidavits from such engineers stating that
the Alterations will not in any way adversely affect any Systems in the
Building, 3. names and address of contractors ("Contractors") and subcontractors
("Subcontractors"), 4. copies of contracts with Contractors and Subcontractors
which shall provide, among other things, that no changes, amendments, extras or
additional work FN 8.6. are permitted without the consent of Landlord FN 8.7.
Landlord reserves the right to deny any Contractor or Subcontractor entry to the
Building but the failure of Landlord to exercise this right shall not be deemed
an approval of either the financial stability or quality of workmanship of any
such Contractor or Subcontractor.

        B. If Landlord grants such consent or if Landlord consent is not needed
pursuant to the guidelines set forth in Section 9.A., all Alterations shall be
performed at the sole expense of Tenant, in a workmanlike manner and materials
furnished shall be of a like quality to those in the Building. If the
Alterations involve any Systems, such shall be performed under the supervision
of Landlord and by contractors approved by Landlord. If the Alterations do not
involve Systems, such shall be performed under the supervision of Landlord.
Regardless of whether Landlord's consent is required, before the commencement of
the Alterations or delivery of any materials onto the Premises or into the
Building. Tenant shall furnish Landlord: FN 8.8. 1. sworn Contractor affidavits
listing all subcontractors with suppliers of materials and/or labor, with whom
Contractors have contractual relations for the Alterations, and setting forth a
summary of such contractual relationships. 2. Subcontractor affidavits, 3.
certificates of insurance from all Contractors and Subcontractors performing
labor or furnishing materials, insuring against any and all claims, costs,
damages, liabilities and expenses which may arise in connection with the
Alterations, and 4. such other documents as may be reasonably requested by
Landlord. The certificates of insurance required must evidence coverage in
amounts and from companies satisfactory to Landlord and may be cancelable only
with ten (10) days advance notice to Landlord. If Landlord consents or
supervises, such shall not be deemed a warranty as to the adequacy of the design
or workmanship or quality of the materials and Landlord hereby disavows any
responsibility and/or liability for such. Additionally, under no circumstances
shall Landlord have any responsibility to repair or maintain any portion of the
Alterations which either does not function or ceases to function.

FN 8.1. through FN 8.8. - see pages 8(a) through 8(b)

                                       8
<PAGE>

FN 8.1. - continued from Section 7.T.

Landlord will make reasonable efforts to enforce all such rules and regulations
uniformly. In the event of a conflict between such rules and regulations and
this Lease, this Lease shall control.

FN 8.2. - continued from Section 8

(excluding the Systems [Section 9.A.], structural elements of the Building and
glass of the Building which Landlord agrees to maintain pursuant to Section 33).

FN 8.3. - continued from Section 8

ordinary wear and tear and damage by fire or other casualty excepted, and Tenant
shall have no obligation to repair any damage caused by negligence of Landlord,
its agents, servants or employees, which damage shall be repaired by Landlord,
at its expense.

FN 8.4. - continued from Section 9.A.

Tenant may do work ("Alterations", such defined term shall collectively refer to
the Initial Alterations [defined in the Work Supplement attached hereto as
Exhibit "C"] and any subsequent Alterations) in the Premises,

FN 8.5. - continued from Section 9.A.

If the Alterations:

        (i) are of a cosmetic nature such as painting, wallpapering, hanging
pictures, millwork and carpeting (Alterations of a cosmetic nature are called
"Cosmetic Alterations"), and are not visible from the exterior of the Premises
or the Building, or

        (ii) do not affect the Building Systems or structure, and are not
visible from the exterior of the Premises or the Building,

provided that even if Landlord's consent to an Alteration is not required,
Tenant shall still comply with this section 9, except that Tenant need not
comply with Sections 9.A.1., 9.A.2. and 9.B.1.  (only) to perform the following
Cosmetic  Alterations:  painting, wallpapering, hanging pictures, millwork and
carpeting.

        If the Alterations:

        (iii) affect the Building Systems or structure, or

        (iv) are visible from the exterior of the Premises or the Building;

the consent of the Landlord is required. Such consent shall not be unreasonably
withheld if the Alterations affect the Building Systems or structure or are
visible only from the exterior of the Premises and are not visible from the
exterior of the Building; if, however, the Alterations affect the Building
Systems or structure of the

                                      8(a)
<PAGE>

Building or are Cosmetic Alterations and in addition, such Alterations are
visible from the exterior of the Building, the consent of the Landlord shall be
within its sole and absolute discretion and the decision of Landlord to refuse
such consent shall be conclusive.

FN 8.6. -  continued from Section 9.A.

that is material or would affect the Building Systems or structure or result in
a change that would be visible from the exterior of the Premises or the Building

FN 8.7. - continued from Section 9.A.

, and Tenant agrees that it will not make or authorize any such changes,
amendments, extras or additional work without Landlord's consent. Tenant shall
provide Landlord with written notice of all changes, amendments, extras or
additional work that do not require Landlord's consent as soon as practical but
not more than five (5) business days after Tenant is aware that such change,
amendment, extras or additional work will be included in an Alteration. Tenant's
notice shall contain a description of the change, amendment, extras or
additional work and cost thereof.

FN 8.8. - continued from Section 9.B.

1. necessary permits; provided, however, if Tenant or its Contractor for an
Alteration cannot promptly obtain a building permit from the City of Chicago to
perform such Alteration in the Premises (including, without limitation, any of
the Initial Alterations) Tenant may, at its option, commence construction of
such Alteration and obtain delivery of materials therefore prior to obtaining
the building permit if Tenant delivers to Landlord, prior to commencement of
construction or delivery of materials, a "blue card" or substitute therefore
issued by the City of Chicago as evidence of receipt of Tenant's plans for the
Alteration and any other documentation customarily required by owners of
first-class highrise office buildings in downtown Chicago prior to allowing a
tenant to perform such alteration in its premises. Tenant shall, in any event,
deliver permit to Landlord after it is obtained. In the event that Tenant
commences construction of an Alteration or obtains delivery of materials
therefore prior to obtaining a building permit, pursuant to this Section 9.B.1.,
Tenant hereby agrees to indemnify and save all of the Landlord related Parties
harmless against any and all claims, demands, liabilities, costs and expenses
(including, without limitation, reasonable attorney's fees for the defense
thereof) arising from or connected in any way with (i) the commencement or
completion of construction of an Alteration or the delivery of materials
therefore to the Premises or Building prior to the obtaining of a building
permit with respect to such Alteration, or (ii) Landlord granting permission to
Tenant, pursuant to this Section 9.B.1., to commence construction of an
Alteration and obtain delivery of materials prior to Tenant obtaining a building
permit.

                                      8(b)
<PAGE>

        C.  Intentionally Omitted.

        D. Upon completion of the Alterations, and prior to final payment.
Tenant shall obtain the written approval of Landlord for the quality of the
Alterations and furnish Landlord with: 1. Tenant, Contractors, and architectural
completion affidavits. 2. full and final waivers of lien, 3. receipted bills
covering all labor and materials expended and used. 4. other appropriate
documents evidencing completion of the Alterations and 5. as-built plans of the
Alterations.

        E.  FN 9.1.

        F. Intentionally Omitted.

        G. Tenant shall procure, or cause to be procured, and pay for all
permits, licenses, approvals, certificates and authorizations necessary to the
prosecution and completion of the Alterations. All Alterations shall be done in
strict accordance with all laws, ordinances, rules, regulations and requirements
of any applicable board of underwriters or fire rating bureau and all municipal,
state, federal and other authorities having jurisdiction. Where drawings and
specifications conflict with the law, the law is to be followed. Tenant shall
promptly notify the respective departments or official bodies when the
Alterations are ready for inspection and shall, at once, do all work required to
remove any violations or to comply with such inspections, without additional
charge to Landlord. Tenant shall perform, or cause to be performed, all work
necessary to obtain approvals from authorities mentioned above without
additional cost to Landlord.

        H. Tenant agrees to reimburse Landlord for all sums expended for
examination and approval of the architectural and mechanical plans and
specifications.

        I. Tenant agrees that Alterations shall be performed so as not to cause
or create any jurisdictional or other labor disputes, and in the event such
disputes occur, Tenant shall immediately do whatever is necessary to resolve
such disputes, at no expense to Landlord.

        J. FN 9.2. Tenant hereby agrees to indemnify and hold Landlord, its
beneficiaries. Owner and partners of Owner and their respective agents and
employees harmless from any and all liabilities of every kind and description,
including reasonable attorney's fees which may arise out of or be connected in
any way with the Alterations. Any mechanic's lien (or any notice preliminary to
lien) filed against the Premises, or the Real Property, for the Alterations or
materials claimed to have been furnished to Tenant shall either 1. be discharged
of record (or paid if a notice be served) by Tenant within ten (10) days after
filing (or service) at the expense of Tenant, FN 9.3.

        K. All additions, decorations, FN 9.4. hardware, non-trade fixtures and
all improvements, in or upon the Premises FN 9.4. whether placed there by Tenant
or Landlord, shall , unless Landlord requests their removal as provided below,
become the property of Landlord and shall remain upon the Premise at the
termination of this Lease by lapse of time or otherwise without compensation,
allowance or credit to Tenant. If, upon the request of Landlord, Tenant does not
remove said additions, decorations, fixtures, hardware, non-trade fixtures and
improvements, Landlord may remove them FN 9.5.

        10. Access to Premises. Tenant shall permit Landlord to erect, use and
maintain pipes, ducts, wiring and conduits in and through the Premises FN 9.6.
Landlord or agents of Landlord shall have the right to enter upon the Premises,
to inspect the same, to perform janitorial and cleaning services and to make
such repairs,

FN 9.1. through FN 9.6. - see page 9(a) - 9(b)

                                       9
<PAGE>

FN 9.1. - continued from Section 9.E.

E. Tenant shall reimburse Landlord for use of elevators and/or hoists during the
Alterations for only the actual costs incurred by Landlord in providing for such
use. Landlord and Tenant shall cooperate with each other in scheduling such use
and whenever possible during normal business hours (or non-business hours, if
required) in the course of the Alterations.

FN 9.9. - continued from Section 9.J.

Except for Alterations performed by Metropolitan Structures Construction
Division, as General Contractor,

FN 9.3. - continued from Section 9.J.

or 2. contested by Tenant, so long as (i) Tenant , at Tenant's expense, obtains
title insurance insuring over the notice of lien or the lien from Chicago Title
and Trust Company, or another local, reputable title company acceptable to
Landlord and Tenant, in favor of Landlord and any mortgagee or ground lessor
with an interest in the Building, or provides Landlord with alternative security
satisfactory to Landlord insuring over any possible loss or expense which may
arise from non-discharge of such lien; provided that Tenant shall not be
required to provide such title insurance or alternative security, unless the
filing of a mechanics lien (or any notice preliminary to the lien) is considered
an event of default under the terms of any loan secured by the Building existing
as of the date of such filing or at some time during the period beginning when
such lien is filed (or notice is delivered) and ending upon discharge or payment
thereof, Landlord is making (or is entitled to make) draws on a loan secured by
the Building, or is otherwise required by the terms of any financial documents
to provide such title insurance or alternative security, or is or commences the
refinancing of a loan secured by the Building or is in the process of or
commences the process of selling, transferring, pledging or hypothecating the
beneficial interest in Landlord, the Real Property, the Building or any interest
in any thereof (provided further, that if the granting of this right in any way
damages Landlord, Tenant shall immediately provide title insurance or
alternative security and indemnify Landlord), and (ii) such contest is in good
faith and by appropriate proceedings which operate to stay the enforcement of
such mechanic's lien. Tenant shall, promptly after the final determination of
such contest, pay or discharge any decision or judgment rendered, together with
all costs, charges, interest and penalties incurred or imposed or assessed in
connection with such contest.

FN 9.4. - continued from Section 9.K.

(other than personal property),

FN 9.5. - continued from Section 9.K.

; provided, however, that Landlord shall notify Tenant on or before the time it
grants approval as to any plans and specifications submitted by Tenant for an
Alteration as to whether Landlord will require that Tenant remove, at the
termination of this Lease, such Alteration or any particular portion thereof.

                                      9(a)
<PAGE>

Notwithstanding the foregoing, Landlord shall have to the right to require
Tenant to remove any vault or stairway installed in the Premises, regardless of
whether Landlord timely notified Tenant that it would require removal. Landlord
shall not have the right to retain any of Tenant's personal property or
equipment (including computers and supplemental air conditioning units).

FN 9.6. - continued from Section 10

Provided, however, that such pipes, ducts, wiring and conduits (and the
installation thereof in and through the Premises): a) are concealed; and b) may
not diminish or alter the configuration of the Premises (unless required by law)
without the consent of Tenant, which shall not be unreasonable withheld or
delayed; and c) shall not interfere with installations previously made by Tenant
or the Use.

                                      9(b)
<PAGE>

alterations, improvements or additions to the Premises or the Building as
Landlord may deem necessary and Landlord be allowed to take all materials into
and upon the Premises that may be required therefore without the same
constituting an eviction of Tenant in whole or in part and the Base Rent and/or
Rent Adjustments shall in no way abate (except as provided in Section 11) while
said repairs, alterations, improvements, or additions are being made, by reason
of loss or interruption of business of Tenant, or otherwise FN 10.1. If Tenant
shall not be personally present to open and permit an entry into the Premises,
at any time, when for any reason an entry therein shall be necessary or
permissible, Landlord or agents of Landlord may enter the same by a master key,
or may forcibly enter the same, without rendering Landlord or such agents liable
therefore (if during such entry Landlord or agents of Landlord shall accord
reasonable care to the property of Tenant) and without in any manner affecting
the obligations and covenants of this Lease. Nothing herein contained, however,
shall be deemed or construed to impose upon Landlord any obligations,
responsibility or liability whatsoever, for the care, supervision or repair of
the Building or any part thereof, other than as herein provided. Landlord shall
also have the right at any time, without the same constituting an actual or
constructive eviction and without incurring any liability to Tenant therefore,
to construct and lease kiosks on any part of the building, other than the
Premises (including, but not limited to, exterior and interior public areas), to
change the arrangement and/or location of entrances or passageways, doors and
doorways, and corridors, elevators, stairs, toilets or other public parts of the
Building, and to close entrances, doors, corridors, elevators and other
facilities FN 10.2. Except as provided in Section 15.D., Landlord shall not be
liable to Tenant for any expense, injury, loss or damage resulting from work
done in or upon, or the use of, any adjacent or nearby building, land, street or
alley.

        11.    Untenantability.

               A. If the Premises or the Building are untenantable by fire or
other casualty, FN 10.3. Landlord may elect to:

                      1. terminate this Lease as of the date of the fire or
casualty by notice to Tenant within one hundred twenty (120) days after date, or

                      2. proceed with reasonable diligence to repair, restore or
rehabilitate the Building or the Premises at the expense of Landlord, in which
latter event this Lease shall not terminate FN 10.4.

               B. In the event this Lease is not terminated pursuant to this
section, Base Rent and Rent Adjustments shall abate on a per diem basis during
the period of untenantability FN 10.5. IN the event of the termination of this
Lease pursuant to this section, Base Rent and Rent Adjustments shall be
apportioned on a per diem basis and paid to the date of the fire or other
casualty* In the event the Premises are partially damaged by fire or other
casualty but not made wholly untenantable, then Landlord shall, except during
the last year of the Term proceed with reasonable diligence to repair and
restore the Premises and Base Rent and Rent Adjustments shall abate in
proportion to the FN 10.6. dunning the period of untenantability. If a portion
of the premises are made untenantable as aforesaid during the last year of the
Term as it may be extended from time to time. Landlord or Tenant shall have the
right to terminate this Lease as of the date of the fire or other casualty by
giving notice thereof to the other within thirty (30) days after the date of the
fire or other casualty, in which event Base Rent and Rent Adjustments shall be
apportioned on a per diem basis and paid to the date of such fire or other
casualty*.

        12.    Insurance.

               A. Landlord and Tenant agree to have any and all fire, extended
coverage or any and all material damage insurance which may be carried endorsed
with the following subrogation clause: "This insurance shall not be invalidated
should the insured waive in writing prior to a loss any or all right to recovery
against any party for loss occurring to the property described herein"; and
Landlord and Tenant hereby waive all claims for recovery from the other for the
loss or damage to any of its property insured under valid and collectible

FN 10.1. through FN 10.6. - see pages 10(a) - 10 (b)

* with respect to any portion of the Premises that is rendered untenantable and
to the date of the termination of this Lease with respect to the portion that is
not rendered untenantable and which Tenant continues to occupy after the date of
such fire or casualty.

                                       10
<PAGE>

FN 10.1. - continued from Section 10

; provided, however, that excepting emergency situations as determined by
Landlord, Landlord shall exercise reasonable efforts:

        1)     not to interfere with the conduct of the business of Tenant on
        the Premises;

        2)     to effect such entry during non-business hours; and

        3)     to give Tenant advance notice of any entry, provided that such
        notice by Landlord may verbal (rather  than  written) if in the judgment
        of Landlord, such verbal notice is sufficient;

and provided further, that Landlord shall not use the Premises as a storage area
for equipment and supplies for work being performed by Landlord in the Building
or in the Premises.

Notwithstanding anything contained in this Section 10 to the contrary, in the
event access by Landlord into the Premises pursuant to this Section 10 renders
the Premises or a portion thereof untenantable by Tenant for the Use (excepting
untenantability resulting from fire or other casualty) for more than five (5)
consecutive business days after notice from Tenant to Landlord that Landlord's
access has rendered the Premises or a portion thereof untenantable, then Base
Rent and Rent Adjustments shall abate on a per diem basis for each day after
such five (5) day period that the Premises or such portion remain untenantable,
provided that the abatement shall be in proportion to the portion of the
Premises which is rendered untenantable.

FN 10.2. - continued from Section 10

so long as the same does not materially alter or diminish Tenant's access to the
Premises.

FN 10.3. - continued from Section 11.A.

and if no portion of the Trading Floors has been made untenantable or if all or
a portion of the Trading Floors has been made untenantable, if the owner of the
Trading Floors provides Landlord with notice within ninety (90) days after the
Trading Floors have been made untenantable of its commitment to repair, restore
or rehabilitate the Trading Floors, then this Lease shall not terminate.
Landlord, at its expense, shall proceed with all due diligence to repair,
restore or rehabilitate all damaged portions of the exterior of the Building to
the extent necessary to restore the Premises, all other areas of the Building
serving the Premises or providing ingress to or egress therefrom (including,
without limitation, the parking garage, Building lobbies and all areas occupied
by equipment or other facilities serving the Premises or the Trading Floors).
If, however, the Premises or the Building and a portion of the Trading Floors
are made untenantable by fire or other casualty and if the owner of the Trading
Floors does not so notify Landlord within such ninety (90) day period of its
commitment to repair, restore or rehabilitate the Trading Floors,

                                     10(a)
<PAGE>

FN 10.4. - continued from Section 11.A.2.

; provided, however, if Landlord fails to repair, restore or rehabilitate the
Premises within two hundred seventy (270) days after the aforementioned one
hundred twenty (120) days, then Tenant shall have the right to terminate this
Lease as of the date of the fire or casualty by serving notice on Landlord
within ten (10) days after the expiration of the said two hundred seventy (270)
day period, provided further, however, that if Landlord fails to so repair,
restore or rehabilitate within said two hundred seventy (270) day period and
such failure is the result of delays caused by Force Majeure or Acts of Tenant,
the two hundred seventy (270) day period shall be deemed extended for a period
of time equal to the total of all such delays.

FN 10.5. - continued from Section 11.B.

, except in cases of fire or other casualty caused by the negligence of Tenant
or a Tenant Related Party (defined in Section 15.E.2.) to the extent that
Landlord's rent loss insurance does not cover such Base Rent or Rent
Adjustments; provided, however, that id Landlord maintains rent loss insurance
coverage in an amount less than that customarily carried by prudent owners of
similar first-class highrise office buildings in the downtown Chicago area (the
amount customarily carried from time to time shall be called "Customary Rent
Loss Coverage") then for purposes of determining pursuant to this Section 11.B.
whether Landlord's rent loss insurance covers Tenant's Base Rent and Rent
Adjustments, Landlord shall be deemed to maintain Customary Rent Loss Coverage,
and provided further, that if Landlord does not complete restoration and repair
work within the time period during which Landlord's rent loss insurance covers
Tenant's Base Rent and Rent Adjustments (the "Rent Loss Coverage Period") by
reason of Landlord's failure to perform such restoration and repair with
reasonable diligence (as opposed to by reason of Force Majeure or Acts of
Tenant) (provided that reasonable diligence shall not require that Landlord or
its contractors work overtime hours), then for purposes of determining pursuant
to this Section 11.B. whether Landlord's rent loss insurance covers Tenant's
Base Rent and Rent Adjustments, the Rent Loss Coverage Period shall be deemed to
be extended by a period equal to the number of days from the date of expiration
of the Rent Loss Coverage Period to the date of completion of the restoration
and repair, less the number of days that Landlord was delayed in completing
repair and restoration by reason of Force Majeure or Acts of tenant.

FN 10.6. - continued from Section 11.B.

area of the Premises that is untenantable and/or not reasonably usable by Tenant
by reason of damage to the balance of the Premises

                                     10(b)
<PAGE>

insurance policies to the extent of any recovery collected under such insurance
FN 11.1.

        B. 1. During the Term, Tenant, at its sole expense, shall obtain and
keep in force the following insurance: Comprehensive general liability written
on an "occurrence" or "claims made" basis, including personal and bodily injury,
broad form property damage, owner's protective coverage and contractual
liability, limits not less than $1,000,000.00 FN 11.2. and

              2.  all such insurance policies shall;

               a. name Tenant as named insured and name Landlord and the
               mortgages of the Building (and, if applicable, ground or primary
               lessors) as additional insureds as their respective interests may
               appear; and

               b. be insured by insurers and in form satisfactory to Landlord.

             3. Tenant shall deliver certificates of insurance or certified
copies of each policy to Landlord on or before ten (10) days prior to the date
Tenant takes possession of any part of the Premises.

             4. All policies shall contain an undertaking by the insurers to
notify Landlord and the mortgages of Landlord (and, if applicable, ground or
primary lessors) in writing, by Registered or Certified U.S. Mail, return
receipt requested, not less than fifteen (15) days before any material change,
reduction in coverage, cancellation or termination.

     13.       Eminent Domain.

           A. In the event the entire Building, Real Property or Premises shall
be lawfully condemned or taken in any manner for any public or quasi-public use,
this Lease and the Term and estate hereby granted shall forthwith cease and
terminate as of the date of the taking of possession by the condemning
authority. In the event that only a part of the Premises shall be so condemned
or taken then, effective as of the date of the taking of possession by the
condemning authority. Base Rent and Rent Adjustments shall abate in an amount
apportioned according to the area of the Premises so condemned or taken. If only
part of the Building or Real Property shall be so condemned or taken FN 11.3.
then 1. Landlord (whether or not a material portion of the Premises be affected)
may, at the option of Landlord, terminate this Lease and the Term and estate
hereby granted as of the date of such taking of possession by the condemning
authority by notifying Tenant of such Termination within sixty (60) days
following the date on which Landlord shall have received notice of the taking of
possession by the condemning authority, or 2. if such condemnation or taking
shall be of a material (more than twenty (20%) of the Rentable Area part of the
Premises or of a substantial part of the means of access of access thereto,
Tenant may, at the option of Tenant, by delivery of notice to Landlord within
sixty (60) days following the date on which Tenant shall have received notice of
the taking of possession by the condemning authority, terminate this Lease and
the Term and estate hereby granted as of the date of the taking of possession by
the condemning authority, or if 3. if neither Landlord nor Tenant elects to
terminate this Lease, as aforesaid, this Lease shall remain unaffected by such
condemnation or taking, except that Base Rent and Rent Adjustments shall abate
to the extent, if any, provided in this Section 13. In the event only a part of
the Premises shall be so condemned or taken and this Lease and the Term and
estate hereby granted with respect to the remaining  portion of the Premises are
not  terminated as hereinbefore provided, Landlord will, with reasonable
diligence and at its expense, restore the remaining portion of the Premises as
nearly as practicable to the same condition as it was in prior to such
condemnation or taking FN 11.4.

FN 11.1. through FN 11.4. - see page 11(a)

                                       11
<PAGE>

FN 11.1. - continued from Section 12.A.

and since 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 each insurance company which has issued,
or in the future may issue, its policies of fire, extended coverage or material
damage insurance written notice of the terms of this mutual waiver, and to have
such insurance policies properly endorsed, if necessary, to prevent the
invalidation of any of the coverage provided by such insurance policies by
reason of such mutual waiver.

FN 11.2. - continued from Section 12.B.

; provided, however, if Tenant maintains insurance on a "claims made" basis,
Tenant shall be obligated to maintain such insurance, as set forth herein, for a
period of no less than two (2) years after the Expiration Date or any extension
thereto, and (b) standard so-called "all-risk" property insurance covering all
Tenant's personal property, trade fixtures and any improvements not covered by
Landlord's insurance, and (c) excess liability insurance with minimum coverage
of $19,000,000.00;

FN 11.3. - continued from Section 13.A.

and the part taken is substantial enough that the taking would destroy the
marketability of the Building, as determined by Landlord in its reasonable
judgment,

FN 11.4. - continued from Section 13.A.

; provided, however, that Landlord shall have no obligation to repair, replace
or restore the Tenant's furniture, equipment or other personal property and that
Landlord shall repair, replace and restore the Initial Alterations and the
Alterations, but only to the extent that Landlord actually receives condemnation
proceeds on account thereof. Landlord agrees to make and diligently purse a
claim for condemnation proceeds sufficient to repair, replace or restore the
Initial Alterations and the Alterations. If (i) the grade of any street or alley
adjacent to the Building or Real Property is changed by any competent authority,
and (ii) such change of grade makes it necessary to remodel the Building to
conform to the changed grade, and (iii) in Landlord's judgment, termination of
this Lease is necessary to accomplish such remodeling, Landlord shall have the
right to terminate this Lease upon not less than one hundred eighty (180) days
notice prior to the date of termination designated in said notice.

                                     11(a)
<PAGE>

        B. In the event of their termination in any of the cases hereinbefore
provided, this Lease and the Term and estate hereby granted shall expire as of
the date of such termination with the same effect as if that were the Expiration
Date, and Base Rent and Rent Adjustments shall be accordingly apportioned.

        C. In the event of any such condemnation or taking hereinbefore
mentioned of all or a part of the Building or Real Property, Landlord shall be
entitled to receive the entire award in the condemnation proceeding, including
any award made for the value of the estate vested by this Lease in Tenant FN
12.1. and Tenant hereby expressly assigns to Landlord any and all right, title
and interest of Tenant now or hereafter arising in or to any such award or any
part thereof, and Tenant shall be entitled to receive no part of such award FN
12.2. Further, Tenant shall have no right to share in any judgment for damages
caused by the grade of any street or alley adjacent to the Building or Real
Property. No money or other consideration shall be payable by Landlord to Tenant
for any termination by Landlord pursuant to this Section 13.

        D. For purposes of this Section 13, the terms "condemned",
"condemnation", "taken" or "taking" shall include a voluntary conveyance by
Landlord to the condemning authority under threat of condemnation and the term
"award" shall include the consideration paid by the condemning authority for
such deed.

     14.       Assignment-Subletting.

           FN 12.3.

FN 12.1. through FN 12.3. - see pages 12(a) - 12(c)

                                       12
<PAGE>

FN 12.1. - continued from Section 13.C.

(except as otherwise provided below in this Section 13.C.)

FN 12.2. - continued from Section 13.C.

; provided, however, that, subject to the rights of third parties under Section
16 of this Lease, Tenant may proceed independently in such proceeding but only
for (i) the unamortized portion of the leasehold improvements for which Tenant
has paid in their entirety, (ii) the relocation costs of Tenant, and (iii) the
value of Tenant's leasehold estate (based upon the portion of the Premises
condemned or taken and the Term remaining at the time of the condemnation or
taking), but in any case, only if any such award is in addition to and not in
diminution of the award of Landlord.

FN12.3. - continued from Section 14

        A.     Tenant may not, without the consent of Landlord:

               1. assign, hypothecate, mortgage, encumber, or convey this Lease;
provided, however, Tenant may, without the consent of Landlord, assign this
Lease to any entity which has acquired all of the assets of Tenant by virtue of
merger, consolidation, purchase, or other direct transfer, provided that after
such acquisition, such entity has substantially the same net worth as Tenant as
of the date of this Lease ("Successor"), it being understood that Tenant shall
deliver to Landlord copies of the fully executed assignment and any related
documentation within thirty (30) days after complete execution of the
assignment;

               2. allow any transfer thereof of any lien upon the interest of
Tenant by operation of law;

               3. permit the use or occupancy of the Premises or any part
thereof by anyone other than Tenant, except to the extent provided in this
Section 14.

        B. Assignment.

               1. In order for Tenant to obtain the consent of Landlord to an
assignment of this Lease for the remaining Term, Tenant shall submit to
Landlord:

                      a. the proposed assignment (executed by Tenant and
assignee), which is not to commence prior to the first day of the month
immediately following the month in which the thirtieth (30th) day following the
submission to Landlord occurs; and

                      b. sufficient information to permit Landlord to determine
the acceptability of the financial responsibility of the proposed assignee, if
Tenant is seeking to be released from liability hereunder, and whether the
character of the proposed assignee will adversely affect Landlord's ability to
market the Building as first-class office or retail space.

                                     12(a)
<PAGE>

        2. Landlord shall not unreasonably withhold its consent to an
assignment, provided that Tenant agrees that Landlord shall be acting reasonably
when such consent is not granted if:

               a. in the reasonable judgment of Landlord the character of the
proposed assignees will adversely affect Landlord's ability to market the
Building as a first-class downtown Chicago office building or any space
contained therein as first-class office or retail space;

               b. in the reasonable judgment of Landlord the purpose for which
the assignee intends to use the Premises is not in keeping with the standards of
Landlord for the Building, or is in violation of the terms of any other leases
in the Building, it being understood that the purpose for which assignee intends
to use the Premises may not be in violation of this Lease;

               c. the assignee is either a government (or subdivision or agency
thereof) or an occupant of the Building, provided that with respect to an
occupant of the Building, Landlord must be reasonable in determining whether to
grant its consent if no other reasonably comparable space in the Building is
available to such proposed assignee;

               d. less than the entire Lease, or the entire Lease for less than
the remaining Term is being assigned;

               e. if Tenant is seeking to be released from liability hereunder,
the assignee is not, in the reasonable judgment of Landlord, solvent or does not
have unencumbered assets of a value at least equal to twice the projected cost
of the obligations to be assumed for the unexpired Term;

               f.  Tenant is in default under this Lease.

        3. For purposes of this Section 14.B. an assignment shall be deemed to
include a change in the majority control of Tenant, if Tenant is a partnership
or a corporation whose stock is not traded publicly. The withholding of consent
by Landlord to any assignment shall not affect or diminish any right of Tenant
to sublet all or any part of the Premises. Notwithstanding anything contained
herein to the contrary, Tenant shall remain primarily liable under this Lease
following any assignment, unless Tenant is specifically released from liability
by Landlord in writing.

     C. Subletting. Tenant shall have the right, without Landlord's consent , to
sublet all or any portion of the Premises (the entire Premises or any portion of
the Premises if a sublet of less than all of the Premises is desired being
hereinafter referred to as "Subject Premises"), provided that Tenant shall
deliver to Landlord copies of the fully executed sublease and any related
documentation within thirty (30) days after complete execution of the sublease.

     D. If Tenant sublets the Premises or any portion thereof or assigns the
Lease (with Landlord's consent, if required under this Section 14):

        1. the terms and conditions of this Lease, including among other things,
the use provisions and the liability of Tenant for the Subject Premises or

                                     12(b)
<PAGE>

the Premises (as the case may be), shall in no way be deemed modified, abrogated
or amended.

        2. the consent of Landlord to an assignment shall not be deemed a
consent to any further assignments by either Tenant, subtenants or assignees.

        3. Tenant shall pay Landlord as additional Base Rent, sixty percent
(60%) of any excess rent (together with escalation) payable to and collected by
Tenant under the sublease or assignment over the Base Rent pus Rent Adjustments
payable to Landlord under this Lease, except that Tenant shall not be required
to pay Landlord any portion of any excess rent arising out of a subletting of
the 10th floor or any portion thereof. Notwithstanding any other provisions of
this Lease, there shall be no abatement or reduction of Base Rent or Rent
Adjustments as a result of amounts payable pursuant to this Section 14.D.3. Such
excess rent shall first be reduced by one hundred percent (100%) of the
following:

               a. brokerage commissions;

               b. advertising and legal expenses involved in the subletting or
assignment or in subsequently enforcing the terms of the sublease or assignment;
and

               c. the actual expenditures of Tenant for improvements it is
required to make as a result of the sublease or assignment.

        4. in the case of a sublease, the sublease must contain default
provisions similar to those contained in this Lease and in the event of a
default under the sublease Tenant agrees to use reasonable efforts to promptly
enforce such provisions if such default affects the safety or operation of the
Building or its Systems or structure or the quiet enjoyment of any other tenants
of their respective premises.

                                     12(c)
<PAGE>

        15.  Waiver of Claims and Indemnity.

               A. 1. To the extent permitted by law, Tenant releases Landlord
Related Parties (defined in Section 15.E.1.) from, and waives all claims for,
damage to person or property sustained by Tenant or any occupant of the Building
or Premises resulting from the Building or Premises or any part of either or any
equipment or appurtenance becoming out of repair or resulting from any accident
in or about the Building, or resulting directly or indirectly from any act or
omission of any tenant or occupant of the Building or any other person, other
than Landlord Related Parties. This Section 15 shall apply especially, but not
to exclusively, to the flooding of basements or other subsurface areas, and to
the damage caused by refrigerators, sprinkling devices, air-conditioning
apparatus, water, snow, frost, steam, excessive heat or cold, falling plaster,
broken glass, sewage, gas, odors or noise, or the bursting or leaking of pipes
or plumbing fixtures and shall apply equally whether such damage be caused or
result from any thing or circumstances above mentioned or referred to, or any
other thing or circumstance whether of a like nature or of a wholly different
nature.

                        2. The Landlord  Related  Parties  shall not be liable,
to the extent of the recovery by Tenant under any property damage insurance
carried by it (whether or not required to be carried by the terms of this
Lease), or if Tenant has made a reduction in the insurance which Tenant is
required to keep in force pursuant to Section 12, to the extent of the recovery
Tenant would have had if Tenant had not made such reduction, for any loss or
damage to property even if due to the negligence, gross negligence or
intentional misconduct of any of the Landlord Related Parties. Tenant shall make
diligent efforts to recover from its insurers the full amount of any insured
claim.

        B. 1. To the extent permitted by law, Landlord releases Tenant Related
Parties (defined in Section 15.E.2.) from, and waives all claims for, damage to
person or property sustained by Landlord or any occupant of the Building or
Premises resulting from the Building or Premises or any part of either or any
equipment or appurtenance becoming out of repair or resulting from any accident
in or about the Building, or resulting directly or indirectly from any act or
omission of any tenant or occupant of the Building or of any other person, other
than Tenant Related Parties. This Section 15 shall apply especially, but not
exclusively, to the flooding of basements or other subsurface areas, and to
damage caused by refrigerators, sprinkling devices, air-conditioning apparatus,
water, snow, frost, steam, excessive heat or cold, falling plaster, broken
glass, sewage, gas, odors or noise, or the bursting or leaking of pipes or
plumbing fixtures and shall apply equally whether such damage be caused or
result from any thing or circumstance above mentioned or referred to, or any
other thing or circumstance whether of a like nature or of a wholly different
nature. If any such damage, whether to the Premises or to the Building or any
part thereof, or whether to Landlord or to other tenants in the Building,
results from any negligence of Tenant Related Parties, its invitees or
customers, except as provided in Section 15.B.2., Tenant shall be liable
therefor and Landlord may, at the option of Landlord, repair such damage and
subject to Section 15.B.2., Tenant shall, upon demand by Landlord, reimburse
Landlord forthwith for the total expense of such repairs.

For a continuation of Section 15, see page 13(a)

                                       13
<PAGE>

               2. The Tenant Related Parties shall not be liable to Landlord to
the extent of the recovery by Landlord to the extent of the recovery by Landlord
under any property damage or rent loss insurance carried by it (whether or not
required to be carried by the terms of this Lease), or if Landlord has made a
reduction in the insurance which Landlord is required to keep in force pursuant
to Section 35, to the extent of the recovery Landlord would have had if Landlord
had not made such reduction, for any loss or damage to any person or property
even if due to the negligence, gross negligence or intentional misconduct of any
of the Tenant Related Parties. Landlord shall make diligent efforts to recover
from its insurers the full amount of any insured claim.

        C. Except as provided in Section 15.B.2., Tenant agrees to indemnify and
save all of the Landlord Related Parties harmless against any and all claims,
demands, liabilities, costs and expenses, including, without limitation,
reasonable attorney's fees for the defense thereof, arising 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 pursuant to the terms of this Lease, or from
any negligence on any of the Tenant Related Parties in or about the Building or
Premises. In case of any action or proceeding brought against any of the
Landlord Related Parties by reason of such claim, upon notice from Landlord,
Tenant covenants to defend such action or proceeding by counsel reasonably
satisfactory to Landlord. Except as provided in Section 15.A.2., Landlord agrees
to indemnify and save all of the Tenant Related Parties harmless against any and
all claims, demands, liabilities, costs and expenses, including, without
limitation, reasonable attorneys' fees for the defense thereof, arising from any
breach or default on the part of Landlord in the performance of any covenant or
agreement on the part of Landlord to be performed pursuant to the terms of this
Lease (subject to Force Majeure), or from any negligence of any of the Landlord
Related Parties in or about the Building or Premises. In case of any action or
proceeding brought against any of the Tenant Related Parties by reason of any
such claim, upon notice from Tenant, Landlord covenants to defend such action or
proceeding by counsel reasonably satisfactory to Tenant.

        D. Nothing contained in this Section 15 or in this Lease shall require
Landlord Related Parties or Tenant Related Parties to release, indemnify, or
waive claims against the other for liability caused by negligence or intentional
misconduct of the other, it being understood that subject to Sections 15.A.2.
and 15.B.2., each respective party shall be responsible for its own negligent or
intentional misconduct.

        E. For purpose of this Section 15:

               1. "Landlord Related Parties" means Landlord, JMB/MS Management
Co., the beneficiaries of Landlord, the partners which comprise the
beneficiaries of Landlord, the partners which comprise such partners, and the
agents, employees, officers, directors, shareholders, partners or principals
(disclosed or undisclosed) of any of them.

               2. "Tenant Related Parties" means Tenant or the officers,
directors, shareholders, agents and employees of Tenant.

                                     13(a)
<PAGE>

   16. Mortgage-Ground Lease. Landlord may execute and deliver a mortgage or
trust deed in the nature of mortgage, both sometimes hereinafter referred to as
"Mortgage," against the Building, the Real Property or any interest therein, and
may sell and lease back the underlying land on which the Building is situated.
If requested by the mortgagee or trustee or by the lessor of any ground or
underlying lease (ground lessor), Tenant will either subordinate its interest in
this Lease to said Mortgage, or ground or underlying lease or make its interest
in this Lease superior, and will execute such agreement or agreements as may be
reasonably required by such mortgagee, trustee or ground lessor FN 14.1.

   It is further agreed:

        A. Should any mortgage affecting the Building or the Real Property be
foreclosed or if any ground or underlying lease be terminated:

               1. The liability of the mortgagee, trustee or purchaser as such
foreclosure sale or the liability of a subsequent owner designated as Landlord
under this Lease shall FN 14.2. exist only so long as such trustee, mortgagee,
purchaser or owner is the owner of the Building or Real Property and such shall
not continue or survive after further transfer of said ownership.

               2. Upon request of the mortgagee or trustee, Tenant will attorn
as Tenant under this Lease, to the purchaser at any foreclosure sale thereunder
FN 14.3. or if any ground or underlying lease be terminated for any reason,
Tenant will attorn as Tenant under this Lease to the ground lessor under the
ground lease FN 14.4. and will execute such i8nstruments as may be necessary or
appropriate to evidence such attornment FN 14.5.

FN 14.1. through FN 14.5. - see page 14(a)

                                       14
<PAGE>

FN 14.1. - continued from Section 16

; provided, however, that Tenant shall not be required to subordinate its
interest in this Lease unless the mortgage (or trustee) or ground lessor shall
provide Tenant with a Non-Disturbance and Attornment Agreement providing
substantially the same rights and obligations as the form attached hereto as
Exhibit "F".

FN 14.2. - continued from Section 16.A.1.

, provided that the transferee of such mortgagee, trustee, purchaser at a
foreclosure sale or subsequent owner designated as Landlord under this Lease
assumes the obligations of Landlord under this Lease,

FN 14.3. - continued from Section 16.A.2.

provided that such purchaser assumes and performs the obligations of Landlord
hereunder,

FN 14.5. - continued from Section 16.A.2.

(but only if Tenant has received an agreement providing substantially the same
rights and obligations as the form attached hereto as Exhibit "F" executed by
such mortgagee, trustee, ground lessor or purchaser at a foreclosure sale).

                                     14(a)
<PAGE>

        B. This Lease may not be modified or amended except as provided so as to
reduce the Base Rent and/or Rent Adjustments, or shorten the Term, or so as to
adversely affect in any other respect to any material extent the rights of
Landlord, nor shall this Lease be cancelled or surrendered, without he prior
written consent, in each instance, of the ground lessor or mortgagee.

        FN 15.1.

    17. Certain Rights Reserved to Landlord. Landlord reserves and may exercise
the following rights without affecting the obligations of Tenant hereunder:

        A. to change the name or street address of the Building FN 15.2.

        B. subject to Section 30 to install and maintain a sign or signs on the
exterior of the Building;

        C. to have access for Landlord and the other tenants of the Building to
any mail chutes located on the Premises according to the rules of the United
States Post Office;

        D. to decorate, remodel, repair, alter or otherwise prepare the Premises
for reoccupancy if Tenant vacates the Premises prior to the Expiration Date FN
15.3.

        E.  to retain pass keys at all times to the Premises FN 15.4.

        F. to grant to anyone the exclusive right to conduct any business or
undertaking in the Building  FN 15.5.

        G.  to exhibit the Premises to FN 15.6.

        H. to close the Building after regular working hours and on Holidays
subject, however, to the right of Tenant to admittance, under such reasonable
regulations as Landlord may prescribe from time to time which may include by way
of example but not of limitation, that persons entering or leaving the Building
identify themselves to a watchman by registration or otherwise and that said
persons establish their right to enter or leave the Building:

        I. to approve the weight, size and location of safes or other heavy
equipment or articles, which articles may be moved in, about, or out of the
Building or Premises only at such times and in such manner as Landlord shall
direct and in all events, however, at the sole risk and responsibility of
Tenant;

        J. to take any and all measures, including inspections, repairs,
alterations, decorations, outside the Premises, additions and improvements to
the Premises or to the Building, as may be necessary for the safety, protection
or preservation of the Premises FN 15.7.

        FN 15.8. Landlord may enter upon the Premises and may exercise any or
all of the foregoing rights hereby reserved without being deemed guilty of an
eviction or disturbance of the use or possession by Tenant and without being
liable in any manner to Tenant (except as provided in Section 15.D.) and without
abatement of Base Rent or Rent Adjustments or affecting any of the obligations
of Tenant hereunder.

     18. Holding Over. If Tenant retains possession of the Premises or any part
thereof after the termination of the Term or any extension thereof, by lapse of
time or otherwise, on the first day of each month Tenant so retains possession,
Tenant shall pay Landlord the Installments of Base Rent, and the estimate of
Landlord of Rent Adjustments, both at double the rate payable for the month
immediately preceding said holding over computed on a per-month basis, for each
month or part thereof (without reduction for any partial month) that Tenant thus
remains in possession, and in addition thereto, Tenant shall pay Landlord all
damages, consequential as well as directly sustained by reason of the retention
by Tenant of possession. The provisions of this Section do not exclude the right
of Landlord of re-entry or any other right hereunder.

FN 15.1. through FN 15.8. - see pages 15(a) and 15(b)

                                       15
<PAGE>

FN 15.1. - continued after Section 16.B.

C. To the extent this Section 16 is inconsistent with Exhibit "F", Exhibit "F"
shall be deemed controlling.

D. At the request of any mortgagee, trustee or ground lessor, Tenant shall give
notice of any default by Landlord hereunder to such mortgagee, trustee or ground
lessor, and such mortgagee, trustee or ground lessor shall have the right to
cure such default within the applicable grace period provided herein, provided
that such grace period shall commence upon giving of such notice by Tenant.

FN 15.2. - continued from Section 17.A.

; provided, however, if Landlord proposes such a change, it shall be subject to
Tenant's approval which shall not be unreasonably withheld, provided further,
however, that either a tenant in the Building or Landlord may refer to the
Building or use the Madison Street address without Tenant's approval;

FN 15.3. - continued from Section 17.E.

; provided, however, Landlord shall give Tenant at least thirty (30) days
advance notice of such work to be performed in the Premises;

FN 15.4. - continued from Section 17.F.

except to those areas within the Premises designated by Tenant as Secured
Area(s) pursuant to Section 34 of this Lease;

FN 15.5. - continued from Section 17.G.

; provided, however, that the granting of such exclusive rights shall not: 1.
restrict or interfere with Tenant's ability to conduct its business on the
Premises, or to use the Premises as provided for under this Lease or 2. require
Tenant to do business with any other Tenant in the Building;

FN 15.6. - continued from Section 17.H.

prospective tenants during the last twelve (12) months of the Term; provided,
however, Landlord shall use reasonable efforts to give Tenant reasonable advance
notice of such exhibition;

FN 15.7. - continued from Section 17.K.

, or as may be necessary or desirable for the safety, protection or preservation
of the Real Property (other than the Premises) or in the interests of the
Landlord, or as may be necessary or desirable in the operation of the Real
Property; provided, however, Landlord shall use reasonable efforts to give
Tenant advance notice if Landlord intends to exercise its rights under this
Section 17.K. within the Premises.

                                     15(a)
<PAGE>

FN 15.8. - continued at the beginning of the last paragraph of Section 17.

Subject to the provisions of Section 10 of this Lease regarding entry into
the Premises by Landlord,

                                     15(b)
<PAGE>

     19. Remedies of Landlord. All rights and remedies of Landlord herein
enumerated shall be cumulative, and none shall exclude any other right or remedy
allowed by law.

        A. FN 16.1.

        B. If Tenant defaults in the payment of Base Rent, Rent Adjustment
Deposits or Rent Adjustments, or in payment of any other amount due Landlord and
Tenant does not cure the default within twenty (20) days after written demand
for payment of such Base Rent, Rent Adjustment Deposits or Rent Adjustments or
other amounts due Landlord or if Tenant defaults in the prompt and full
performance of any other provisions of this Lease, and Tenant does not cure the
default within forty-five (45) days after written demand by Landlord that the
default be cured (unless the default involves a hazardous condition, which shall
be cured forthwith) or if the leasehold interest of Tenant be levied upon under
execution or be attached by process of law and such levy or attachment is not
released within ninety (90) days, or if Tenant makes an assignment for the
Benefit of creditors or admits its inability to pay its debts, or if a receiver
be appointed for any property of Tenant, or if Tenant abandons the Premises,
then and only in any such event Landlord may, is Landlord so elects but not
otherwise, and after notice of such election, either forthwith terminate this
Lease and the right to possession of the Premises by Tenant or, without
terminating this Lease, forthwith terminate the right to possession of the
Premises by Tenant FN 16.2.

        C. At the Expiration Date or upon any termination of this Lease, whether
by lapse of time or otherwise, or upon any termination of the right to
possession by Tenant without termination of this Lease, Tenant shall surrender
possession and vacate the Premises immediately, and deliver possession thereof
to Landlord, and hereby grants to Landlord full and free license to enter into
and upon the Premises in such event with process of law and to repossess
Landlord of the Premises as of the former estate of Landlord 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, without being deemed in any manner guilty
of trespass, eviction or forcible entry or detainer, and without relinquishing
the rights of Landlord to Base Rent or Rent Adjustments or any other right given
to Landlord hereunder or by operation of law.

        D. Landlord may elect to terminate the right to possession by Tenant
only, without terminating this Lease, if Tenant fails to occupy or take
possession of the Premises or fails to conduct its business activities in the
Premises or abandons or vacates the Premises or otherwise entitles Landlord so
to elect. Further, Landlord may elect to enter into the Premises, remove the
signs of Tenant and other evidences of tenancy, and to take and hold possession
thereof as in subsection C. of this Section 19 provided, without such entry and
possession terminating this Lease or releasing Tenant, in whole or in part, from
the obligation of Tenant to pay Base Rent or Rent Adjustments hereunder the full
Term. Upon and after entry into possession without termination of the Lease,
Landlord shall take reasonable measures to mitigate damages recoverable against
Tenant and shall use reasonable efforts to relet the Premises or any

FN 16.1. and FN 16.2. - see page 16(a) - 16(b)

                                       16
<PAGE>

FN 16.1. - continued from Section 19.A.

        A. To the extent permitted by law, if, at any time during the Term,
Tenant who is then the holder of this Lease (or any guarantor of the obligations
of Tenant under this Lease) becomes a debtor or debtor-in-possession under any
Chapter of Title 11 of the United States Code 11 U.S.C. Sections 101 et. Seq.
("Code"), or any other federal statute pertaining to bankruptcy, whether by
voluntary or involuntary proceedings (except where an involuntary petition shall
be filed against Tenant, if it is vacated or withdrawn within sixty (60) days
[plus any extension of time granted in such bankruptcy proceedings]), makes a
general assignment of its assets for the benefit of its creditors, or enters
into any other court supervised or out-of-court restructuring or work-out of its
liabilities, or if a receiver, liquidator, trustee or assignee is appointed to
administer all or a portion of Tenant's assets (except where such receiver shall
be appointed in an involuntary proceeding, and be withdrawn within sixty [60]
days [plus any extension of time granted in such bankruptcy proceeding] of his
appointment), or if the leasehold interest of Tenant is levied upon under
execution or is attached by process of law, then and in any such event this
Lease shall forthwith terminate without notice and without entry or other action
by Landlord. Upon such termination Landlord shall be entitled to its remedies
upon termination as set forth in Section 19.B.

FN 16.2. - continued from Section 19.B.

; provided, however, if Tenant defaults in any provisions of this Lease other
than the payment of Base Rent, Rent Adjustment Deposits, Rent Adjustments or any
other amount due Landlord, which shall be governed as stated, or other than a
default which involves a hazardous condition or a default pursuant to Section
7.F., which shall be cured forthwith, and if Tenant, within the forty-five (45)
day period referred to above, gives Landlord evidence which is satisfactory, in
the reasonable judgment of Landlord, that Tenant is diligently pursuing a course
which will remedy the default which is the subject of the notice, such default
shall be deemed remedied, but provided further, that (i) if after one hundred
twenty (120) days elapse from the date of the original notice of the default
such default has not been cured, or (ii) if Tenant fails to give Landlord
satisfactory evidence, within the forty-five (45) day period referred to above,
that Tenant is diligently pursuing a course which will remedy the default,
Landlord shall thereupon again have to right to serve notice of default as
provided in this Section 19.B. and under such circumstances Tenant shall not
have the right to cure the default beyond such forty-five (45) day period or to
evidence diligent remedying of the default to avoid its consequences and
Landlord shall be entitled immediately after giving such notice to exercise all
of its remedies under this Lease with respect to such default. If Landlord
terminates this Lease and the Term created hereby, pursuant to this Section 19,
or if such termination occurs pursuant to Section 19.A., Landlord may forthwith
repossess the Premises and shall be entitled to recover forthwith, in addition
to any other sums or damages for which Tenant may be liable to Landlord, as
damages a sum of money equal to the excess of the present value of the Base Rent
plus Rent Adjustments provided to be paid by Tenant for the balance of the Term
over the present value of the then reasonable rental value of the Premises
(after deductions of all anticipated expenses of reletting) for said period. For
purposes of determining present value, Landlord and Tenant agree to use a
discount rate equal to the lower of the average published prime rate (or its
equivalent) of

                                     16(a)
<PAGE>

interest then in effect at Continental Illinois National Bank and Trust Company
of Chicago, The first National Bank of Chicago and Harris Trust and Savings
Bank, or the maximum legal rate of interest. Should the present value of the
then reasonable rental value of the Premises (after deduction of all anticipated
expenses of reletting) for the balance of the Term exceed the present value of
the Base Rent plus Rent Adjustments provided to be paid by Tenant for the
balance of the Term, Landlord shall have no obligation to pay to Tenant the
excess or any part thereof or to credit such excess or any part thereof against
any other sums or damages for which Tenant may be liable to Landlord.

                                     16(b)
<PAGE>

part thereof for the account of Tenant to any person, firm or corporation other
than Tenant, for such Base Rent, for such time and upon such terms as Landlord,
in its reasonable discretion, shall determine, and Landlord shall not be
required to accept any tenant offered by Tenant or to observe any instructions
given by Tenant about such reletting. In any such case, Landlord may make
repairs, alterations and additions in or to the Premises, and redecorate the
same to the extent deemed by Landlord reasonably necessary or desirable, and
Tenant shall, upon demand, pay the expense thereof, together with the expenses
of Landlord of the reletting. If the consideration collected by Landlord upon
any such reletting for the account of Tenant is not sufficient to pay monthly
the full amount of the Base Rent and Rent Adjustments reserved in this Lease,
together with the expenses of repairs, alterations, additions, redecorating and
the expenses of Landlord, Tenant shall pay to Landlord the amount of each
monthly deficiency upon demand.

        E.  Intentionally Omitted.

        F. Any and all property which may be removed from the Premises by
Landlord pursuant to the authority of the Lease or of 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 to Landlord, upon
demand, any and all expenses incurred in such removal and all storage charges
against such property so long as the same shall be in possession of Landlord or
under the control of Landlord. Any such property of Tenant not retaken from
storage by Tenant at the end of the Term, however terminated, 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.

        G. Tenant hereby grants Landlord a first lien upon the interest of
Tenant under this Lease to secure the payment of moneys due under this Lease,
which lien may be enforced in equity; and Landlord shall be entitled as a matter
of right to have a receiver appointed to take possession of the Premises and
relet the same under order of court.

        H. Landlord or Tenant shall pay upon demand all the costs, charges and
expenses of the other, including the fees of counsel, agents and others
retained, incurred in enforcing the obligations of the other hereunder if the
enforcing party prevails. If, however, either party causes the other party to
become involved or concerned in any litigation, negotiation or transaction,
without the fault of the other such party, such party shall pay the other party,
upon demand, all of such other party's costs, charges and expenses, including
the fees of counsel, agents and others retained, incurred in connection with
such litigation, negotiation or transaction, regardless of who prevails.
Additionally, if Tenant, on a repetitive basis, defaults under this Lease, so
that Landlord, on a repetitive basis, is required to serve default notices on
Tenant, Tenant shall pay Landlord a fee for each default notice served as
reimbursement to Landlord for costs and expenses incurred in serving such
default notices FN 17.1.

        20. Intentionally Omitted.

        21. Surrender of Possession. At the Expiration Date or other termination
of the Term, or the right of Tenant to possession hereunder. Tenant shall quit
and surrender the Premises to Landlord. broom clean, in good order and
condition, ordinary wear and damage by fire or other casualty excepted, and
Tenant shall remove all of its property FN 17.2. If Tenant does not remove its
property of every kind and description from the Premises prior to the end of the
Term, however ended. Tenant shall be conclusively presumed to have conveyed the
same to Landlord under this Lease as a bill of sale without

FN 17.1. through FN 17.2. - see page 17(a)

                                       17
<PAGE>

FN 17.1. - continued from Section 19>H.

; provided that Tenant shall not be obligated to pay for the first three (3)
default notices served to Tenant under this Lease.

FN 17.2. - continued from Section 21.

including, without limitation, the property which Landlord requires that Tenant
remove pursuant to Section 9.K. Tenant shall repair any damage, other than the
ordinary minor damage incidental to an office tenant vacating office space,
caused by the removal of its property from the Premises.

                                     17(a)
<PAGE>

further payment or credit by Landlord to Tenant and Landlord may remove the same
and Tenant shall pay the expense of such removal to Landlord upon demand. The
obligation of Tenant to observe or perform this covenant shall survive the
Expiration Date or other termination of the Term.

        22. Notices. All notices shall be in writing unless otherwise specified.

            A. Notices shall be effectively served by Landlord upon Tenant by
forwarding via Certified or Registered Mail, postage prepaid, to Tenant at the
Premises, Attn: the President, with separate copies to be forwarded as follows:

               1. to the Premises:

                    a.  Attn:  David O'Gorman
                        Senior Vice President of Administrations and
                        Finance; or
                        Tenant's Senior Vice President of
                        Administrations and Finance form time to time;

                    b.  Attn:  the Real Estate Representative specified by
                        Tenant (if one has been Designated to Landlord in a
                        notice from Tenant); and

                    c.  Attn:  Legal Department

               2.  Goldberg, Kohn, Bell, Black, Rosenbloom & Morris, Ltd.
                   Attorneys -at -Law
                   55 East Monroe Street
                   Suite 3900
                   Chicago, Illinois  60603
                   Attention:  James B. Rosenbloom, Esquire

Or to such other address as Tenant mat direct in writing. The time of notice
shall be three (3) business days after the time of mailing. If at any time
during the Term Tenant's Senior Vice President of Administrations and Finance
changes, Tenant shall immediately notify Landlord of such changes.

            B. Notices shall be effectively served by Tenant upon Landlord when
addressed to Landlord and served;

               1.  Upon an officer of Landlord; and

               2.  Certified or Registered Mail, postage prepaid, to Landlord in
care of JMB/MS Management Co., Suite 1200, 111 East Wacker Drive, Chicago,
Illinois 60601, Attention: Legal Department or if notified of another address by
Landlord, at such later address, in which case three (3) business days after the
time of mailing shall be the time of notice.

        23. Intentionally Omitted.

        24. Intentionally Omitted.

                                       18
<PAGE>

        25. Registered Agent

          A.  Tenant shall at all times during the Term of this Lease have a
registered agent for service of process in Illinois. Tenant hereby appoints Carl
A. Royal, or Tenant's general counsel form time to time, 30 South Wacker Drive,
Chicago, Illinois 60606, as its true and lawful registered agent for service of
process.

          B.  If at any time the during the Term Tenant's registered agent in
Illinois and/or registered office changes (including without limitation its
general counsel from time to time), Tenant shall immediately notify Landlord of
such change.

        26. Miscellaneous.

          A. No payment by Tenant or receipt by Landlord of lesser amount than
any Installment or payment of Base Rent, Rent Adjustment Deposits, Rent
Adjustments or other amounts due shall be deemed other than on account of the
amount due, and no endorsement or statement on any check or any transmittal
document accompanying any check or payment of any amount due shall be deemed an
accord and satisfaction.  Landlord may accept such check or payment without
prejudice to the right of the Landlord to recover the balance of any amount due
or pursue any other remedies available to Landlord.  No receipt of money by
Landlord from Tenant after the Expiration Date or termination of the Lease or
after the service of any notice or after the commencement of any suit, or after
final judgment for possession of the Premises shall reinstate, continue or
extend the Expiration Date of Term or affect any such notice, demand or suit.

          B. No waiver of any default of Tenant or Landlord hereunder shall be
implied from any omission by Landlord or Tenant to take any action on account of
such default if such default persists or be repeated, and no express waiver
shall affect any default other than the default specified in the express waiver
and that only for the time and to the extent therein stated.

          C. The word "Landlord" and "Tenant" wherever used in this Lease shall
be construed to mean plural where necessary grammatical changes required to make
the provisions hereof apply either to corporations or individuals, men or women,
shall in all cases be assumed as though in each case fully expressed.

          D. 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 in the event
this Lease has been assigned with the express written consent of Landlord.

          E. Submission of this Lease for examination does not constitute a
reservation of or option for the Premises. This Lease does not become effective
as a lease or otherwise until execution and delivery by both Landlord and Tenant
FN 19.1

          F. All amounts owed by Tenant to Landlord shall be deemed additional
Base Rent and ( unless otherwise provide, and other than the Base Rent, Rent
Adjustments Deposits and rent Adjustments, which shall be due as provided) be
paid within twenty (20) days from the date Landlord renders a statement of
account.  All such amounts (including Base Rent, Rent Adjustment Deposits and
Rent Adjustments) shall bear interest from twenty (20) days after date paid at
the average published prime rate (or its equivale) of interest in effect on the
date due at the Continental Illinois National Bank and Trust Company of Chicago,
The First National Bank of Chicago and the Harris Trust and Savings (the "Prime
Rate") or at the maximum legal rate, if any, of interest for business loans,
whichever is lower.

          G. All exhibits attached to this Lease are hereby made a part of this
Lease as though inserted in this Lease.

          H. The headings of sections are for convenience only and do not limit
or construe the contents of the sections.

          I. If Tenant shall occupy the Premise prior to the Commencement Date
with the consent of Landlord, all the provisions of this Lease shall be in full
force and effect as soon as Tenant occupies the Premises.

          J. Subject to Section 16, should any mortgage, leasehold or otherwise,
requires modification of this Lease which will not bring about any increased
expense to Tenant or in any other way materially change the rights and
obligations of Tenant hereunder, Tenant agrees that this Lease may be so
modified.

FN 19.1. - see page 19(a)

                                       19
<PAGE>

FN 19.1. - continued after Section 26.E.

If all of the terms and conditions thereof are acceptable to Landlord, Landlord
shall use reasonable efforts to execute this Lease as soon as practicable after
receipt of a Lease duly executed by Tenant. In the event that Landlord does not
execute this Lease and deliver a copy thereof to Tenant within fifteen (15) days
after the same is executed by Tenant and received by Landlord, Tenant, at any
time prior to its receipt of a fully executed Lease from Landlord, shall have
the right to revoke delivery and withdraw its execution of this Lease by serving
Landlord with written notice thereof.

                                     19(a)
<PAGE>

          K. Landlord and Tenant each represent to the other that they have
dealt directly with and only with Metropolitan Structure and The Levy
Organization as brokers in connection with this Lease, and that insofar as such
party knows no other broker negotiated this Lease or is entitled to any
commission in connection therewith, Landlord will pay the commission owing to
Metropolitan Structure in connection with this Lease and will pay the commission
owing to the Levy Organization. Tenant indemnifies and holds Landlord, its
beneficiaries, Owner and the partners of Owner and their respective agents and
employees harmless from all claims of any other brokers claiming to have been
employed by or to have represented Tenant in connection with this Lease.
Landlord indemnifies and holds Tenant, its agents and employees harmless from
all claims of any other brokers claiming to have been employed by or to have
represented Landlord in connection with this Lease.

          J. Landlord and Tenant agrees from the time upon at least thirty (30)
days prior to request, to deliver to the other a written statement certifying:
1. that this Lease is unmodified and in full force and effect, if such be the
case (or if there have been modifications that the same is in full force and
effect as modified, if such be the case and identifying the modification). 2.
the dates to which the Base Rent and other charges have been paid, 3. that so
far as the person making the certificate knows, Landlord or Tenant (as the case
may be) is not in default under any provisions of this lease, if such the case
and 4. any other information and certifications reasonably requested by Tenant
or Landlord, ground lessor or mortgage (a the case may be).

          M. The title of Landlord or Owner is and always shall be paramount to
the title of Tenant, and nothing herein contained shall empower Tenant to do any
act which can, shall or may encumber such title FN 20.1

          N. The laws of the State of Illinois shall govern the validity,
performance, construction and enforcement of this Lease.

          O. If ant 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 of circumstances other than those as to which
it is held invalid or unenforceable, shall not be affected thereby and each
term, covenant or condition of this Lease shall be valid and be enforceable to
the fullest extent permitted by law.

          P. The term "Owner", as used in this Lease, means the beneficiary of
the Land Trust which owns title to the Real Property or the Building.  If such
beneficiary is a partnership, any liability or obligation of said partnership
under this Lease whether as beneficiary or Owner shall be limited to solely to
the assets of such Land Trust and no partner of said partnership shall be
individually or personally liable for any claim arising out of this Lease.  A
deficit capital account of any such partner shall not be deemed an asset or
property of said partnership.

          Q. If Tenant is a corporation, the persons executing this Lease on
behalf of such corporation hereby represent and warrant that they have been duly
authorized to execute this Lease for and on behalf of such corporation pursuant
to a duly adopted resolution of its board of directors or by virtue of its
bylaws.

          R. Landlord and Tenant agree that should Landlord, in the exercise of
its reasonable discretion, determine that a fire emergency exit (crash door) is
required in the interest of public safety, Landlord may, at its sole expense
install such fire emergency exit (crash door) in any demising wall of the
Premises.

          S. If Landlord is a bank as trustee under a trust, this Lease is
executed by the undersigned trustee, not personally but solely as trustee and
its expressly understood and agreed by the parties hereto, anything contained
herein to the contrary notwithstanding, that each and all of the covenants,
undertakings, representations and agreements herein made are made and intended,
not as personal covenants, undertakings, representations and agreements of the
trustee, individually, or for the purpose of binding it personally , but this
Lease is executed and delivered by the trustee, solely in the exercise of the
powers confirmed upon it as such trustee under said trust agreement and no
personal liability or personal responsibility is assumed by, nor shall at any
time be asserted or enforced against said bank, the beneficiary of said trust or
its Agent on account hereof, or on account of any covenant undertaking,
representation, warranty or agreement herein contained, either expressed or
implied, all such personal liability, if any, being hereby expressly waived and
released by the parties hereto or holder hereof, and by all persons claiming by
or through or under said parties or holder hereof.  Such trustee, hereby
confirms that its beneficiary has the authority to manage the Buildings and has
designated  JMB/MS Management Co. as Agent for the Beneficiary in connection
with the management of the Building.

          T. Intentionally Omitted.

FN 20.1 - see page 20 (a)

                                       20
<PAGE>

FN 20.1. - continued from Section 26.M.

, provided that either Landlord or Tenant may record a Memorandum of
Lease in form and substance acceptable to both Landlord and Tenant.

                                     20(a)
<PAGE>

          U. Landlord and Tenant agree, that to the extent permitted by law, for
possession actions only, each shall and hereby does waive trial by jury.

          V. Approvals, permission, elections or the consent of Landlord, or
Tenant (as case may be) under this lease must be in writing in order to be valid
and Landlord and Tenant agree that their respective approval or consent when
required under this Lease shall not be unreasonably withheld or delayed, except
to the extent that this Lease expressly sets forth a different standard for the
granting or withholding of such approval or consent.

          X. The liability or obligations of Metropolitan Structures under this
Lease, if any, shall be limited to its partnership assets and no partner of said
partnership shall be individually or personally liable for any claims arising
out of this Lease. A deficit capital account of any such partner shall not be
deemed an asset or property of said partnership.

          Y. Landlord represents that to the best of its knowledge, information
and belief, as of the date of this Lease, the Building and all Systems and fire
safety apparatus fully comply with all applicable laws, ordinances, governmental
regulations and fire safety requirements.

          Z. This Lease does not grant any rights to light or air over the
building.

          AA. The liability or obligations of JMB/MS Management Co. under this
Lease, if any, shall be limited to its partnership assets and no partner of said
partnership shall be individually or personally liable for any claim arising out
of this Lease. A deficit capital account of any such partner shall not be deemed
an asset or property of said partnership.

                                       21
<PAGE>

    27. Tenant Credit

          A. 1. As a concession to Tenant, Landlord hereby grants Tenant the
following credits in the aggregate amount of THREE MILLION SIX HUNDRED
TWENTY-EIGHT THOUSAND FOUR HUNDRED FIFTY-THREE AND 20/100 Dollars
($3,628,453.20) ("Rent Credit") to be applied against the following
Installments:

                           MONTH                  AMOUNT
                           -----                  ------

                      April, 1988           $      260,746.10
                      May, 1988                    260,746.10
                      June, 1988                   260,746.10
                      July, 1988                   260,746.10
                      August, 1988                 260,746.10
                      September, 1988              260,746.10
                      October, 1988                260,746.10
                      November, 1988               260,746.10
                      December, 1988               260,746.10
                      January, 1989                260,746.10
                      February, 1989               260,746.10
                      March, 1989                  260,746.10
                      April, 1989                   41,625.00
                      May, 1989                     41,625.00
                      June, 1989                    41,625.00
                      July, 1989                    41,625.00
                      August, 1989                  41,625.00
                      September, 1989               41,625.00
                      October, 1989                 41,625.00
                      November, 1989                41,625.00
                      December, 1989                41,625.00
                      January, 1990                 41,625.00
                      February, 1990                41,625.00
                      March, 1990                   41,625.00
                                            -----------------

                               Rent Credit  $    3,628,453.20

          2. a.  The monthly credits listed above are herein referred to as
"Installment Credits".  Installment  Credits  shall  only be  applied  against
Installments  to any other provisions of this Lease, the Installment Credit for
each month during which such an abatement occurs shall be applied to the portion
(if any) of the Installment of Base Rent for such month that is not abated, and
the portion of the Installment Credit for such month not applied against Base
Rent for such month by reason of such abatement (The "Deferred Installment
Credit") shall be applied toward Installments of non-abated Base Rent becoming
due as follows: the aggregate amount of Deferred Installment Credits (if any)
shall be applied as a credit toward successive Installments of Base Rent not
otherwise abated pursuant to this Lease, commencing with the Installment of Base
Rent for the month of April 1989 or the first month thereafter that Base Rent is
not otherwise abated, until the aggregate amount of Deferred Installment Credits
has been so applied. For example, if Base Rent for the entire Premises was
abated for the month of June, 1988 and for the first ten (10) days of July,
1988, then the aggregate amount of Deferred Installment

                                       22
<PAGE>

Credits would equal $346,470.85 ($260,746.10 for June, 1988 plus $85,724.75 for
the first ten (10) days of July, 1988). Such amount would than be applied as a
credit toward the following Installments:

                       MONTH                 AMOUNT
                       -----                 ------

                     April, 1989           $219,121.10
                     May, 1989              127,349.75
                                           -----------
                             Total         $346,470.85

It is understood that Deferred Installment Credits shall not be applied as a
credit toward Rent Adjustment Deposits, Rent Adjustments or any amount, other
than the Base Rent Installments, due and owing from Tenant to Landlord pursuant
to any provision of this Lease.

                b. Under no circumstances (including, without limitation a
termination of this Lease as a result of a default) shall Landlord be obligated
to pay Tenant cash or any other form of consideration on account of the
Installment Credits or the Deferred Installment Credits (if any), even if Tenant
will not otherwise receive the benefit of all or any portion of the Installment
Credits or the Deferred Installment Credits (if any).

          3. The balance of Base Rent, Rent Adjustment Deposits and/or Rent
Adjustments due for any month to which an Installment Credit or Deferred
Installment Credit (if any) is applied shall be paid as provided in Sections 2
and 3 of this Lease.

          B. 1. As an additional concession to Tenant, Landlord hereby grants
Tenant a credit ("Work Credit") in the amount of SEVEN MILLION SIX HUNDRED
TWENTY-FOUR THOUSAND SEVEN HUNDRED AND 00/100 Dollars ($7,624,700.00, this
amount is calculated as follows: [($45.00 X 175,660) - $300,000.00] plus
$20,000.00 to be applied in the following sequence:

              a. $73,074.56 (.416 X 175,660) to the cost of the preliminary
sprinkler grid in the Premises existing as of the date of the Lease; and

              b. $5,260.74 (.416 X 12,646) to the cost of the preliminary
sprinkler grid in the Support Space (as defined in the Support Space Supplement
attached hereto) existing as of the date of this Lease; and

              c. $29,686.54 to the cost of horizontal Venetian blinds purchased
form Landlord for all peripheral windows in the Premises; and

              d. the balance shall be applied to the cost of the Initial
Alterations (as defined in the Work Supplement) performed in the Premises
(including, but not limited to, the cost of space planning, design, related
architectural and engineering services and the preparation of Plans [as defined
in the Work Supplement] for the Initial Alterations performed in the Premises).

                                       23
<PAGE>

          2. Tenant shall be responsible for the performance of the Initial
Alterations. During construction of the Initial Alterations, upon receipt by
Landlord of waivers of mechanics' liens from the General Contractor and the
subcontractors (with respect to lienable items only); percentage completion
certificates from Tenant, Tenant's architect, its General Contractor, space
planner, engineer and other consultants as the case may be; a sworn contractors
affidavit form the General Contractor; and a written request to disburse from
Tenant containing an approval by Tenant of the work done and specifying each
party to whom Work Credit funds are to be disbursed and the amount of each
disbursement, Landlord shall disburse Work Credit funds directly to Tenant's
architect, space planner, engineer or other consultants or General Contractor or
subcontractors (as the case may be); provided, however, Landlord will only
disburse Work Credit funds at the end of each calendar month and only for the
cost of work done during the period beginning with the commencement of
construction and ending two years thereafter and with respect to which Landlord
receives the documents required under this subsection 27.B.2. on or before the
first day of such calendar month, and provided further, that Landlord shall be
obligated to disburse any portion of the Work Credit during the continuance of
an uncured material or monetary default under this Lease, and Landlord's
obligation to disburse shall only resume when and if such default is cured. If
practicable, subcontractor's mechanics lien waivers will cover all work for
which disbursements is requested. Otherwise, such waivers shall at least cover
all work for which previous draws have been made. There shall be no fee charged
to Tenant for the disbursing of Work Credit.

          3. Notwithstanding anything contained herein to the contrary, if
Landlord fails to disburse funds as required in subsection 27.B.2. above, and as
a result thereof Tenant disburses its own funds toward the Initial Alterations,
Landlord shall pay interest to Tenant on such funds from the date of such
disbursement by Tenant to the date the Work Credit is disbursed by Landlord, or
any portion thereof which would cover the amount then disbursed by Tenant, at
the average published prime rate (or its equivalent) of interest in effect on
the date the Work Credit would other wise have been due, at the Continental
Illinois National Bank and Trust Company of Chicago, The First National Bank of
Chicago and the Harris Trust and Savings Bank or the maximum legal rate, if any,
of interest for business loans, whichever is lower.

          4. Upon completion of the Initial Alterations Tenant shall furnish
Landlord with: a. Tenant, General Contractor, and architectural completion
affidavits, b. full and final waivers of lien, c. receipted bills covering all
labor and materials expended and used, d. other appropriate documents evidencing
completion of the Initial Alterations, and f. a representation from Tenant to
the best of its knowledge and a certification by Tenant's architect, that the
Initial Alterations were constructed in accordance with the Plans and all
applicable building codes and regulations (provided that Landlord shall have the
right to withhold final payment until Tenant has furnished Landlord with the
items required in subsections 27.B.4.a. through 27.B.4.f.).

    28.     Intentionally Omitted.

    29.     Intentionally Omitted.

                                       24
<PAGE>

  30. Signage.

  I.  Elevator Lobby Sign.

     A. Tenant may, at its expense, install up to three (3) signs ("Lobby
Signs") identifying Tenant (Tenant name and logo), in the elevator lobby of the
elevator bank serving the Premises in the lobby at the Plaza level of the
Building (the "Low Rise Elevator Lobby") on the east and west walls at the north
end of such Low Rise Elevator Lobby, and on the east wall at the south end of
such Low Rise Elevator Lobby shown as point A, Point B and Point C,
respectively, on attached Exhibit "I", but only if:

     1. Tenant is not in default under this Lease at the time of installation
(or if in default, applicable grace periods have not then expired); and

     2. at the time of installation Tenant and/or Members of Tenant occupy (and
are legally entitled to occupy) or have leased at least 50,000 square feet of
space in the Building; provided, however, Tenant shall not be entitled to
install its Lobby Sign prior to the Commencement Date.

     B. Landlord, Landlord's architect and Tenant shall work together to
determine the general design (including, without limitation, the size, material,
shape and lettering) of the Lobby Signs, provided that Landlord's architect
shall have the right to make the final determination of the general design if
Landlord and Tenant cannot agree upon the general design. The precise location
and method of installation of each Lobby Sign must be approved by the architect
of Landlord in its reasonable discretion.

     C. The Lobby Signs may not be installed until the earlier to occur of (i)
June 30, 1988; and (ii) the date on which a sign identifying another tenant in
the Building is installed in the lobby at the Plaza level of the Building.

     D. All other elevator lobby signs at the Plaza level of the Building shall
have the same general appearance (i.e., size, material, shape and lettering
[except to the extent that a tenant's logo requires a certain type of
lettering]) as the Lobby Signs and shall be installed only at those locations
designated on Exhibit "I". There shall be no other signs in the lobby at the
Plaza level other than temporary signs which are in place for no more than one
hundred twenty (120) days, the lobby directory, and signband identifying the
retail tenants.

     E. No signs other than the Lobby Signs shall, be installed in the Low Rise
Elevator Lobby, provided that Landlord may install a sign for the parking garage
on the west wall at the south end of the Low Rise Elevator Lobby in the location
shown on Exhibit "I" attached hereto.

     F. Tenant, at its expense, shall repair and replace the Lobby Signs or
lettering when necessary. Landlord shall clean and maintain the Lobby Signs.

     G. Landlord may (at its option) remove the Lobby Signs, and the
restrictions on signage set forth in subsections 30.I.D. and 30.I.E. shall no
longer be effective or applicable, if at any time Tenant and/or Members of
Tenant occupy (and are legally entitled to occupy) or have leased less than
50,000 square feet in the Building (whether by reason of subleases, assignments
or otherwise); provided

                                       25
<PAGE>

that for purposes of this subsection 30.I.G., Tenant and/or its Members will be
deemed not to be in occupancy of any space in the Building which they are not
entitled to occupy (for example, if Tenant and/or its Members are in occupancy
as holdover tenants).

  II.  Building Sign.

     A. If:

          1. Landlord decides, in its sole discretion, to install a sign on or
outside of the Building identifying the Building and/or tenants of the Building
("Building Sign"), other than a signband identifying retail tenants; and

          2. Tenant is not in default under this Lease (or if in default,
applicable grace periods have not then expired) at the time of installation; and

          3. at the time of installation, Tenant and/or Members of Tenant occupy
(and are legally entitled to occupy) or have leased at least 75,000 square feet
of space in the Building;

Landlord shall include the name of Tenant on the Building Sign, it being
understood that the names of up to six (6) other tenants of the Building may be
listed on the Building Sign along with the name of Tenant.

     B. The Building Sign will be located at a point within the area and
substantially in the form shown on pages 1 and 2, respectively, of Exhibit "J"
attached hereto. The final design details, the exact location within the area
and the method of installation of such Building Sign shall be determined by
Landlord and the architect of Landlord in their sole and absolute discretion.

     C. If the Building Sign is installed, Landlord, at any time, in its sole
discretion, may delete the names of other tenants listed on the Building Sign.
Landlord shall not install more than one (1) Building Sign.

     D. If Landlord decides, in its sole discretion, to install the Building
Sign, Tenant shall pay its share of all of the costs of designing, constructing
and installing such sign, which share shall be determined as follows: Tenant
shall pay an amount ("Signage Share") equal to the total costs of the Building
Sign divided by the number of tenants whose names will appear on the sign when
it is initially installed. Tenant shall pay Landlord such amount within thirty
(30) days after receipt of an invoice therefore from Landlord. With respect to
each additional tenant whose name is added to the sign after its initial
installation, Landlord shall recalculate Tenant's Signage Share based upon the
increased number of tenants whose names will appear on the Sign, and if Tenant
is not in default under this Lease, Landlord shall remit the difference between
the Tenant's initial Signage Share and the Tenant's new Signage Share to the
Tenant (if the new Signage Share is less than the initial Signage Share).
Landlord shall remit any such amount within thirty (30) days after the addition
of the new name on the Building Sign.

                                       26
<PAGE>

     E. Landlord may, at its option, remove the Tenant's name from the Building
Sign, and may redesign or add new Building Signs without incorporating Tenant's
name thereon, if at any time the Tenant and/or Members of Tenant occupy (and are
legally entitled to occupy) or have leased less than 75,000 square feet in the
Building (whether by reason of subleases, assignments or otherwise); provided
that for purposes of this subsection 30.II.E., Tenant and/or its Members will be
deemed not to be in occupancy of any space in the Building which they are not
entitled to occupy (for example, if Tenant and/or its Members are in occupancy
as holdover tenants).

  31.  Antenna Option.

     A. Tenant may lease space on the roof of the Building ("Antenna Option") to
install, operate and maintain, at the expense of Tenant, a microwave receiving
and/or transmitting facility or other similar communications equipment
("Facility"), if:

          1. Landlord receives notice of exercise ("Antenna Notice") of this
Antenna Option at any time on or before eighteen (18) months prior to the
Expiration Date; and

          2. Tenant is not in default under this Lease, after any applicable
grace periods have expired, at the time it delivers the Antenna Notice;
provided, that if Tenant fails to cure any default existing at the time the
Antenna Notice is given within the applicable grace periods, Landlord, at its
option, may declare Tenant's Antenna Notice to be null and void; and

          3. the Antenna Area (defined below) is for the use of Tenant only
during the Term and thereafter, if Tenant continues to lease the Antenna Area
after the Term pursuant to subsection 31.D.; and

          4. Tenant obtains, at its expense, all necessary permits and licenses
form the City of Chicago and any other governmental agency having jurisdiction
prior to installing the Facility in the Antenna Area; and

          5. Tenant obtains the written approval of Landlord of the method of
installation of, and the plans and specifications for, the Facility prior to
installing the Facility prior to installing the Facility in the Antenna Area,
which approval shall not be unreasonably withheld; and

          6. Tenant executes and returns the "Antenna Supplement" (subsection
31.B.2. below) within thirty (30) days of its submission to Tenant.

     B. If Tenant is able to and properly exercises its Antenna Option:

          1. Landlord shall deliver seventy-five (75) square feet in a location
on the roof of the Building selected by Landlord; provided, however, if Tenant
determines the location selected by Landlord is not suitable, upon written
request from Tenant, Landlord will identify the areas on the roof of the
Building which Landlord has designated for use by tenants for communication
equipment and which are available to be leased by Tenant for its Facility, and
Tenant shall (subject to subsection 31.E.[ii] below) have the right to select an
alternate location within the

                                       27
<PAGE>

available areas on the roof of the Building, which in Tenant's judgment is more
suitable for placement of the Facility; provided further, however, any area on
the roof of the Building that is subject to the rights of other tenants in the
Building or in the 30 South Wacker Building (regardless of whether such rights
arise pursuant to a lease or lease amendment entered into subsequent to the date
hereof but prior to Tenant's selection of such alternate location) shall not be
available for lease by Tenant. The space ultimately designated for the Facility
shall be referred to herein as the "Antenna Area". Landlord makes no
representation and shall have no obligation with respect to the suitability of
the Antenna Area for use of the Facility.

          2. a. Landlord shall prepare an Antenna Supplement to this Lease to
reflect monthly installment for the Antenna Area, the annual increase in such
installment specified in subsection 31.C., the provisions of subsections 31.D.,
31.E., 31.F. and 31.G. and other appropriate terms set forth in this Section 31;
and

          b. a copy of the Antenna Supplement shall be sent to Tenant within a
reasonable time after receipt of the Antenna Notice and executed by Tenant and
returned to Landlord in accordance with subsection 31.A.6.;

          3. The term for the Antenna Area shall commence upon the stated
commencement date of the Antenna Supplement ("Antenna Commencement Date") and
all terms and conditions of this Lease shall be applicable to the Antenna Area
except Sections 3,4,27,33 and 35, and except to the extent that such terms and
conditions with the provisions of this Section 31 ( which provisions shall
govern and control the leasing of the Antenna Area).

     C. The monthly installment for the Antenna Area ("Antenna Installment")
shall be $500.00 for the first twelve (12) months subsequent to the Antenna
Commencement Date. The Antenna Installment shall then be increased at each
Antenna Space Anniversary ("Antenna Space Anniversary" means the annual
recurrence of the Antenna Commencement Date) by an amount equal to two percent
(2%) of the Antenna Installment due for the month immediately preceding such
Antenna Space Anniversary, e.g., if the Antenna Commencement date is February 1,
1989, then the Antenna Installment due for each month in the period commencing
February 1, 1989 and ending January 31, 1990 shall be $500.00, and the Antenna
Installment due for each month in the period commencing February 1, 1990 and
ending January 31, 1991 shall be $510.00, and the Antenna Installment due for
each month in the period commencing February 1, 1991 and ending January 31, 1992
shall be $520.00 and so on during the Term.

     D. The term of the Antenna Supplement shall end ("Antenna Expiration Date")
upon the Expiration Date or earlier termination of this Lease, provided that
Tenant may continue to lease the Antenna Area after the Antenna Expiration Date,
provided that Tenant:

          1. continues to occupy (and is entitled to occupy) and conduct
business on the Trading Floors (subsection 3.A.18) and/or continues to occupy
(and is entitled to occupy) and conduct business in office space in the
Building; and

                                       28
<PAGE>

          2. executes a lease for the Antenna Area ("Antenna Lease"),

               a. The term of the Antenna Lease shall commence on the day
immediately following the Antenna Expiration Date and end, with the exception
that Tenant shall have a right to cancel upon thirty (30) days prior notice, on
the later to occur of (i) the date Tenant no longer occupies (or is no longer
entitled to occupy) and conducts business on the Trading Floors, and (ii) the
date Tenant no longer occupies (or is no longer entitled to occupy) and conducts
business in office space in the Building.

               b. The initial Antenna Installment for the Antenna Area under the
Antenna Lease shall equal the Antenna Installment for the month in which the
Antenna Expiration Date occurred plus two percent (2%) of such Antenna
Installment, if the Antenna Lease commences on the original Antenna Space
Anniversary. The Antenna Installment shall thereafter continue to be increased
on the original Antenna Space Anniversary pursuant to subsection 31.C.

               c. So long as and to the extent that there will be Members
leasing in the aggregate of 100,000 square feet of space in the Building after a
fire or casualty, Tenant and Landlord shall have the same rights and obligations
under the Antenna Supplement with respect to the Antenna Area as is set forth in
Section II of this Lease with respect to the Premises.

               d. Tenant and Landlord shall have the same rights and obligations
under the Antenna Supplement with respect to the Antenna Area as is set forth in
Section 16 of this Lease with respect to the Premises.

               e. Tenant shall have the right to record a short form memorandum
of the Antenna Supplement on a form acceptable to Landlord and Tenant.

               f. Except as otherwise provided in this subsection 31.D.2., the
Antenna Lease shall be on the same terms and conditions as set forth in this
subsection 31.

     E. Tenant agrees that (i) it will cooperate with the owners and users of
other communications equipment installed in or on the Building, and (ii) the
installation and operation of the Facility will not interfere with the operation
or functioning of other communications equipment installed in or on the Building
prior to the installation of the Facility, and (iii) Tenant shall not alter,
redirect or change the method of operation of its Facility if such alteration,
redirection or change would interfere with the operation or functioning of other
communications equipment in or on the Building at the time of such alteration,
redirection or change, and (iv) if any interference of the type described in
clause (ii) or clause (iii) of this subsection 31.E.. occurs, Tenant will
eliminate the cause thereof at Tenant's expense..

     F. Tenant hereby agrees to indemnify and hold Landlord, its beneficiaries,
Owner and partners of Owner and their respective agents and employees harmless
against all claims, demands, liabilities, costs and expenses of any and every
kind, including, without limitation, reasonable attorney's fees, arising from or
connected in any way with the installation, use, operation or maintenance of the

                                       29
<PAGE>

Facility, including, without limitation, claims for interference prohibited by
subsection 31.E. or claims from third parties occupying other property.

     G. Tenant shall remove the Facility and repair all damage caused by such
removal, and restore the Antenna Area to the condition in which it existed
immediately prior to the time the Facility was installed, on the later to occur
of:

          1. the Antenna Expiration Date; and

          2. the expiration or earlier termination of the Antenna Lease (if such
Antenna Lease is entered into by Landlord and Tenant).

  32.  Intentionally Omitted

  33.  Obligation of Landlord to Repair and Maintain.

     Landlord shall, at its expense (except as otherwise provided herein through
inclusion in Expenses to the extent provided in subsection 3.a.4.), keep and
maintain in good repair and working order and make all repairs to and perform
necessary maintenance upon:

     A. the Building; and

     B. all structural elements of the Building within the Premises and the
Support Space (defined in the Support Space Supplement to this Lease); and

     C. all Systems within the Premises and the Support Space (defined in the
Support Space Supplement to this Lease), but only to the extent such have been
installed by Landlord or its contractors; and

     D. all elements of the Building and the Premises necessary to provide the
services described in Section 4, but only to the extent such have been installed
by Landlord or its contractors; and

     E. the Building facilities common to all tenants including, but not limited
to, the ceilings, lights, HVAC, plumbing, walls and floors in the common areas
(which common areas do not include the Lobby Space [defined in the Support Space
Supplement] leased by Tenant).

  34.  Secured Area(s).

     A. Notwithstanding subsection 7.I., Tenant may, if Tenant complies with
subsection 34.B below, provide its own locks to an area(s) within the Premises
("Secured Area(s)") at any time during the Term. Tenant need not furnish
Landlord with a key, but upon the Expiration Date, Tenant shall surrender all
such keys to Landlord. If Landlord determines in its sole discretion, that an
emergency (or other situation ) in the Building or the Premises, including,
without limitation, a suspected fire or flood, requires Landlord to gain access
to the Premises, Tenant hereby authorizes Landlord to forcibly enter the Secured
Area(s). In such event, except s provided in subsection 15. D., Landlord shall
have no liability whatsoever to Tenant, and Tenant shall pay all reasonable
expenses incurred by Landlord in repairing or reconstructing any entrance,
corridor or other door or other portions of the

                                       30
<PAGE>

Premises or the Secure Area(s) damaged as a result of the forcible entry by
Landlord. Landlord shall make reasonable efforts to contact Tenant or its
representatives to secure access to the Secured Area(s) prior to a forcible
entry but under no circumstances is Landlord obligated to contact Tenant.
Landlord shall have no obligation to provide either janitor service or cleaning
in the Secured Area(s).

     B. On or before ten (10) days prior to the date that Tenant establishes a
Secured Area by providing its own locks to such area, Tenant shall notify
Landlord of the location of the Secured Area and Tenant shall provide Landlord
with the name of the representatives of Tenants to be contacted and the manner
of contact to avoid a forcible entry as stated in subsection 34.A. above.

  35.  Parking

     A. Landlord shall, subject to the provisions of subsection 35.D. below,
during the Term, cause the operator ("Operator") of the Building automobile
parking facility to make thirty-seven (37) parking privileges ("Privileges")
available to Tenant.

     B. If, at any time during the Term, Tenant adds office space in the
Building to the initial Premises, Landlord shall subject to the provisions of
subsection 35.D. below, cause the Operator to make one (1) additional Privilege
available to Tenant for each 6,000 square feet added to the initial Premises.

     C. Tenant shall:

          1. contract with the Operator for the initial Privileges or any
subsequent Privileges made available by virtue of Tenant adding office space in
the Building to the initial Premises, within thirty (30) days after its
occupancy of the Premises or such additional space (as the case may be); and

          2. pay the monthly charge for the Privileges at the rate charges by
the Operator from time to time;

          3. use the Privileges so contracted for on a continuous basis.

     D. If Tenant fails to pay the aforesaid monthly charge, or to contract
within the time stated, or to continuously use the Privileges, Landlord need no
longer cause such Privileges which are not contracted for or used continuously
to be made available.

  36.  Insurance of Landlord

     A. Landlord shall maintain the following insurances coverages in full force
and effect during the Term, including insurance on the Building against fire or
casualty in amounts adequate to prevent co-insurance:

          1. standard so-called "all-risk" property insurance, covering the
Building in amounts at least equal to ninety percent (90%) of the replacement
cost of the building (including Tenant's improvements) at the time in question ,
but in no event less than such coverage as is required to avoid co-insurance
provisions;

                                       31
<PAGE>

          2. commercial general liability insurance (including contractual
liability) with minimum limits of $1,000,000.,, for injury to or death of one or
more persons and damage to or destruction of property in any occurrence
combined;

          3. excess liability insurance over the insurance required by
subsection 36.A.2. with minimum coverage of $19,000,000.00; and

          4. boiler and machinery coverage in amounts customarily carried by
landlords for other first-class office buildings located in Chicago.

     B. At the request of Tenant, Landlord shall furnish Tenant a certificate or
certificates of insurance showing that the insurance coverage required hereby is
in force. Any insurance required by the terms of this Lease to be carried by
Landlord may be under a blanket policy (or policies) covering other properties
of Landlord and/or its related or affiliated entities. If such insurance is
maintained under a blanket policy, Landlord procure and deliver to Tenant a
statement from the insurer or general agent of the insurer setting forth the
coverage maintained and the amounts thereof allocated to the risks intended to
be insured hereunder. All insurance required to be obtained and maintained by
Landlord pursuant to this Section shall be issued by responsible insuring
companies qualified to do business within the State of Illinois, and having
"Bests" Financial "Size Category Rating" of at least "A + XII" (or if a Bests"
rating is not then available, having a comparable rating by a similar
institution with offices located in a least five (5) cities within the United
States).

  37.  Vault

     A. Notwithstanding subsection 7.M., Landlord hereby grants Tenant
permission to install, at its own expense, a concrete and /or steel vault
("Vault") in the Premises provided however:

          1. such installation is performed in accordance with the terms of this
Lease; and

          2. on or before the Expiration Date, or earlier termination of this
Lease, Tenant shall, at its own expense, remove the Vault from the Premises and
restore the area where the Vault was installed to the condition in which it
existed before such installation, reasonable wear and tear expected.

     B. Tenant may, on or before sixty (60) days prior to the Expiration Date,
request permission to leave the Vault in the Premises with the understanding
that Landlord, in the exercise of its sole and absolute discretion, may refuse
such permission.

  38.  Access to Trading Floors.

     A. Tenant shall have the right to perform Alterations so as to provide
access to the Trading Floors (the "Access Alterations"). Such Access Alterations
shall be performed in accordance with the terms and conditions of this Lease,
including, but not limited to Section 9 hereof. Tenant shall perform such Access
Alterations at its sole cost and expense, provided the Tenant shall have the
right

                                       32
<PAGE>

to perform the Access Alterations as Initial Alterations (defined in the Work
Supplement attached hereto as Exhibit "C") and apply any portion of the Work
Credit that it is entitled to receive pursuant to subsection 27.B. hereof
against the cost of such Access Alterations.

     B. Notwithstanding anything to the contrary in subsection 9.K. hereof or
elsewhere in this Lease, Tenant shall be responsible for removing Access
Alterations and restoring those portions of the Premises affected by such
removal, including the restoration of any demising walls removed in connection
with the performance of Access Alterations, on or before the expiration Date or
earlier termination of this Lease. If Tenant has not restored the Premises by
such date, Landlord shall have the right to perform such restoration at Tenant's
sole cost and expense.

  39.  Non-Disturbance and Attornment Agreement

     As a condition precedent to Tenant's obligations hereunder, Landlord shall,
after receiving this Lease executed by Tenant, obtain and deliver to Tenant a
Non-Disturbance and Attornment Agreement ("Agreement") from Citicorp Real
Estate, Inc. ("Mortgagee"), in substantially the form of Exhibit "F" attached
hereto. Tenant shall execute the Agreement and submit it to Landlord at the same
time this Lease is executed and submitted to Landlord.

  40.  Quiet Enjoyment

     Notwithstanding any provisions contained in this Lease to the contrary,
Landlord covenants and agrees with Tenant that upon Tenant paying Base Rent,
Rent Adjustments and Rent Adjustment Deposits and observing and performing all
terms, covenants and conditions on the part of Tenant to be observed and
performed, Tenant shall have the right to peaceably and quietly enjoy the
Premises, subject nevertheless, to the terms and conditions of this Lease
including, but not limited to, Section 16 and Exhibit "F".

  41.  Intentionally Omitted.

  42.  Compliance With Laws.

     Tenant shall operate the Premises and Landlord shall operate the Building
in compliance with all applicable federal, state and municipal laws, ordinances
and regulations, unless such obligation is specifically imposed upon the other
party pursuant to the terms of this Lease, and shall not knowingly, directly, or
indirectly make any use of the Premises or the Building which I prohibited by
any such laws, ordinances, or regulations.

  43.  Security Services

     A. Tenant may contract with a fully licensed, insured and bonded security
company (the "Security Company") or, at Tenant's option, utilize an employee of
Tenant, in order to provide one unarmed security guard ("Security Guard") at the
main reception desk in the lobby on the Plaza Level of the Building for purposes
of monitoring only Tenant's employees, invitees, permitees and licensees who
wish entry into the Premises, or any portions thereof.

                                       33
<PAGE>

          1. Tenant agrees to hold harmless, indemnify and defend the Landlord
Related Parties from and against any and all claims, demands, liabilities, costs
and expenses (including, without limitation, reasonable attorney's fees) arising
from or connected in any way with (i) the acts or omissions of the Security
Guard (whether said Security Guard acts within or outside of his scope of
employment) or Security Company or (ii) the failure of Tenant to comply with
this Section 43; and

          2. Tenant shall bear the expense of (i) the service provided by the
Security Guard, (ii) changes to the main reception desk in the lobby on the
Plaza level, if changes are necessary to accommodate the Security Guard, and
(iii) and telecommunications system which Tenant may require at such main
reception desk; provided, however, that any changes to the main reception desk
(except for the installation of a telecommunications system) shall be subject to
the approval of Landlord (which Landlord may grant or withhold in its sole
discretion) and shall otherwise be performed in accordance with Section 9 of
this Lease; and

          3. If Tenant elects to use one of its employees as a Security Guard,
such Security Guard will be fully bonded and insured and, if required by any
applicable law, licensed.

     B. Services provided by the Security Guard shall at no time interfere with
the entrance reception service provided by Landlord in the Building (subsection
4.A.6.). Such services shall be performed in a manner consistent with similar
services in first-class downtown Chicago high-rise office buildings, and if
Landlord determines, in its reasonable judgment, that the Security Guard is not
performing in such a manner and so notifies Tenant, Tenant shall remove the
Security Guard, provided that Tenant shall have the right to substitute a new
Security Guard if Tenant complies with all the requirements of this Section 43.
The Security Guard shall not monitor or otherwise interfere with traffic to and
from the portions of the Building other than the Premises.

  44.  Renewal Option

     A. Tenant shall have the option to extend the Term for ten (10) years by
changing the Expiration Date from November 30, 2003 to November 30, 2013, if:

          1. Landlord receives notice of exercise ("Renewal Notice") on or
before December 1, 2002; and

          2. Tenant is not in default under this Lease, after any applicable
grace periods have expired, at the time of Landlord's receipt of the Renewal
Notice provided, that if Tenant fails to cure any default existing at the time
the Renewal Notice is given within the applicable grace periods, Landlord, at
its option, may declare Tenant's Renewal Notice (pursuant to subsection 44.A.1.)
to be null and void; and

          3. not more than twenty-five percent (25%) of the Premises (excluding
any subletting of the portion of the Premises located on the 10th floor of the
Building) is sublet to parties other than Members at the time of Landlord's
receipt of the Renewal Notice; and

                                       34
<PAGE>

          4. this Lease has not been assigned, with the exception of an
assignment to a Successor as defined in subsection 14.A.1., at the time of
Landlord's receipt of the Renewal Notice; and

          5. subject to Section 14 of this Lease (including Tenant's right to
sublet pursuant to Section 14), the Premises are intended to be for the use of
Tenant only during the entire Extension.

     B. The annual rate per square foot of Base Rent during the period
commencing on December 1, 2003 and ending on November 30, 2013 (the "Extension")
shall equal prevailing market. For the purpose of this Section 44 only,
"prevailing market" shall be determined by considering leases for "as-is" space
("As-Is Leases") being entered into at such time in the Building of the 30 South
Wacker Building giving appropriate consideration to rate per square foot,
escalation and abatement provisions, if any, length of lease term, size and
location of premises being leased, work or allowances, if any and other
applicable terms and conditions of tenancy; provided however, there shall be
excluded from a consideration of prevailing market, As-Is Leases entered into
under "special circumstances" which include the following (among others):

          1. the landlord being forced to lease space; or

          2. the lease term being less than five (5) years; or

          3. the space being subject to options or rights exercisable in the
future; or

          4. the space being of an awkward or unusual shape; or

          5. the lack of windows in the space.

If no As-Is Leases are than being entered into in the Building or the 30 South
Wacker Building, the same process stated in the preceding sentence shall be
used, but As-Is Leases in reasonably similar neighboring first class high rise
office buildings shall be the ones considered.

     C. If Tenant satisfies the conditions set forth in subsection 44.A. above,
Landlord shall prepare a Renewal Amendment reflecting the change in the
Expiration Date and any other appropriate terms. Execution counterparts of such
Renewal Amendment shall be delivered to Tenant for execution within a reasonable
time after Landlord's receipt of Renewal Notice. Tenant shall execute the
Renewal Amendment within thirty (30) days after its submission to Tenant. Upon
receipt of executed counterparts form Tenant, Landlord will execute and return,
as soon as practicable, one counterpart of the Renewal Amendment to Tenant.

  45.  Printing Facility.

     Landlord acknowledges that Tenant may request permission to install a
printing facility at some time during the Term to provide service to Tenant and
the Members only. Landlord hereby represents that in the event that Landlord
receives such a request, that it will not reject such request solely on the
basis that a printing facility would be beyond the Use set forth in Section 1 of
this Lease. Landlord

                                       35
<PAGE>

may, however, reject such request on the basis of Section 9 or any other
controlling provision of this Lease.

  46.  Escalator Option

     A. Tenant intends to install two (2) pairs of escalators (the "Escalators")
in the Premises as part of Initial Alterations (defined in the Work Supplement
attached hereto as Exhibit "C"). The first pair of escalators shall run up and
down between the third floor of the Premises through the fifth floor of the
Premises. The second pair of escalators shall run up and down between the fifth
floor of the Premises through the seventh of the Premises. Tenant shall be
responsible for the maintenance and repair of the Escalators during the Term.

     B. Tenant shall have the right to lease 23,144 square feet of space (the
"Escalator Areas") shown cross-hatched on the attached Exhibits K-1 (3rd floor),
K-2 (4th floor), K-3 (5th floor), K-4 (6th floor), and K-5 (7th floor) for an
initial term (the "Initial Escalator Term") of five (5) years commencing on the
day following the Expiration Date of this Lease, provided that:

          1. Tenant provides Landlord with written notice ("Escalator Notice")
by no later than one (1) year prior to the Expiration Date of this Lease;

          2. Tenant, after any applicable grace periods have expired, is not in
default under this Lease at the time Landlord receives Tenant's Escalator
Notice, provided that if Tenant fails to cure any default existing at the time
Tenant's Escalator Notice is given within the applicable grace periods,
Landlord, at its option, may declare Tenant's Escalator Notice (pursuant to
subsection 46.B.1.) to be null and void; and

          3. Tenant executes a lease for the Escalator Areas (the "Escalator
Lease") upon the terms and conditions set forth in subsection 46.D. below.

     C. Notwithstanding anything in subsection 46.B. or subsection 46.D. to the
contrary, Landlord shall have the right to reconfigure the Escalator Areas at
any time during the term of the Escalator Lease to provide for the construction
of any corridors required by the Chicago building code or any other applicable
codes, ordinances, rules or regulations and the cost thereof shall be borne in
accordance with the terms of this Lease. In addition, Landlord shall have the
right to reconfigure the Escalator Areas at any time prior to the commencement
of the Escalator Lease, provided that:

          1. Landlord will provide Tenant with written notice of its election to
reconfigure the Escalator Area (which notice shall contain demising plans
illustrating the new configuration) by no later than ninety (90) days after
receipt of Tenant's notice in accordance with subsection 46.B.1. above;

          2. Such reconfiguration may reduce, but not exceed, the square footage
of the Escalator Areas stated in subsection 46.B. above;

          3. Such reconfiguration will not materially affects Tenant's ability
to use the Escalator; and

                                       36
<PAGE>

          4. If the square footage of the Escalator Areas id reduced, the CPI
amount set forth in subsection 46.D.2.b. below and other appropriate terms shall
be appropriately adjusted on the basis of the new square footage of the
escalator areas.

     D. If Tenant is able to and properly exercise its right to lease the
Escalator Areas, Landlord shall prepare the Escalator Lease on the basis of the
following:

          1. the Initial Escalator Term shall be for five (5) years commencing
on the day following the Expiration Date of this Lease. Tenant shall have the
perpetual right to renew the Escalator Lease for successive terms of five (5)
years each (each renewal term shall be referred to herein as an "Escalator
Renewal Term"), provided that:

               a. Tenant provides Landlord with written notice to renew by no
later than one (1) year prior to the expiration date of the Initial Escalator
Term or applicable Escalator Renewal Term, as the case may be; and

               b. Tenant, after any applicable grace periods have expired, is
not in default under the Escalator Lease at the time Landlord receives Tenant's
notice to renew; provided, that if Tenant fails to cure any default existing at
the time Tenant's notice to renew is given within the applicable grace periods,
Landlord, at its option, may declare Tenant's Escalator Notice to be null and
void.

          2. The base rent and rent adjustments for the Escalator Areas during
the Initial Escalator Term and subsequent Escalator Renewal Terms shall be:

               a. an annual base rent of $17.45 per square foot ;

               b. a CPI (as defined in this Lease) amount for each Lease Year of
$162,008 ($7.00 X 23,144) multiplied by the percentage of increase by which the
CPI for April of any lease year (including, without limitation the first year
Escalator lease year) of the Escalator Lease during the Initial Escalator Term
of subsequent Escalator Renewal Terms exceeds the CPI for the Escalator Base
Year (defined below);

               c. an amount equal to Tenant's Escalator Area Proportion (defined
below) of Expenses during the Initial Escalator Term or subsequent Escalator
Renewal Terms;

               d. an amount equal to Tenant's Escalator Area Protection (defined
below) of Taxes during the Initial Escalator Term or subsequent Escalator
Renewal Terms.

          3. Tenant and Landlord shall have the same rights and obligations
under the Escalator Lease with respect to the Escalator Areas as is set forth in
Section 11 of this Lease with respect to the Premises;

          4. Landlord shall use reasonable efforts to provide Tenant with the
same rights and obligations under the Escalator Lease with respect to the
Escalator Areas as is set forth in Section 16 and Section 39 of this Lease with
respect to the Premises;

                                       37
<PAGE>

          5. Tenant shall have the right to record a short form memorandum of
the Escalator Lease on a form acceptable to Landlord and Tenant;

          6. Tenant shall be solely responsible for the repair and maintenance
of the Escalators and for the removal of the Escalators in accordance with
subsection 46.F. below.

          7. Tenant shall, at its sole cost and expense, be responsible for
erecting demising walls and ceilings, constructed with soundproofing materials
such as fiberglass, additional layer(s) of gypsum board and duct transfer and
otherwise preparing the Escalator Areas in accordance with Exhibits "K-1"
through "K-5", and

          8. Except as to any terms and conditions specifically provided herein,
Landlord shall prepare the Escalator Lease on the standard from lease being used
by Landlord at the expiration of this Lease, with such changes as Tenant may
reasonably request or as may be necessary to confirm with any provision hereof.

     E. Execution counterparts of the Escalator Lease shall be delivered to
Tenant for execution within a reasonable time after Landlord's receipt of
Tenant's initial notice of its intent to exercise its rights with respect to the
Escalators Areas. Landlord and Tenant shall proceed with due diligence to arrive
at a final negotiated version of the Escalator Lease specifically including the
terms set forth in subsection 46.D. hereof.

     F. Notwithstanding anything in subsection 9.K. hereof to the contrary, if
Tenant does not exercise its right to lease the Escalator Areas, Tenant shall,
upon the Expiration Date or earlier termination of this Lease, remove the
Escalators and restore the Premises to the condition that existed on the
execution of this Lease insofar as the Premises were altered to permit the
installation of the Escalators. Notwithstanding anything in subsection 9.K.
hereof to the contrary, if Tenant exercised its rights to lease the escalator
Areas, Tenant shall, prior to the expiration or earlier termination of the
Escalator Lease, remove the Escalators located in the Escalator Areas and
restore the Escalator Areas to the condition that existed at the execution of
this Lease insofar as the Premises were altered to permit installation to the
Escalators. If Tenant fails to remove the Escalators and restore the Premises or
the Escalator Areas, as the case may be, as provided herein, Landlord shall have
the right to perform such work at Tenant's sole cost and expense.

     G. For purposes of this Section 46:

          1. "Escalator Base Year" means the calendar month of April, 1988;

          2. "Escalator Area Proportion" means the percentage derived by
dividing the current rentable area of the Escalator Area by the Rentable Area of
the Building and multiplying by one hundred (100).

  47.  Telecommunication Closet Option

     A. Tenant shall have the right to lease the 70 usable square feet of space
(the "Telecommunication Closet Area") shown cross-hatched and designated as "CME

                                       38
<PAGE>

            Electrical Closet" on the attached Exhibits "L-1" (2nd floor), "L-2"
            (3rd floor), "L-3" (4th floor), "L-4" (5th floor), "L-5" (6th
            floor), "L-6" (7th floor), "L-7" (8th floor), "L-8" (9th floor),
            "L-9" (10th floor) and "L-10" (M-1 floor) for an initial tern of
            five (5) years commencing on the day following the Expiration Date
            of this Lease (the "Initial Telecommunication Closet Lease Term"),
            provided that:

          1. Tenant provides Landlord with written notice ("Telecommunication
Notice") by no later than one (1) year prior to the Expiration Date of this
Lease of its intention to lease the Telecommunication Closet Area;

          2. Tenant, after any applicable grace periods have expired, is not in
default under this Lease at the time Landlord receives Tenant's
Telecommunication Notice; provided that if Tenant fails to cure any default
existing at the time Tenant's Telecommunication Notice is given within the
applicable grace periods, Landlord, at its option, may declare Tenant's
Telecommunication Notice to be null and void.

          3. Tenant executes a lease for the Telecommunication Closet Areas (the
"Telecommunication Closet Lease") upon the terms and conditions set forth in
subsection 47.B. below.

     B. If Tenant is able to and properly exercise its rights to lease the
Telecommunication Closet Areas, Landlord shall prepare the Telecommunication
Closet Lease on the basis of the following:

          1. the Initial Telecommunication Closet Lease shall be for five (5)
years commencing on the day following the Expiration Date of this Lease. Tenant
shall have the perpetual right to renew the Telecommunication Closet Lease for
successive terms of five (5) years each (each renewal term shall be referred to
herein as an "Telecommunication Closet Renewal Term"), provided that:

               a. Tenant provides Landlord with written notice to renew by no
later than one (1) year prior to the expiration date of the Initial
Telecommunication Closet Lease Term or applicable Telecommunication Closet
Renewal Term, as the case may be; and

               b. Tenant, after any applicable grace periods have expired, is
not in default under the Telecommunication Closet Lease at the time Landlord
receives Tenants notice to renew; provided that if Tenant fails to cure any
default existing at the time Tenant's notice to renew is given within the
applicable grace periods, Landlord, at its option, may declare Tenant's notice
to renew (pursuant to subsection 47.B.1.a.) to be null and void.

          2. a. the annual base rent per square foot for the telecommunication
Closet Area during the first year of the Initial Telecommunication Closet Lease
Term shall equal the annual base rent per square foot contained in the Support
Installment in effect for the last month of the Support Term (defined in the
Support Space Supplement to this Lease multiplied by one hundred four percent
(104%); and

               b. subsequently, the annual base rent per square foot shall be
increased at each Telecommunication Anniversary (defined below) during the
Initial

                                       39
<PAGE>

Telecommunication Closet Lease Term and any applicable Telecommunication Closet
Renewal Term by an amount equal to four percent (4%) of the annual base rent per
square foot in effect immediately preceding such Telecommunication Anniversary;
and

               c. no Rent Adjustments shall be payable with respect to the
Telecommunication Closet Area.

          3. So long as to the extent that Tenant and/or Members will be leasing
in the aggregate of 100,000 square feet of space in the Building after a fire or
casualty who were hooked into and receiving service from Tenant's
telecommunication system prior to a fire or casualty, Tenant and Landlord shall
have the same rights and obligations under the Telecommunication Closet Lease
with respect to the Telecommunication Closet Area as is set forth in Section 11
of this Lease with respect to the Premises;

          4. Landlord shall use reasonable efforts to provide Tenant with the
same rights and obligations under the Telecommunication Closet Lease with
respect to the Telecommunication Closet Area as is set forth in Section 16 and
39 of this Lease with respect to the Premises.

          5. Tenant shall have the right to record a short form memorandum of
the Telecommunication Closet Lease on a form acceptable to Landlord and Tenant;

          6. Tenant shall use the freight elevators to obtain access to and from
the Telecommunication Closet Areas; and

          7. Except as to any terms and conditions specifically provided herein,
Landlord shall prepare the Telecommunication Closet Lease on the standard form
storage space lease being used by Landlord at the Expiration Date of this Lease,
with such changes as Tenant may reasonably request or as may be necessary to
conform with any provisions hereof.

     C. Execution counterparts of the Telecommunication Closet Lease shall be
delivered to Tenant for execution within a reasonable time after Landlord's
receipt of Tenant's initial notice of its intent to exercise its rights with
respect to the Telecommunication Closet Areas. Landlord and Tenant shall proceed
with due diligence to arrive at a final negotiated version of the
Telecommunication Closet Lease specifically including the terms set forth in
subsection 47.B. hereof.

     D. For purposes of this Section 47, "Telecommunications Anniversary" means
the annual recurrence of the month in which the Initial Telecommunications
Closet Term commences.

  48.  Expansion Option.

     A. Tenant may lease additional space ("Expansion Option"), if:

          1. Tenant, after any applicable grace periods have expired, is not in
default under this Lease; provided that if Tenant fails to cure any default
existing at the time Tenant's Five, Ten or Fifteen Year Notice, as the case may
be, is given

                                       40
<PAGE>

within the applicable grace periods, Landlord, at its option, may declare
Tenant's Five, Ten or Fifteen Year Notice, as the case may be, to be null and
void; and

          2. no more than fifteen percent (15%) of the Premises (excluding any
subletting of the portion of the Premises located on the 10th floor of the
Building) is sublet to parties other than Members at the time of Landlord's
receipt of the Five, Ten and/or Fifteen Year Notice (defined below), as the case
may be; and

          3. this Lease has not been assigned, except to a Successor; and

          4. the Five, Ten and/or Fifteen Year Space (defined below) is intended
to be for the exclusive use of Tenant or a Successor only, except as permitted
by subsections 14.C. and 14.D.; and

          5. for Fifteen Year Space only, Tenant has exercised or concurrently
exercises its Renewal Option (Section 44); and

          6. Landlord receives notice of exercise of this Expansion Option for:

               a. Five Year Space ("Five Year Notice") on or before March 31,
1992; and

               b. Ten Year Space ("Ten Year Notice") on or before March 31,
1997; and

               c. Fifteen Year Space ("Fifteen Year Notice") on or before
November 30, 2002; and

          7. Tenant executes and returns the Five, Ten or Fifteen Year
Amendment(s), as the case mat be, (subsection 48.D.1. below) within thirty (30)
days of their submission to Tenant.

     B. Landlord shall provide Tenant with Five Year Space, Ten Year Space and
Fifteen Year Space, as the case may be, in accordance with Tenant's priority
list to the extent possible, considering the availability of space in the
Building and in the 30 South Wacker Building. The Tenant's priority list is as
follows: first, on floors 11 through 17 inclusive, in the Building or on floors
2 through 22 inclusive, in the 30 South Wacker Building ("First Location");
secondly, on floors 23 through 30 in the 30 South Wacker Building ("Second
Location"); and thirdly, on floors 18 through 40 inclusive, in the Building or
on floors 31 through 40 inclusive, in the 30 South Wacker Building ("Third
Location") (such First, Second, and Third Location shall collectively be
referred to herein as the "Expansion Location").

     C. 1. If Tenant is able to and appropriately exercises its Expansion Option
for Five Year Space, Landlord shall designate one (1) full floor located within
the Expansion Location ("Five Year Space") on or before 180 days after March 31,
1992 and shall deliver such Five Year Space during the period commencing 90 days
after Landlord designates such Five Year Space and ending on April 1, 1994, but
in no event prior to January 1, 1993 ("Five Year Space Window")...

          2. If Tenant is able to and appropriately exercises its Expansion
Option for Ten Year Space, Landlord shall designate one (1) full floor located

                                       41
<PAGE>

within the Expansion Location ("Ten Year Space") on or before 180 days after
March 31, 1997 and shall deliver such Ten Year Space during the period
commencing 90 days after Landlord designates such Ten Year Space and ending on
July 1, 1999, but in no event prior to October 1, 1997 ("Ten Year Space
Window").

          3. If Tenant is able to and appropriately exercises its Expansion
Option for Fifteen Year Space, Landlord shall designate one (1) full floor
located within the Expansion Location ("Fifteen Year Space") on or before 180
days after November 30, 2002 and shall deliver such Fifteen Year Space during
the period commencing 90 days after Landlord designates such Fifteen Year Space
and ending on June 1, 2005, but in no event prior to June 1, 2003 ("Fifteen Year
Space Window").

     D. If Tenant is able to and appropriately exercises its Expansion Option
for Five, Ten, and/or Fifteen Year Space:

          1. Landlord shall prepare an amendment (the "Five, Ten or Fifteen Year
Amendment", as the case may be) to reflect changes in:

               a. the size of the Premises;

               b. Base Rent;

               c. Installments;

               d. Tenant's Proportion; and

               e. Other appropriate terms.

          2. A copy of the Five, Ten and/or Fifteen Year Amendment shall be:

               a. sent to Tenant within a reasonable time after receipt of the
Five, Ten and/or Fifteen Year Notice; and

               b. Executed by Tenant and returned to Landlord in accordance with
subsection 48.A.7.

     E. 1. The annual Base Rent rate per square foot for Five Year Space, Ten
Year Space and Fifteen Year Space, as the case may be, shall equal:

               a. $17.45 per square foot if such Five, Ten and Fifteen Year
Space, as the case may be, is in the First Location; or

               b. $20.00 per square foot if such Five, Ten and Fifteen Year
Space, as the case may be, is in the Second Location or the Third Location.

          2. Tenant shall pay Rent Adjustments for the Five, Ten and Fifteen
Year Space, as the case may be, on the same terms and conditions set forth in
Section 3 of this Lease, including, but not limited to the Base Year of April,
1988.

     F. 1. Landlord shall deliver Five Year Space to Tenant in no more than two
(2) separate blocks of Five Year Space. No part of any single block of Five

                                       42
<PAGE>

Year Space shall contain space that is not contiguous to the remainder of such
block. The first block of Five Year Space delivered by Landlord shall contain no
less than fifty percent (50%) of the total square footage of all Five Year Space
that Landlord is required to deliver pursuant to subsection 48.C.1. The second
block of Five Year Space shall contain the remainder of the floor in which the
initial block of Five Year Space is located. The term for each block of Five
Year Space shall commence on the date that such space is delivered to Tenant and
thereupon such space shall be considered Premises, subject to all terms and
conditions of this Lease.

          2. Landlord shall deliver Ten Year Space to Tenant in no more than two
(2) separate blocks of Ten Year Space. No part of ant single block of Ten Year
Space shall contain space that is not contiguous to the remainder of such block.
The first block of Ten Year Space delivered by Landlord shall contain no less
than fifty percent (50%) of the total square footage of all Ten Year Space that
Landlord is required to deliver pursuant to subsection 48.C.2. The second block
of Ten Year Space shall contain the remainder of the floor on which the initial
block of Ten Year Space is located. The term for each block of Ten Year Space
shall commence on the date that such space is delivered to Tenant and thereupon
such space shall be considered Premises, subject to all terms and conditions of
this Lease. 3. Landlord shall deliver Fifteen Year Space to Tenant in no more
than two (2) separate blocks of Fifteen Year Space. No part of any single block
of Fifteen Year Space shall contain space that is not contiguous to the
remainder of such block. The first block of Fifteen Year Space delivered by
Landlord shall contain no less than fifty percent (50%) of the total square
footage of all Fifteen Year Space that Landlord is required to deliver pursuant
to subsection 48.C.3. The second block of Fifteen Year Space shall contain the
remainder of the floor in which the initial block of Fifteen Year Space is
located. The term for each block of Fifteen Year Space shall commence on the
date that such space is delivered to Tenant and thereupon such space shall be
considered Premises, subject to all terms and conditions of this Lease.

     G. When Landlord has established the annual Base Rent rate per square foot
for the Five, Ten or Fifteen Year Space, as the case may be, such amount shall
be multiplied by the Rentable Area of the Five, Ten or Fifteen Year Space then
being added to the Premises, as the case may be, and the sum so derived shall be
divided by twelve (12) to obtain the Installments payable for the Five, Ten or
Fifteen Year Space being added, as the case may be. Such Installment shall then,
between the commencement of the term for Five, Ten or Fifteen Year Space, as the
case may be, and the Expiration Data, be added to total the Base Rent payable
for the balance of the Premises.

     H. The Five, Ten and Fifteen Year Space, as the case may be (including
improvements and personalty, if any, shall be accepted by Tenant in its
"as-built" condition and configuration as of the date the term for such space
commences, unless it has never been occupied, under which circumstances
Landlord, at Tenant's option, shall either:

          1. construct such space to building standard existing on the date that
such Five, Ten and Fifteen Year Space, as the case may be, is to be delivered

                                       43
<PAGE>

(provided that if there is no building standard on such date Landlord shall
construct such space to building standard as described in Exhibit "M"); or

          2. provide Tenant with a credit in the amount of the value of
applicable building standard describes in subsection 48.H.1. above

  49.  Intentionally Omitted.

  50.  Right of First Offering

     A. During the Term of this Lease, when Landlord has a prospective tenant
("Prospect") interested in leasing any space on floors 11 through 24 inclusive,
of the Building, Landlord shall advise Tenant in the manner set forth in Exhibit
"P" attached hereto ("Advice") of such interest to lease such space, and Tenant
may lease ("Right of First Offering" [ROFO]) the space shown in the Advice
("Offering Space"), in its entirety only, under the terms of the Advice, except
that Tenant shall have no right and Landlord need not give the Advice, if:

          1. Tenant is in default under this Lease after any applicable grace
period expired; provided that if Tenant fails to cure any default existing at
the time Tenant exercises its ROFO pursuant to the Advice ("Notice of Exercise")
within the applicable grace periods, Landlord, at its option, may declare
Tenant's Notice of Exercise to be null and void; or

          2. more than fifteen percent (15%) of the Premises (excluding any
subletting of the portion of the Premises located on the 10th floor of the
Building) is sublet to parties other than Members; or

          3. this Lease has been assigned, with the exception of an assignment
to a Successor, as defined in subsection 14.A.1.; or

          4. Tenant is not an occupant of the Building under this Lease; or

          5. subject to section 14 of this Lease (including Tenant's right to
sublet pursuant to Section 14), the Offering Space is not to be used by Tenant
for its own immediate use; or

          6. the Offering Space is subject to Superior Rights (defined below).

     B. Notwithstanding anything to the contrary in this Section 50, Tenant's
ROFO with respect to any Offering Space, shall be subject and subordinate to:

          1. the renewal rights of any tenant with respect to such Offering
Space (regardless of whether such rights arose pursuant to a lease or lease
amendment executed to the date hereof);

          2. an extension of the lease term by a tenant leasing such Offering
Space;

          3. the expansion rights of any tenant in the Building or the 30 South
Wacker Building with respect to such Offering Space (regardless of whether such

                                       44
<PAGE>

rights arose pursuant to a lease or lease amendment executed subsequent to the
date hereof); and

          4. the right of first offering rights of any tenant in the Building or
30 South Wacker Building existing as of the date hereof.

               The foregoing rights set forth in subsection 50.B.1. through
subsection 50.B.4. above, shall be referred to herein as "Superior Rights".

     C. 1. The ROFO shall be exercised by the execution by Tenant and delivery
to Landlord of:

                    a. the Notice of Exercise within fifteen (15) days after the
date of the Advice; and

                    b. the Offering Amendment (as defined in subsection 50.E.)
within thirty (30) days after the submission of the Offering Amendment to Tenant
by Landlord.

          2. All terms stated in the Advice (including, without limitation, the
expiration date set forth in the Advice) shall govern Tenant's lease of the
Offering Space, and only to the extent that they do not conflict with the
Advice, the terms and conditions of this Lease shall apply to the Offering
Space, except that no allowances, credits, abatements, rent caps or other rent
limitations contained in this Lease shall apply to the Offering Space.

     D. The term for the Offering Space shall commence upon the commencement
date as stated in the Offering Amendment, and the Offering Space shall thereupon
be considered a part of the Premises subject to all terms and conditions of this
Lease (except to the extent modifications are required pursuant to subsection
50.C.2.).

     E. If Tenant is able to and properly exercises its ROFO, Landlord shall
prepare an amendment (the "Offering Amendment") adding the Offering Space to the
Premises, and reflecting the terms and conditions stated in the Advice. A copy
of such Offering Amendment shall be:

          1. sent to Tenant within a reasonable time after receipt of the Notice
of Exercise in the Advice; and

          2. executed by Tenant and returned to Landlord in accordance with
subsection 50.C.1.b. above.

     F. The rights of Tenant under this Section 50 shall commence, subject to
Superior Rights, as to any particular Offering Space immediately after initial
leasing of such Offering Space and terminates as to:

          1. all Offering Space, one (1) year prior to the Expiration Date of
this Lease as the same may be extended pursuant to the Tenant's Renewal Option;
and

          2. any particular Offering Space, under any and all circumstances on
the earlier of:

                                       45
<PAGE>

                    a. the failure of Tenant to exercise the ROFO; or

                    b. the date upon which the rejection portion of the Advice
is executed by Tenant, provided that Landlord consummates such lease with such
Prospect at any time after such rejection (or with another prospective tenant
within six (6) months after such rejection) on substantially the same economic
terms as set forth in the Advice, i.e., no greater than 10 percent (10%)
reduction on an aggregate basis, in the base rent, rent credits or allowances,
construction allowances and other economic terms set forth in the Advice, and
with no more than a ten percent (10%) change in the rentable area of the
Offering Space.

Under such circumstances set forth in subsection 50.F.2.a (subject to Section 48
of this Lease, if the Offering Space is Five, Ten, or Fifteen Year Space, as the
case may be), Landlord shall be free to lease the Offering Space on any terms
and conditions it deems appropriate.

  51.  Bathroom Facilities.

     A. Tenant intends to install bathroom facilities (the "Facilities") on the
third and seventh floors of the Premises as part of Initial Alterations (defined
in the Work Supplement attached hereto as Exhibit "C"). Tenant shall pay
Landlord as additional rent any increase in the cost of providing janitorial
services to such floors over the cost that would have been incurred for
providing janitorial services absent the installation of the Facilities.

     B. Tenant shall have the right to lease 7,686 square feet of space (the
"Bathroom Facility Areas") shown cross-hatched on the attached Exhibit "Q-1"
(3rd floor) and "Q-2" (7th floor) for an initial term (the "Initial Bathroom
Facility Term") of five (5) years commencing on the day following the Expiration
Date of this Lease; provided that:

          1. Tenant provides Landlord with written notice (the "Bathroom
Facility Notice") by no later than one (1) year prior to the Expiration Date of
this Lease as the same may be extended pursuant to Tenant's Renewal Option;

          2. Tenant, after any applicable grace periods have expired, is not in
default under this Lease at the time Landlord receives Tenant's Bathroom
Facility Notice; provided that if Tenant fails to cure any default existing as
of the date the Bathroom Facility Notice is given within the applicable grace
periods, Landlord, at its option, may declare Tenant's Bathroom Facility Notice
(pursuant to subsection 51.B.1) to be null and void; and

          3. Tenant executes a lease for the Bathroom Facility Areas (the
"Bathroom Facility Lease") upon the terms and conditions set fourth in
subsection 51.C.
below.

     C. If Tenant is able to and properly exercises its rights to lease the
Bathroom Facility Areas, Landlord shall prepare the Bathroom Facility Lease on
the basis of the following:

                                       46
<PAGE>

          1. the Initial Bathroom Facility Term shall be for five (5) years
commencing on the day following the Expiration Date of this Lease, as the same
may be extended pursuant to Tenant's Renewal Option. Tenant shall have the
perpetual right to renew the Bathroom Facility Lease for successive terms of
five (5) years each (each renewal term shall be referred to herein as a
"Bathroom Facility Renewal Term"), provided that:

               a. Tenant provides Landlord with written notice to renew by no
later than one (1) year prior to the expiration date of the Initial Bathroom
Facility Term or applicable Bathroom Facility Renewal Term, as the case may be;
and

               b. Tenant, after any applicable grace periods have expired, is
not in default under the Bathroom Facility Lease at the time Landlord receives
Tenant's notice to renew; provided that if Tenant fails to cure any default
existing as of the date the notice is given within the applicable grace periods,
Landlord, at its option, may declare Tenant's notice to renew (pursuant to
subsection 51.C.1.a.) to be null and void.

          2. The base rent and rent adjustments for the Bathroom Facility Areas
during the Initial Bathroom Facility Term and subsequent Bathroom Facility
Renewal Terms shall be:

               a. an annual base rent rate of $17.45 per square foot;

               b. a CPI (as defined in this Lease) amount for each lease year of
$53,802.00 ($7.00 X 7,686) multiplied by the percentage of increase by which the
CPI for April of any lease year (including, without limitation for the first
lease year) of the Bathroom Facility Lease during the Initial Bathroom Facility
Term or subsequent Bathroom Facility Renewal Terms exceeds the CPI for the
Bathroom Facility Base Year (defined below); c. an amount equal to Tenant's
Bathroom Facility Areas Proportion (defined below) of Expenses during each lease
year of the Initial Bathroom Facility Term or subsequent Bathroom Facility
Renewal Terms;

               d. an amount equal to Tenant's Bathroom Facility Areas Proportion
(defined below) of Taxes during each lease year of the Initial Bathroom Facility
Term or subsequent Bathroom Facility Renewal Terms.

          3. Tenant and Landlord shall have the same rights and obligations
under the Bathroom Facility Lease with respect to the Bathroom Facility Areas as
is set forth in Section II of this Lease with respect to the Premises;

          4. Landlord shall use reasonable efforts to provide Tenant with the
same rights and obligations under the Bathroom Facility Lease with respect to
the Bathroom Facility Areas as is set forth in Section 16 and Section 39 of this
Lease with respect to the Premises;

          5. Tenant shall have the right to record a short form memorandum of
the Bathroom Facility Lease on a form acceptable to Landlord and Tenant;

          6. Tenant shall be solely responsible for the repair and maintenance

                                       47
<PAGE>

of the Bathroom Facility areas and for the removal of the Bathroom Facility
Areas in accordance with subsection 51.E. below.

          7.  Except as to any terms and conditions specifically provided
herein, Landlord shall prepare the Bathroom Facility Lease on the standard form
lease being used by Landlord at the Expiration Date of this Lease, with such
changes as Tenant may reasonably request or as may be necessary to conform with
any provision hereof.

    D. Execution counterparts of the Bathroom Facility Lease shall be delivered
to Tenant for execution within a reasonable time after Landlord's receipt of
Tenant's initial notice of its intent to exercise its rights with respect to the
Bathroom Facility Areas. Landlord and Tenant shall proceed with due diligence to
arrive at a final negotiated version of the Bathroom Facility Lease Specifically
including the terms set forth in subsection 51.C. hereof.

    E. Notwithstanding anything in subsection 9.K. hereof to the contrary, if
Tenant does not exercise its right to lease the Bathroom Facility Areas, Tenant
shall, upon the Expiration Date or earlier termination of this Lease, remove the
Facilities in the Bathroom Facility Areas and Tenant shall restore the Premises
to the condition that existed on the execution of this Lease insofar as the
Premises were altered to permit the installation of the Facilities in the
Bathroom Facility Areas. Notwithstanding anything in subsection 9.K. hereof to
the contrary, if Tenant exercised its rights to lease the Bathroom Facility
Areas, Tenant shall, prior to the Expiration Date or earlier termination of the
Bathroom Facility Lease, remove the facilities in the Bathroom Facility Areas
and restore the Bathroom Facility Areas to the condition that existed at the
execution of this Lease insofar as the Premises were altered to permit the
installation of the Facilities in the Bathroom Facility Areas. If Tenant fails
to remove the Facilities in the Bathroom Facility Areas and restore the Premises
or the Bathroom Facility Areas, as the case may be, as provided herein, Landlord
shall have the right to perform such work at Tenant's sole cost and expense.

    F. For the purpose of this Section 51:

         1. "Bathroom Facility Base Year" means the calendar month of April,
1988;

         2. "Bathroom Facility Areas Proportion" means the percentage derived by
dividing the then current rentable area of the bathroom Facility Areas by the
Rentable Area of the Building and multiplying by one hundred (100).

 52.   Elevators.

          Tenant acknowledges that the vertical transportation system of the
Building ("Elevators") is not designed to handle traffic to and from the Trading
Floor and Related Facilities thereto ("Related Facilities" defined as Member
coatrooms, mailrooms and such) or traffic in excess of that commonly associated
with general office use. Therefore, notwithstanding anything in subsection
4.A.3. hereof to the contrary, if by reason of such traffic the vertical
transportations system becomes overburdened, Tenant acknowledges that Landlord
will not be responsible for such overburdening.

                                      48

<PAGE>

  53.   Concurrent Exercise of Options.

     With respect to Tenant's options under Sections 46,47,51 and the Support
Space Supplement to lease the Escalator Areas, Telecommunications Areas, the
Bathroom Facilities, the Lobby Space, the M-1 Space and the UPS Space, such
options may be exercised in any combination and if the exercise of an option
with respect to one such space includes a portion of another such space, a
separate option exercise with respect to the included portion of such other
space shall not be necessary, and Base Rent and Rent Adjustments, if any, shall
not apply more than once (even if under more than one Section of the Lease) to
any such space.

  54.  Landlord's Execution of Documents.

     Any provision contained in this Lease and the Support Space Supplement
which requires Tenant to execute and return to Landlord any amendments,
supplements, leases or other than notices (collectively referred to in this
Section 54 only as "Documents") within a specified period of time, shall apply
with equal force to Landlord with regard to the execution by Landlord and return
to Tenant of the Documents after receipt by Landlord from Tenant. In the event
that Landlord fails to execute and return to Tenant any Documents within the
applicable time period, Tenant, at any time after such period but prior to its
receipt of the fully executed Documents from Landlord shall have the right to
revoke its delivery and withdraw its execution of such Documents by serving
Landlord with written notice thereof.

                                       49
<PAGE>

IN WITNESS WHEREOF, the parties hereto shall be deemed to have executed this
Lease on the date first above written.

                                                     LANDLORD

                                   AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                   CHICAGO, a national banking association of
                                   Chicago, Illinois, not individually but
                                   solely as Trustee under the provisions of a
                                   certain Trust Agreement dated June 2, 1981
                                   and known as Trust No. 51234.

ATTEST:

By /s/                              By /s/
   ------------------------------      ----------------------------
   Title Asst.                         Title Vice President
        -------------------------           -----------------------

ATTEST OR WITNESS:                                 TENANT
                                   CHICAGO MERCANTILE EXCHANGE, an Illinois
                                   not-for-profit corporation

By /s/                              By /s/
   ------------------------------      ----------------------------
   Title Sr. VP. Admin. & Finance      Title Chairman
        -------------------------           -----------------------

                                       50
<PAGE>

                                 FIRST AMENDMENT

         THIS FIRST AMENDMENT (the "Amendment") is made and entered into as of
NOV 01 1999, by and between EOP -10 & 30 SOUTH WACKER, L.L.C., a Delaware
limited liability company, as beneficiary of land trust dated October 1, 1997,
and known as American National Bank and Trust Company of Chicago Trust No.
123434-06 ("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois
not-for-profit corporation ("Tenant").

                                   WITNESSETH

A.   WHEREAS, Landlord (as successor in interest to American National Bank and
     Trust Company of Chicago, Illinois, a national banking association of
     Chicago, Illinois, not individually but solely as Trustee under the
     provisions of a certain Trust Agreement dated June 2, 1981, and known as
     Trusty No. 51234) and Tenant are parties to that certain lease dated the
     31st day of March, 1988 (the "Lease"), for space currently containing
     approximately 175,660 rentable square feet (the "Original Premises")
     described as being on the 2nd through 10th floors inclusive, in the
     building commonly known as 10 South Wacker Drive and the address of which
     is 10 South Wacker Drive, Chicago, Illinois (the "Building"); and

B.   WHEREAS, Tenant has requested that additional space containing
     approximately 8,242 rentable square feet on the 31st floor of the Building
     shown on Exhibit A hereto (identified below as Expansion Space I and
     Expansion Space II and collectively referred to herein as the "Expansion
     Space") be added to the Original Premises and that the Lease be
     appropriately amended and Landlord is willing to do the same on the terms
     and conditions hereinafter set forth;

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

         I.    Expansion and Effective Date. Effective as of Expansion Effective
               Date II (as hereinafter defined) the Premises, as defined in the
               Lease, is increased to 183,902 rentable square feet which shall
               include 175,660 rentable square feet on the 2nd through 10th
               floors inclusive and 8,242 rentable square feet on the 31st floor
               by the addition of the Expansion Space. From and after Expansion
               Effective Date I, the Original Premises and Expansion Space Il,
               collectively, shall be deemed the Premises, as defined in the
               Lease. From and after Expansion Effective Date II, the Original
               Premises, Expansion Space I and Expansion Space II collectively,
               shall be deemed the Premises as defined in the Lease. The lease
               term for each expansion space shall commence on the applicable
               expansion effective date set forth below and end on December 31,
               2001 (the "Expansion Expiration Date"). The Expansion Space is
               subject to all the terms and conditions of the Lease except as
               expressly modified herein and except that Tenant shall not be
               entitled to receive any allowances, abatements or other financial
               concessions granted with respect to the Original Premises unless
               such concessions are expressly provided for herein with respect
               to the Expansion Space.

               A.   The expansion effective date shall be January 1, 2000
                    ("Expansion Effective Date I") for 6,947 rentable square
                    feet of the Expansion Space ("Expansion Space I") and April
                    1, 2000 ("Expansion Effective Date II") for 1,295 rentable
                    square feet of the Expansion Space ("Expansion Space II").

               B.   Expansion Effective Date I shall be delayed to the extent
                    that Landlord fails to deliver possession of Expansion Space
                    I for any reason, including but not limited to, holding over
                    by prior occupants. Expansion Effective Date II shall be
                    delayed on a day for day basis measured from January 1, 2000
                    to the extent that Landlord fails to deliver possession of
                    Expansion Space II on or before January 4, 2000, for any
                    reason, including but not limited to, holding over by prior
                    occupants. Any such delay in either expansion effective date
                    shall not subject Landlord to any liability for any loss or
                    damage resulting therefrom. If either expansion effective
                    date is delayed, the Expiration Date hereunder shall not be
                    similarly extended.

II.      Monthly Base Rent.
         ------------------
         In addition to Tenant's obligation to pay Base Rent for the Original
         Premises, Tenant shall pay Landlord the Base Rent for the Expansion
         Space as follows:

                                       1
<PAGE>

                                Expansion Space I
<TABLE>
<CAPTION>
                                       Annual Rate             Annual                    Monthly
                  Period            Per Square Foot           Base Rent                 Base Rent
                  ------            ---------------           ---------                 ---------
                  <S>                   <C>                   <C>                       <C>
                  01/01/00-             $20.00                $138,939.96               $11,578.33
                  12/31/00

                  01/01/01-             $20.60                $143,108.16               $11,925.68
                  12/31/01

                               Expansion Space II

                                       Annual Rate             Annual                    Monthly
                  Period            Per Square Foot           Base Rent                 Base Rent
                  ------            ---------------           ---------                 ---------
                  Expansion             $20.00                $25,899.96                $2,158.33
                  Effective Date
                  II - 12/31/00
                                        $20.60                $26,676.96                $2,223.08
                  01/01/01-
                  12/31/01
</TABLE>

                  All such Base Rent shall be payable by Tenant in  accordance
                  with the terms of this Section 2 of the Lease.

         III.     Tenant's Proportion. For the period commencing with Expansion
                  Effective Date I for Expansion Space I and ending on the
                  Expansion Expiration Date, Tenant's Proportion for Expansion
                  Space I is 0.7341%. For the period commencing with Expansion
                  Effective Date II for Expansion Space II and ending on the
                  Expansion Expiration Date, Tenant's Proportion for Expansion
                  Space II is 0.1368%.

         IV.      Rent Adjustment. For the period commencing with Expansion
                  Effective Date I and ending on the Expansion Expiration Date,
                  Tenant shall pay Tenant's Proportion of Expenses and Taxes
                  applicable to Expansion Space I in accordance with the terms
                  of the Lease. For the period commencing with Expansion
                  Effective Date II and ending on the Expansion Expiration Date,
                  Tenant shall pay for Tenant's Proportion of Expenses and Taxes
                  applicable to Expansion Space II in accordance with the terms
                  of the Lease. Tenant shall not be obligated to Landlord for
                  increases in CPI with respect to the Expansion Space.

         V.       Improvements to Expansion Space.

                  A.       Condition of Expansion Space. Tenant has inspected
                           the Expansion Space and agrees to accept the space
                           "as is" without any agreements, representations,
                           understandings, or obligations on the part of
                           Landlord to perform any alterations, repairs or
                           improvements.

                  B.       Cost of Improvements to Expansion Space.  Any
                           construction, alterations or improvements made to the
                           Expansion Space shall be made at Tenant's sole cost
                           and expense.  The improvements to the Expansion Space
                           shall include, but not limited to, any demolition
                           work in the Expansion Space desired by Tenant.  In
                           addition, Tenant specifically agrees to remove the
                           safe currently located outside of the Premises on the
                           31st floor and dispose of the safe in the dumpster
                           for the Building.  If Tenant does not remove the safe
                           by September 30, 1999, Landlord shall perform such
                           work and bill Tenant for any costs associated
                           therewith.

                  C.       Responsibility for Improvements to Expansion Space.
                           Any construction, alterations or improvements to the
                           Expansion Space shall be performed by Tenant using
                           contractors selected by Tenant and approved by
                           Landlord and shall be governed in all respects by the
                           provisions of Section 9 of the Lease.  In any and all
                           events, each Expansion Effective Date shall be
                           postponed or delayed if the initial improvements to
                           an Expansion Space are incomplete on the applicable
                           Expansion Effective Date for any reason whatsoever.
                           Any delay in the completion of initial improvements
                           to the Expansion Space shall not subject Landlord to
                           any liability for any loss or damage resulting
                           therefrom.

         VI.      Early Access to Expansion Space.  During any period that
                  Tenant shall be permitted to enter the Expansion Space prior
                  to the Expansion Effective Date (e.g., to perform alterations
                  or improvements, if any) Tenant shall comply with all terms

                                       2
<PAGE>

                  and provisions of the Lease, except those provisions requiring
                  payment of the Base Rent and Rent Adjustments as to the
                  Expansion Space.  If Tenant takes possession of Expansion
                  Space II prior to Expansion Effective Date II for any reason
                  whatsoever (other than the performance of work in the
                  Expansion Space with Landlord's prior approval), such
                  possession shall be subject to all the terms and conditions of
                  the Lease and this Amendment, and Tenant shall pay Base Rent
                  and Rent Adjustments applicable to Expansion Space II to
                  Landlord on a per diem basis for each day of occupancy prior
                  to Expansion Effective Date II. Expansion Space I was
                  delivered to Tenant on or about September 13, 1999. Expansion
                  Space II will be delivered to Tenant on or before January 1,
                  2000, subject to the provisions of Section I.B. above.

         VII.     LIMITATION OF LIABILITY.  NOTWITHSTANDING ANYTHING TO THE
                  CONTRARY CONTAINED IN THIS AMENDMENT OR THE LEASE, THE
                  LIABILITY OF LANDLORD (AND OF ANY SUCCESSOR LANDLORD
                  HEREUNDER) TO TENANT SHALL BE LIMITED TO THE INTEREST OF
                  LANDLORD IN THE BUILDING, AND TENANT AGREES TO LOOK SOLELY TO
                  LANDLORD'S INTEREST IN THE BUILDING FOR THE RECOVERY OF ANY
                  JUDGEMENT OR AWARD AGAINST THE LANDLORD, IT BEING INTENDED
                  THAT NEITHER LANDLORD NOR ANY MEMBER, PRINCIPAL, PARTNER,
                  SHAREHOLDER, OFFICER, DIRECTOR OR BENEFICIARY OF LANDLORD
                  SHALL BE PERSONALLY LIABLE FOR ANY JUDGEMENT OR DEFICIENCY.

         VIII.    Surrender of Possession. At the Expansion Expiration Date,
                  Tenant shall surrender the Expansion Spaces to Landlord in
                  accordance with Section 21 of the Lease.

         IX.      Other Pertinent Provisions. Landlord and Tenant agree that,
                  effective as of the date hereof, the Lease shall be amended in
                  the following additional respects:

                  Landlord's Addresses. Notwithstanding anything to the contrary
                  contained in the Lease, Landlord's addresses for notices and
                  payments of Rent are as follows:

                  Landlord:

                  EOP -10 & 30 South Wacker, L.L.C.
                  C/o Equity Office Properties Trust
                  30 S. Wacker Drive, Suite 3300
                  Chicago, Illinois 60606
                  Attention:  Building Manager

                  With a copy to:

                  Equity Office Properties Trust
                  Two North Riverside Plaza
                  Suite 2200
                  Chicago, Illinois 60606
                  Attention:  Regional Counsel-Central

                  Payments of Rent only shall be made payable to the order of:

                  Equity Office Properties

                  at the following address:

                  EOP Operating Limited Partnership
                  DBA 10 & 30 South Wacker Drive
                  Dept.  77-72058
                  Chicago, Illinois  60678-2058

         X.       Miscellaneous.

                  A.       This Amendment sets forth the entire agreement
                           between the parties with respect to the matters set
                           forth herein. There have been no additional oral or
                           written representatives or agreements. Under no
                           circumstances shall

                                       3
<PAGE>

                           Tenant be entitled to any Rent abatement, improvement
                           allowance, leasehold improvements, or other work to
                           the Premises, or any similar economic incentives that
                           may have been provided Tenant in connection with
                           entering into the Lease, unless specifically set
                           forth in this Amendment.

                  B.       Except as herein modified or amended, the provisions,
                           conditions and terms of the Lease shall remain
                           unchanged and in full force and effect.

                  C.       In the case of any inconsistency between the
                           provisions of the Lease and this Amendment, the
                           provisions of this Amendment shall govern and
                           control.

                  D.       Submission of this Amendment by Landlord is not an
                           offer to enter into this Amendment but rather is a
                           solicitation for such an offer by Tenant. Landlord
                           shall not be bound by this Amendment until Landlord
                           has executed and delivered the same to Tenant.

                  E.       The capitalized terms used in this Amendment shall
                           have the same definitions as set forth in the Lease
                           to the extent that such capitalized terms are defined
                           therein and not redefined in this Amendment.

                  F.       Tenant hereby represents to Landlord that Tenant has
                           dealt with no broker in connection with this
                           Amendment except for The Levy Organization
                           ("Broker"). Tenant agrees to indemnify and hold
                           Landlord, its members, principals, beneficiaries,
                           partners, officers, directors, employees,
                           mortgagee(s) and agents, and the respective
                           principals and members of any such agents
                           (collectively, the "Landlord Related Parties")
                           harmless from all claims of any brokers, other than
                           Broker, claiming to have represented Tenant in
                           connection with this Amendment. Landlord hereby
                           represents to Tenant that Landlord has dealt with no
                           broker in connection with this Amendment. Landlord
                           agrees to indemnify and hold Tenant, its members,
                           principals, beneficiaries, partners, officers,
                           directors, employees, and agents, and the respective
                           principals and members of any such agents
                           (collectively, the "Tenant Related Parties") harmless
                           from all such claims of any brokers claiming to have
                           represented Landlord in connection with this
                           Amendment.

         IN WITNESS WHEREOF, Landlord and Tenant have duly executed this
Amendment as of the day and year first written above written.

                                 LANDLORD: EOP-10 & 30 SOUTH WACKER, L.L.C., a
                                           Delaware Limited liability company,
                                           as beneficiary of land Trust dated
                                           October 1, 1997, and known as
                                           American National Bank and Trust
                                           Company of Chicago Trust No.
                                           123434-06

                                     By: EOP Operating Limited Partnership, a
                                         Delaware limited Partnership, its sole
                                         member

                                        By: Equity Office Properties Trust, a
                                            Maryland real estate Investment
                                            trust, its managing general partner

                                            By: /s/ George Kohl
                                               -----------------------------
                                            Name:   George Kohl
                                                 ---------------------------
                                            Title:  Vice President Leasing
                                                  --------------------------

                                 TENANT: CHICAGO MERCANTILE EXCHANGE, An
                                         Illinois not-for-profit corporation

                                     By: /s/ David Gomach
                                        ------------------------------------
                                     Name: David Gomach
                                          ----------------------------------
                                     Title: CFO
                                           ---------------------------------

                                       4<PAGE>

                                               Exhibit 10.16
                                               Chicago Mercantile Exchange, Inc.
                                              Registration Statement on Form S-4

          BUILDING:          30 SOUTH WACKER DRIVE
                   ---------------------------------------------

                                Chicago, Illinois

                                      LEASE

         AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, AS TRUSTEE
         ---------------------------------------------------------------
                                    LANDLORD

                          CHICAGO MERCANTILE EXCHANGE,
                     an Illinois not-for-profit corporation
         ---------------------------------------------------------------
                                     TENANT

         100,000 Square Feet on the Upper Lobby Level and 2nd-6th Floors
         ---------------------------------------------------------------
                                    PREMISES

                                  May 11, 1981
         ---------------------------------------------------------------
                                  DATE OF LEASE
<PAGE>

         THIS LEASE, made as of this 11th day of May, 1981,
between           AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, Illinois,
                  a national banking association of Chicago, Illinois, a
                  national banking association of Chicago, Illinois, not
                  individually but solely as Trustee under the provisions of a
                  certain Trust Agreement dated March 20, 1980 and known as
                  Trust No. 48268.

(hereinafter known as "Landlord"), and
                  CHICAGO MERCANTILE EXCHANGE,
                  an Illinois not-for-profit corporation

(hereinafter known as "Tenant"):

                                  WITNESSETH:
         THAT Landlord hereby leases to Tenant, and Tenant accepts the demised
premises (hereinafter known as "demised premises" or "premises"), being 100,000
Square Feet on the Upper Lobby level and 2nd - 6th Floors and described in the
plan attached hereto as Exhibits "A-1" - "A-6" in the building (hereinafter
known as "Building"), known as 30 South Wacker Drive Chicago, Illinois, for the
term of twenty (20) years unless sooner terminated as provided herein,
commencing on the Commencement Date (defined in Section 2(a) (xxvi)) and ending
twenty (20) years thereafter ("Termination Date"),

                                            to be occupied and used by Tenant
for general offices of a mercantile exchange (and other uses associated
therewith) and no other purpose, subject to the agreements herein contained.

IN CONSIDERATION THEREOF, THE PARTIES COVENANT AND AGREE:

         1. BASE RENT. Tenant shall pay as Base Rent to JMB/MS Management Co. at
111 East Wacker Drive, Chicago, Illinois, or to such other person or at such
other place as Landlord may direct in writing, in lawful money of the United
States of America, the sum of THIRTY-NINE MILLION FIVE HUNDRED THOUSAND ONE AND
60/100 Dollars ($39,500,001.60) in two hundred forty (240) equal monthly
installments of ONE HUNDRED SIXTY-FOUR THOUSAND FIVE HUNDRED EIGHTY-THREE AND
34/100 Dollars ($164,583.34) in advance on or before the first day of each month
of the term, except that Tenant shall pay the first such monthly installment on
July 1, 1983. All such Base Rent shall be paid without any set-off or deduction
whatsoever as otherwise provided in this lease. Unpaid Base Rent shall bear
interest at the rate set forth in Section 24(f), from twenty (20) days after the
date due until paid. Time is of the essence of this Lease. Tenant agrees to do
and perform each and every covenant, agreement and obligation to be performed by
Tenant hereunder.

         2. RENT ADJUSTMENT. The Base Rent shall be adjusted in accordance with
the provisions of this Section 2.

(a)      For purposes of this Lease:

                      (i) "Base Year" means the portion of the calendar year for
                the period commencing on the Commencement Date and ending on
                December 31st of the calendar year in which the Commencement
                Date occurs.

                      (ii) "Calculation Year" means the calendar year for which
                a Rent Adjustment computation is being made.

                                       1
<PAGE>

                      (iii) "Consumer Price Index" ("CPI") means the average of:
                1) U.S. City Averages for all Urban Consumers. All Items, of the
                United States Bureau of Labor Statistics: and 2) U.S. City
                Averages for Urban Wage Earners and Clerical Workers. All items,
                of the United States Bureau of Labor Statistics. The CPI for any
                calendar year for portion thereof in the [unreadable text] of
                the Base Year and the last calendar year of the Lease term)
                shall be determined by first averaging the monthly indices for
                each index and then averaging the two indices (All Items).

                      (iv) "Expenses" means and includes: 1) those expenses paid
                or incurred by Landlord for maintaining, operating and repairing
                the Real Property, the cost of electricity, steam, water, fuel,
                heating, lighting, air conditioning, window cleaning, janitorial
                service, insurance, including but not limited to, fire, extended
                coverage, liability, workmen's compensation, elevator, or any
                other insurance carried in good faith by Landlord and applicable
                to the Real Property, painting, uniforms, customary management
                fees, supplies, sundries, sales or use taxes on supplies or
                services, cost of wages and salaries of all persons engaged in
                the operation, maintenance and repair of the Real Property, and
                so-called fringe benefits, including social security taxes,
                unemployment insurance taxes, cost for providing coverage for
                disability benefits, cost of any pensions, hospitalization,
                welfare or retirement plans, or any other similar or like
                expenses incurred under the provisions of any collective
                bargaining agreement, or any other cost or expense which
                Landlord pays or incurs to provide benefits for employees so
                engaged in the operation, maintenance and repair of the Real
                Property, the charges of any independent contractor who, under
                contract with Landlord or its representatives, does any of the
                work of operating, maintaining or repairing of the Real
                Property, legal and accounting expenses, including, but not to
                be limited to, such expenses as relate to seeking or obtaining
                reductions in and refunds of Taxes (which Landlord shall use
                reasonable efforts to obtain) , or any other expense or charge,
                whether or not hereinbefore mentioned, which in accordance with
                generally accepted accounting and management principles would be
                considered as an expense of maintaining, operating, or repairing
                the Real Property, and 2) the amortized portion of the cost of
                any capital improvement made to the Real Property which is
                either required by law (or governmental regulation) or
                reasonably intended by Landlord to reduce Expenses. Such
                amortization shall be in accordance with generally accepted
                accounting principles and include interest at the prime rate in
                effect on the date of installation of the capital improvement.
                The term "Expenses" shall not include: (I) leasing brokerage
                commissions, (ii) promotional and other expenses related to the
                leasing of space in the Building, (iii) expenses for an
                individual tenant for which Landlord is reimbursed directly by
                such other tenant, (other than through Rent Adjustments), (iv)
                items paid by insurance or utility charges billed directly to
                tenants by Landlord, (v) repairs or replacements caused by fire
                or other casualty, (vi) the cost of tenant alterations or
                improvements, (vii) depreciation and debt service, (viii)
                management overhead and fees not related to the Building or the
                Real Property. If the Building is not fully rented during all or
                a portion of any calendar year, Landlord shall make an
                appropriate adjustment of the Expenses, for each calendar year
                employing sound accounting and management principles, to
                determine the amount of Expenses that would have been paid or
                incurred by Landlord had the Building been fully tented; and the
                amount so determined shall be deemed to have been the amount of
                Expenses for each calendar year, provided however, for the
                calendar year in which the first (1st) Anniversary occurs, this
                procedure shall be employed only for the period commencing on
                the first (1st) Anniversary and ending on December 31st. If any
                Real Property expense, though paid in one year, relates to more
                than one calendar year, at the option of Landlord such expense
                may be proportionately allocated among such related calendar
                years.

                      (v) "Real Property" means the Building, the land parcel
                upon which it stands and the personal property used in
                conjunction with both.

                      (vi) "Rent Adjustment" means any amount owed by Tenant
                resulting from increases in CPI, Expenses or Taxes. The Rent
                Adjustment shall be paid in addition to and in the same manner
                as Base Rent. Landlord's corrections for the expense and tax
                portion of the rent adjustment from all tenants in the Building
                including Tenant and Members may not exceed 100% of the total
                Building Rent Adjustments for Expenses and Taxes. The portion of
                the Building Rent Adjustments attributable to Expenses and Taxes
                billed to retail tenants, in the Building (including the Club
                (Section 38) and Retail Space (Section 36)) shall be deducted
                from the Building total for purposes of calculating Tenant's
                proportionate amount under this Lease.

                      (vii) "Rentable Area of the Building" is 993,040 square
                feet which is the sum of the rentable area of all demised
                premises (leased or unleased) in the Building on floors
                designated by Landlord as office floors.

                      (viii) "Rentable Area of the demised premises" is 100,000
                square feet which: 1) if this Lease is for an entire office
                floor, is the area of the entire floor inside the center line of
                the exterior glass walls (except public stairs, elevator shafts,
                flues, stacks, pipe shafts and vertical ducts) plus a
                proportionate share of Building mechanical (HVAC) spaces above
                the lobby floor, or 2) if this Lease is for less than an entire
                office floor, is the area measured from the center line of the
                exterior glass walls to the center line of corridor partitions
                or other demising partitions plus a) a proportionate share of
                Building public areas (including corridors), toilets, mechanical
                (HVAC) spaces and janitors, electrical and telephone closets, on
                the floor housing the demised premises, and b) a proportionate
                share of Building mechanical (HVAC) spaces above the lobby
                floor. In either case, no deduction is made for columns or
                Building projections.

                      (ix) "Rent Adjustment Deposit" shall be equal to the Rent
                Adjustments due for the Calculation Year divided by the number
                of months within the Lease term in the Calculation Year.

                      (x) "Taxes" means real estate taxes, assessments, sewer
                rents, rates and charges, transit taxes, taxes based upon the
                receipt of rent, and any other federal, state or local
                governmental charge, general, special, ordinary or extraordinary
                (but not including income or franchise taxes or any other taxes
                imposed upon or

                                       2
<PAGE>

                measured by Landlord's income or profits, unless the same shall
                be imposed in lieu of real estate taxes), which may now or
                hereafter be levied or assessed against the Real Property. In
                case of special taxes or assessments which may be payable in
                installments, only the amount of each installment paid during a
                calendar year shall be included in Taxes for that year. Taxes
                shall also include any personal property taxes (attributable to
                the year in which paid) imposed upon the furniture, fixtures,
                machinery, equipment, apparatus, systems and appurtenances used
                in connection with the Real Property for the operation thereof.
                The amount of Taxes attributable to any calendar year of the
                Lease term shall be the amount of Taxes payable in such year,
                notwithstanding that in each case the assessments for such Taxes
                may have been made for a different year or years than the year
                in which payable. In the event the Real Property is not assessed
                as fully improved for any year, then commencing on the first
                (1st) Anniversary. Taxes shall be adjusted to the Taxes which
                would have been payable in such year if the assessment of the
                Real Property had been made on a fully improved basis provided
                however, for the calendar year in which the first (1st)
                Anniversary occurs, this procedure shall be employed only for
                the period commencing on the first (1st) Anniversary and ending
                on December 31st.

                      (xi) "Tenant's Proportion" is 10.070 and means the
                proportion the Rentable Area of the premises bears to the
                Rentable Area of the Building.

                    Section 2(a) is continued on page 3(a).

                            (b) If the CPI for the Base Year is less than the
                CPI for any calendar year of the Lease term, commencing with the
                calendar year in which the 37th month of the Lease term occurs,
                Tenant shall pay Landlord as a Rent Adjustment for each such
                calendar year, the sum of the Base Portion, Additional Portion
                and Constant Portion. For the calendar year in which the 37th
                month of the Lease term occurs, the CPI portion of the Rent
                Adjustment need be paid only for the period commencing on the
                first (1st) day of the 37th month and ending December 31st. (see
                example page 43 and limitation Section 54).

                      Section 2(c) intentionally omitted.

                            (d) If the total amount of Taxes and/or Expenses
                attributable to any calendar year of the Lease term is greater
                than $5,461,720.00 then Tenant shall pay Landlord as a Rent
                Adjustment for such calendar year, Tenant's Proportion of such
                amount.

                            (e) Tenant shall pay Landlord the Rent Adjustment
                Deposit in the same manner as Base Rent, on the first day of
                each month during the term of this Lease commencing with the
                first day of the calendar year following the calendar year in
                which this Lease commences. The Rent Adjustment Deposit shall be
                deposited against Rent Adjustments due for the calendar year
                next following the Calculation Year. During the last complete
                calendar year or during any partial calendar year which this
                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.

                            (f) As soon as reasonably feasible after the
                expiration of each calendar year of this Lease, Landlord will
                furnish Tenant's statement (which has been audited by a
                Certified Public Accounting Firm) showing the following:

                            (i)     Expenses, Taxes and CPI for the Calculation
                                    Year.

                            (ii)    CPI for the Base Year;

                            (iii)   The amount of Rent Adjustments due Landlord
                                    for the Calculation Year, less credits for
                                    Rent Adjustment Deposits paid, if any. If
                                    Landlord receives a reduction in the Taxes
                                    for any year and if Tenant has paid a Rent
                                    Adjustment based upon the taxes prior to the
                                    reduction, Tenant shall receive a refund of
                                    such adjustment paid which Landlord shall
                                    credit to Tenant's Base Rent account. Upon
                                    notice to Landlord, Tenant may request
                                    direct payment in lieu of such credit; and

                            (iv)    The Rent Adjustment Deposit due in the
                                    calendar year next following the Calculation
                                    Year including the amount or revised amount
                                    due for the months prior to the rendition of
                                    the statement. Tenant may request and obtain
                                    a copy of auditor's certification.

                            (g) If the Lease term commences on any day other
                than the first day of January, or if the Lease term ends on any
                day other than the last day of December, any Rent Adjustment
                payment due Landlord shall be prorated, and Tenant shall pay
                such amount within thirty (30) days after being billed. This
                covenant shall survive the expiration or termination of this
                Lease.

                            (h) If the Bureau of Labor Statistics substantially
                revises the manner in which the CPI is determined, Landlord
                shall use the CPI as revised. If however, the 1977 average shall
                no longer be used as an index of 100, such change shall
                constitute a revision which will entitle Landlord to produce
                results equivalent, as nearly as possible, to those which would
                be obtained if the 1977 average were still being used as an
                index of 100. If such CPI becomes unavailable to the public
                because publication is discontinued, or otherwise, Landlord and
                Tenant shall 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.

                                       3
<PAGE>

Section 2(a) continued:                              **continued on page 42(a)

                   2(a)(xii) "Trading Floor" is the floor to be constructed
                            abutting the Building.

                            Tenant agrees:
                            1. to equip and outfit the Trading Floor for use and
                            operation as the trading floor of the Chicago
                            Mercantile Exchange, and
                            2. to open for business in the Trading Floor as the
                            trading floor of the Chicago Mercantile Exchange on
                            or prior to the later of:
                                    i. eighteen (18) months after purchase of
                                    the Trading Floor pursuant to Trading Floor
                                    Agreement referred to in section 34.C.,
                                    or
                                    ii. July 31, 1985 as extended by Force
                                    Majeures but not later than April 1, 1987.

                      (xiii) "Phase II Tower" is the tower of a building which
                may be constructed on the property immediately north of the
                Building. It is understood that the Phase II Tower may never be
                built.** (continued on page 42(a))

                      (xiv) "Anniversary" means the annual recurrence of the
                Commencement Date.

                      (xv)  "Base Rent Rate Per Square Foot" means the sum
                calculated as follows:

                            (current monthly installment
                            of Base Rent) x 12
                            ----------------------------  = Base Rent Rate
                            (current Rentable Area of       Per Square Foot
                            the demised premises)

                      (xvi) "Rent Adjustment Rate Per Square Foot" means the sum
                calculated as follows:

                            (Rent Adjustments attributable
                            to current month) x 12
                            ------------------------------- = Rent Adjustment
                            (current Rentable Area of the     Rate Per Square
                            demised premises)                 Foot

                      (xvii) "Prevailing Market" is, and at any time shall be
                determined by considering leases for "as-is" space ("As-Is
                Leases") being entered into at such time in the Building or the
                Phase II Tower giving appropriate consideration to rate per
                square foot, escalation and abatement provisions, if any, length
                of lease term, size and location of premises being leased, work
                or allowances, if any, and other applicable terms and conditions
                of tenancy; provided however, there shall be excluded from a
                consideration of Prevailing Market As-Is Leases entered into
                under "special circumstances" which includes the following
                (among others):

                         1.       Landlord being forced to lease
                         2.       a term of less than five (5) years
                         3.       options encumbering the space being leased
                         4.       awkward or unusual shape
                         5.       lack of windows.

                If no As-Is Leases are then being entered into in the Building
                or Phase II Tower the same process stated in the preceding
                sentence shall be used by As-Is Leases in reasonably similar
                neighboring first class high rise office buildings shall be the
                ones considered. When this Lease and Member's leases are amended
                to reflect Prevailing Market, such leases shall be amended, as
                required, to reflect any changes in rate per square foot,
                escalation, abatement, lease term, size and location of
                premises, work or allowances and any other applicable terms and
                conditions of tenancy.

                      (xviii) "Force Majeure" means interruptions or delays
                caused by; war, insurrection, civil commotion, riots, acts of
                God or enemy, governmental action, strikes, lockouts, picketing
                (legal or illegal), accidents, inability of Landlord to obtain
                fuel, supplies or materials, or any other cause or causes beyond
                the control of Landlord.

                      (xix) "Acts of Tenant" means interruptions or delays
                caused by; acts, defaults or omissions of Tenant, special work,
                changes,

                                      3(a)
<PAGE>

                alterations or additions required or made by Tenant in the
                layout or finish of the premises or the Building, Tenant's delay
                in submitting plans, supplying information, approving plans,
                specifications or estimates or giving authorizations or Tenant's
                request for items requiring long delivery periods.

                      (xx) "Ready for Occupancy" means that state of readiness
                when only minor insubstantial details of construction,
                decoration or mechanical adjustments remain to be done in the
                premises or any part thereof or the Building (excluding Tenant
                work in places other than the demised premises and in any
                portion of the demised premises being constructed by a general
                contractor other than Metropolitan Structures, Inc.). In the
                event of dispute as to whether the premises are Ready for
                Occupancy, the decision of Landlord's architect shall be final
                and binding on Landlord and Tenant.

                      (xxi) "Base Portion" means the product derived by
                multiplying thirty percent (30%) of the Base Rent due for a
                Calculation Year (which shall not be diminished by credits) by
                the quotient of the following division: the CPI for the Base
                Year, and the remainder thereof divided by the CPI for the Base
                Year.

                Base Portion = 30% x Base Rent x (Calculation Year CPI minus)
                                                 (Base Year CPI             )
                                                 (--------------------------)
                                                 (        Base Year CPI     )

                      (xxii)  "Additional Portion" means;

                            1. (a) through December 31st of the calendar year in
                which the 120th month of the Lease term occurs, the product
                derived by multiplying the CPI portion of the Rent Adjustment
                for the calendar year prior to the Calculation Year by thirty
                percent (30%) and multiplying the product so derived by the
                quotient of the following division: the CPI in such Calculation
                Year less the CPI for the Base Year, and the remainder thereof
                divided by the CPI for the Base Year.

                Additional Portion = 30% x (CPI portion  )   (Calculation Year)
                                           (of Rent Ad-  )   (CPI minus Base  )
                                           (justment for ) x (Year CPI        )
                                           (calendar year)   ------------------
                                           (prior to Cal-)      Base Year CPI
                                           (culation Year)

                               (b) In no event shall the quotient referred to in
                2(a) (xxii)(1)(a) exceed the following limitation factor in the
                year indicated:

CALENDAR YEAR                                              LIMITATION
OF LEASE TERM                                              FACTOR
-------------                                              ----------
The calendar year in which the 13th month
of Lease term occurs                                          .06000

The next succeeding calendar year (i.e.,
the calendar year in which the 25th month
of the Lease term occurs)                                     .123600

                                      (3b)
<PAGE>

The next succeeding calendar year                             .191016

The next succeeding calendar year                             .262477

The next succeeding calendar year                             .338226

The next succeeding calendar year                             .418519

The next succeeding calendar year                             .503630

The next succeeding calendar year                             .593848

The next succeeding calendar year                             .689479

The next succeeding calendar year                             .790848

                            2. (a) for the calendar year following the calendar
                year in which the 120th month of the Lease term occurs through
                the end of the original Lease term (not the Extension), the
                product derived by multiplying the CPI portion of the Rent
                Adjustment for the calendar year prior to the Calculation Year
                by thirty percent (30%) and multiplying the product so derived
                by the quotient of the following division: the CPI in such
                Calculation Year less the CPI for the calendar year in which the
                120th month of the Lease term occurs, and the remainder thereof
                divided by the CPI for the calendar year in which the 120th
                month of the Lease term occurs.

                Additional   30% x (CPI portion  )   (Calculation Year CPI    )
                Portion    =       (of Rent Ad-  )   (minus CPI for calendar  )
                                   (justment for ) x (year in which the 120th )
                                   (calendar year)   (month of the Lease term )
                                   (prior to Cal-)   (occurs                  )
                                   (culation Year)   (----------------------- )
                                                     (CPI for calendar year   )
                                                     (in which the 120th month)
                                                     (of the lease term occurs)

                                    (b) In no event shall the quotient referred
                to in 2(a) (xxii)(2)(a) exceed the following limitation factor
                in the year indicated:

CALENDAR YEAR                                                    LIMITATION
OF LEASE TERM                                                      FACTOR
-------------                                                    ----------
The calendar year following the
calendar year in which the 120th month of the
Lease term occurs (i.e., the calendar year in
which the 132nd month of the Lease term occurs)                   .06000

The next succeeding calendar year (i.e.,
the calendar year in which the 144th month
of the Lease term occurs)                                         .123600

The next succeeding calendar year                                 .191016

The next succeeding calendar year                                 .262477

The next succeeding calendar year                                 .338226

The next succeeding calendar year                                 .418519

The next succeeding calendar year                                 .503630

The next succeeding calendar year                                 .593848

The next succeeding calendar year                                 .689479

The next succeeding calendar year                                 .790848

                 * See note to Section 2(a) (xxii) on page 3(e)

                                  (3c)
<PAGE>

                      (xxiii)  "Constant Portion" means;

                            1. for the calendar year in which the 37th month of
                      the Lease term occurs through December 31st of the
                      calendar year in which the 120th month of the Lease term
                      occurs, zero, and

                            2. for the calendar year following the calendar year
                      in which the 120th month of the Lease term occurs through
                      the end of the original Lease term, an amount equal to the
                      Additional Portion for the calendar year in which the
                      120th month of the Lease term occurs. Note: This amount
                      remains constant.

                      (xxiv) "General Conditions" means field office costs,
                clean up, data processing, hoisting, meals and travel,
                supervision, administration, accounting and secretarial
                services, rubbish removal, temporary enclosures, equipment
                rental, temporary services, and building permits.

                      (xxv) "Acts of a Member" means interruptions or delays
                caused by; acts, defaults or omissions of a member, special
                work, changes, alterations or additions required or made by a
                Member in the layout or finish of the premises or the Building,
                a Member's delay in submitting plans, supplying information,
                approving plans, specifications or estimates or giving
                authorizations or a Member's request for items requiring long
                delivery periods.

                      (xxvi) "Commencement Date" means the first day of the
                calendar month immediately following the month in which Landlord
                gives notice to Tenant that the demised premises are Ready for
                Occupancy (defined in Section 2(a) (xx)), provided however, that
                if the Commencement Date occurs before the first (1st) day of
                the month next following the twenty-eighth (28th) month after
                the month during which Landlord obtains a Foundation Permit,
                unless Tenant chooses to occupy and thereby establish the
                Commencement Date, the Commencement Date shall be deemed delayed
                until the first (1st) day of the month next following the
                twenty-eighth (28th) month after the month during which Landlord
                obtains a Foundation Permit.

                      (xxvii) "Additional Portion Rate Per Square Foot" means
                the quotient derived by dividing the Additional Portion for any
                calendar year by the then current Rentable Area of the demised
                premises.

                      (xxviii) "Constant Portion Rate Per Square Foot" means the
                quotient derived by dividing the Constant Portion for any
                calendar year by the then current Rentable Area of the demised
                premises.

                      (xxix) "Base Portion Rate Per Square Foot" means the
                quotient derived by dividing the Base Portion for any calendar
                year by the then current Rentable Area of the demised premises.

                      (xxx) "Holiday(s)" means national and state holidays
                including but not limited to: New Year's Day, Memorial Day,
                Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

                                      (3d)
<PAGE>

                      (xxxi) "Expansion Floor" is described in section 1.5 of
                the agreement called The Chicago Mercantile Exchange Center
                Easements, Reservations, Covenants and Restrictions, by and
                between American National Bank and Trust Company of Chicago, as
                Trustee under Trust No. 48268, American National Bank and Trust
                Company of Chicago, as Trustee under Trust No. 51234, American
                National Bank and Trust Company of Chicago, as Trustee under
                Trust No. 51235.

Note to Section 2(a) (xxii):

         For the calendar year in which the twenty-fifth (25th) month of the
Lease term occurs for the Second Reservation Space and the calendar year in
which the forth-ninth (49th) month of the Lease term occurs for the First
Reservation Space, for the purposes of calculating the Additional Portion (for
such years only), the CPI portion of the Rent Adjustment (which is determined
from the calendar year prior to such Calculation Year) shall be multiplied by
the ratio of the number of months from the Commencement Date to December 31st of
the first calendar year of the Lease bears to 12; e.g., if the Commencement Date
is September 1, the ration is 4/12.

         For the calendar year in which the sixtieth (60th) month occurs (for
leases to Members with five (5) year terms) and for the calendar years in which
the one hundred twentieth (120th) or two hundred fortieth (240th) month of the
Lease term occurs (as appropriate for Members with ten (10) year terms, or
Tenant) for the First Reservation Space and the 60th or the 120th month of the
Lease term for the Second Reservation Space, for the purposes of calculating the
Additional Portion (for such years only), the CPI portion of the Rent Adjustment
(which is determined from the calendar year prior to such Calculation Year)
shall be multiplied by the ratio of twelve (12) minus the number of months from
the Commencement Date to December 31st of the first calendar year of the Lease
term bears to 12, e.g., if the Commencement Date is September 1, the ratio is
8/12.

                                      (3e)
<PAGE>

Date Sent      Drawing No.     Drawing Date         Description
---------      -----------     ------------         -----------
12/31/81        A1 - A24         12/19/80        "Pricing" Drawings
 3/12/81        A1 - A22          3/09/81        "P.U.D." Drawings
 4/1/81         A1 - A22          3/09/81        "P.U.D." Drawings

Drawings Sent to The Levy Organization:
---------------------------------------

Date Sent      Drawing No.     Drawing Date         Description
---------      -----------     ------------         -----------
1/06/81         A1 - A24         12/19/80        "Pricing" Drawings
3/12/81         A1 - A22          3/09/81        "P.U.D." Drawings

Drawings Sent to Space/Management Programs:
-------------------------------------------

Date Sent      Drawing No.     Drawing Date         Description
---------      -----------     ------------         -----------
1/30/81         A1 - A24         12/19/80        "Pricing" Drawings
2/06/81          -----            1/28/81        Preliminary 1/4" core plans
3/12/81         A1 - A22          3/09/81        "P.U.D." Drawings
3/19/81          -----            3/18/81        Preliminary Core Plans
                                                 for P-1, P-2, Floors 8, 9,
                                                 11 - 40
3/26/81          -----            3/26/81        Preliminary Low-Rise,
                                                 Floors #2 - 10
3/31/81         A - 43            3/31/81        Preliminary 2nd Floor
4/9/81          DSK-154A          1/19/81        Section Showing Escalators
4/16/81         A12, 13, 16
                to 25, 44         4/20/81        Preliminary Substructure
                                                 Permit Drawings
4/20/81         A1 - A44;         4/20/81        Caisson and Substructure
                S1-S16, except                   Permit Drawings
                S3; Survey 1 & 2;
                PC1; P1-P5; E2,E3
                Pile Dyne Drawings  4/15/81
                No. 1, 2 and 3

                                                               Attachment "C"
<PAGE>

                      (i) Tenant or its representative shall have the right to
                examine Landlord's books and records with respect to the items
                in the statement of Expenses and Taxes during normal business
                hours at any time within forty-five (45) days following the
                furnishing of the statement to Tenant. Unless Tenant takes
                written exception to any item within ninety (90) days after the
                furnishing of the statement (which shall be noted on the item as
                "paid under protest"), such statement shall be considered as
                final and accepted by Tenant. Any amount due Landlord as shown
                on any such statement shall be paid by Tenant within thirty (30)
                days after it is furnished to Tenant. If an audit by tenant
                reveals an overcharge to Tenant in excess of five percent (5%),
                Landlord shall pay the cost of such audit.

3.       SERVICE.

         (a)      Landlord, as long as Tenant is not in default under any of the
                  covenants of this Lease, shall furnish:

                      (i)   Air-cooling when necessary to provide a temperature
                condition required, in Landlord's judgment or required by law
                (or governmental regulation), for comfortable occupancy of the
                demised premises under normal business operation, daily from
                7:00 A.M. to 6:00 P.M. (Saturdays 8:00 A.M. to 1:00 P.M.).
                Sundays and holidays excepted. Wherever heat generating machines
                or equipment are used by Tenant in the demised premises, which
                affect the temperature otherwise maintained by the air-cooling
                system, Landlord reserves the right to install supplementary
                air-conditioning units in the demised premises and the expense
                of installation shall be paid by Tenant. The expense resulting
                from the operation and maintenance of the supplementary
                air-conditioning systems shall be paid by Tenant to Landlord as
                additional Base Rent at rates fixed by Landlord. Landlord agrees
                to furnish heat to the demised premises, when required by law
                (or governmental regulation) for comfortable occupancy of the
                demised premises under normal business operation on business
                days from 7:00 A.M. to 6:00 P.M. and on Saturdays from 8:00 A.M.
                to 1:00 P.M. Upon prior written notice to Landlord, Tenant may
                request heating or air-cooling during hours other than those
                stated and Landlord shall provide such at Tenant's sole expense
                which shall be based upon Landlord's cost plus fifteen percent
                (15%) overhead and profit;

                      (ii) Landlord shall supply hot and cold water for use in
                lavatories it installs for use in common with other tenants or
                for full floor tenants. If Tenant desires water in the demised
                premises, cold water only shall be supplied from City of Chicago
                mains drawn through a line, meter, and fixtures installed by
                Tenant, at Tenant's expense, with Landlord's written consent.
                Tenant shall pay Landlord as additional Base Rent, at rates
                fixed by Landlord (Landlord's cost plus fifteen percent (15%)
                overhead and profit) charges for all water furnished in the
                demised premises. Tenant shall not waste or permit the waste of
                water. If Tenant fails to pay landlord's charges for water
                within twenty (20) days after billing. Landlord upon ten (10)
                days' notice, may in addition to any other remedy provided in
                this Lease, discontinue furnishing water. No such discontinuance
                shall be deemed an eviction or disturbance of Tenant's use of
                the demised premises or render Landlord liable for damages or
                relieve Tenant from any obligation under this Lease;

                      (iii) Passenger elevator service in common with Landlord
                and other tenants, daily from 7:00 A.M. to 6:00 P.M. (Saturdays
                to 1:00 P.M.). Sundays and holidays excepted, and on an
                emergency basis only, freight elevator service on common with
                Landlord and other tenants, daily from 7:00 A.M. to 5:00 P.M..
                Saturdays, Sundays and holidays excepted [unreadable text] the
                way down at the Trading Floor and Expansion Floor levels. Such
                normal elevator service, passenger or freight, on an emergency
                basis only, if furnished at other times shall be optional with
                Landlord and shall never be deemed a continuing obligation.
                Landlord, however, shall provide limited passenger elevator
                service daily at all times such normal passenger service is not
                furnished provided further, that Tenant's freight elevator shall
                be available 24 hours per day. Operatorless automatic passenger
                and on an emergency basis only, freight elevator service shall
                be deemed "elevator service" within the meaning of this
                paragraph;

                      (iv) Janitor service and customary cleaning in and about
                the demised premises in accordance with Exhibit "D", Saturdays,
                Sundays and holidays excepted. Tenant shall not provide any
                janitor services or cleaning without Landlord's written consent
                and then only subject to supervision of Landlord and at Tenant's
                sole responsibility and by janitor or cleaning contractors or
                employees at all times satisfactory to Landlord;

                      (v) Window washing of all windows in the demised premises,
                both inside and out, at such times as shall be required in
                Landlord's sole judgment provided however, that the windows
                shall be washed no less than three (3) times per year, weather
                permitting;

                Notwithstanding anything hereinafter contained in this Lease,
there shall be no abatement or reduction of that portion of the Base Rent which
represents the amount of the charges for supplementary air-conditioning and
water in the demised premises pursuant to this section 3(a).

                (b) All electricity used in the demised premises shall be
         supplied by the utility company serving the Building through a separate
         meter and be paid for by Tenant. Landlord shall not in any way be
         liable or responsible to Tenant for any loss or damage or expense which
         Tenant may sustain or incur if either the quantity or character of
         electric service is changed or is no longer available or suitable for
         Tenant's requirements. If such service be discontinued, such
         discontinuance shall not in any way affect this Lease or the liability
         of Tenant hereunder or cause a diminution of Base Rent or Rent
         Adjustments and the same shall not be deemed to be a lessening or
         diminution of services within the meaning of any law, rule or
         regulation now or hereafter enacted, promulgated or issued. Tenant
         shall receive such service directly from the utility company and
         Landlord hereby permits its wires and

                                       4
<PAGE>

         conduits to the extent available, suitable and safely capable, to be
         used for such purposes. Tenant shall make no alteration or additions to
         the electric equipment and/or appliances without the prior written
         consent of Landlord in each instance. Tenant may at its option,
         purchase from Landlord or its agent all lamps, bulbs, ballast and
         starters used in the demised premises after their initial installation.
         Tenant covenants and agrees that at all times its use of electric
         current shall never exceed the capacity of the feeders to the building
         or the risers or wiring installation;

                (c) Landlord does not warrant that any of the services above
         mentioned will be free from interruptions caused by Force Majeure. Any
         such interruption of service shall never be deemed an eviction or
         disturbance of Tenant's use an possession of the premises or any part
         thereof, or render Landlord liable to Tenant for damages, or relieve
         Tenant from performance of Tenant's obligations under this Lease,
         [unreadable text] any interruption in HVAC or any repairs, renewals,
         improvements or alterations to the demised premises cause the demised
         premises or any part thereof to be rendered untenantable or
         inaccessible by Tenant for more than thirty (30) consecutive business
         days, Landlord agrees that Base Rent and Rent Adjustments shall abate
         on a per diem basis for each day after such thirty (30) day period
         during which the premises or any part thereof are not tenantable or
         accessible prorated, however, in proportion to the portion of the
         demised premises which are so rendered untenantable or inaccessible to
         the total demised premises.

         4. CONDITION OF PREMISES. Subject to the Work Letter attached to this
Lease and a construction "punch list", Tenant's taking possession shall be
conclusive evidence as against Tenant that the demised premises were in good
order and satisfactory condition when Tenant took possession. No promise of
Landlord to alter, remodel, decorate, clean or improve the demised premises or
the Building and no representation respecting the condition of the demised
premises or the Building have been made by Landlord to Tenant, unless the same
is contained herein, or made a part hereof, or contained in a written document
signed by Landlord or its Agent. This Lease does not grant any rights to light
or air over property.

         5.     INTENTIONALLY OMITTED.

                                       5
<PAGE>
         6. USE OF PREMISES. Tenant shall occupy and use the demised premises
during the term for the purpose above specified and none other:

                (a) Tenant will not make or permit to be made any use of the
         demised premises which, directly or indirectly is forbidden by public
         law, ordinance or governmental regulation or which may be dangerous to
         persons or property, or which may invalidate or increase the premium
         cost of any policy of insurance carried on the Building or covering its
         operations and Tenant shall not do, or permit to be done, any act or
         thing upon the demised premises which will be in conflict with fire
         insurance policies covering the Building of which the demised premises
         form a part. Tenant, as its sole expense shall comply with all rules,
         regulations or requirements of the Illinois Inspection and Rating
         Bureau, or any other similar body, and shall not do, or permit anything
         to be done upon said premises, or bring or keep anything thereon in
         violation of rules, regulations or requirements of the Fire Department,
         Illinois Inspection and Rating Bureau. Fire Insurance Rating
         Organization or other authority having jurisdiction and then only in
         such quantity and manner of storage as not to increase the rate of fire
         insurance applicable to the Building;

                (b) any sign installed in the demised premises shall be
         installed at Tenant's cost and if visible from outside of the demised
         premises in such manner, character and style as Landlord may approve in
         writing;

                (c) Tenant shall not advertise the business, profession or
         activities of Tenant conducted in the Building in any manner which
         violates the letter of spirit of any code of ethics adopted by any
         recognized association or organization pertaining to such business,
         profession or activities and shall never use any picture or likeness of
         the Building in any circulars, notices, advertisements or
         correspondence without Landlord's express consent in writing, which
         consent shall not be unreasonably withheld;

                (d) Tenant shall not obstruct, or use for storage, or for any
         purpose other than ingress and egress, the sidewalks, entrances,
         passages, courts, corridors, vestibules, halls, elevators or stairways
         of the Building;

                (e) no bicycle or other vehicle and no dog or other animal or
         bird shall be brought or permitted to be in the Building or any part
         thereof;

                (f) no noise, odor or litter, whether caused by Tenant, Tenant's
         customers, clients, invitees or guests, which is objectionable to
         Landlord or other occupants of the Building, shall emanate from the
         demised premises. Tenants shall not: I) create or maintain a nuisance
         on the demised premises, or ii) disturb, solicit or canvass any
         occupant of the Building, or iii) do any act tending to injure the
         reputation of the Building;

                (g) Tenant shall not install any musical instrument or equipment
         in the Building, or any antennas, aerial wires or other equipment
         inside or outside the Building, without, in each and every instance,
         obtaining prior approval in writing by Landlord. The use thereof, if
         permitted, shall be subject to control by Landlord to the end that
         others shall not be disturbed or annoyed, provided however, the Tenant
         shall have the right at its sole expense to install and maintain a
         receiving and transmitting facility (antennae), including connections
         to the demised premises, in a location and manner and of a size and
         weight approved by Landlord, on the roof of the Building if Tenant
         first obtains all necessary permits and licenses from the City of
         Chicago and any other governmental agency having jurisdiction.

                (h) Tenant shall not waste water by tying, wedging or otherwise
         fastening open any faucet;

                (i) except as provided in Section 39, no additional locks or
         similar devices shall be attached to any door. No keys for any door
         other than those provided by Landlord shall be made. If more than two
         keys for one lock are desired by Tenant, Landlord may provide the same
         upon payment by Tenant. Upon termination of this Lease or of Tenant's
         possession, Tenant shall surrender all keys to the demised premises and
         shall make known to Landlord the explanation of all combination locks
         on safes, cabinets and vaults;

                (j) Tenant assumes full responsibility for: (i) protecting the
         premises from theft, robbery and pilferage, (ii) keeping the premises
         secure, and (iii) locking the doors in and to the demised premises. Any
         damage resulting from neglect of this clause shall be paid for by
         Tenant. All property belonging to Tenant, or any person in the
         premises, which is in the Building or the premises, shall be there at
         the risk of Tenant or other person only, and Landlord, its
         beneficiaries. Owner and Owner's partners and their respective agents
         and employees shall not be liable for damage thereto or theft or
         misappropriation thereof. Tenant shall indemnify and hold Landlord, its
         beneficiaries, Owner and Owner's partners and their respective agents
         and employees harmless from any claims arising out of the above,
         including subrogation claims by Tenant's insurance carrier, except that
         nothing contained herein shall require Tenant to release, indemnify, or
         waive claims against Landlord or Owner for liability caused by the
         negligence of Landlord or Owner of their respective agents, servants or
         employees;

                                       6
<PAGE>

                (k) if Tenant desires telegraphic, telephonic, burglar alarm or
         signal service, Landlord will, upon request, direct where and how
         connections and all wiring for such service shall be introduced and
         run. Without such directions, no boring, cutting or installation of
         wires or cables is permitted. Landlord represents that the Building
         will contain facility which will permit Tenant to pull television cable
         for an in-house television system throughout the Building and for
         connection to the Trading Floor; provided however, that such facilities
         must, in Landlord's reasonable judgment fit and be compatible with the
         designed core structure of the Building. Landlord agrees that two (2)
         five-inch (5") cables shall fit and be comparable with the designed
         core structure of the Building;

                (l) shades, draperies or other form of inside window covering
         must be of such shape, color and material as approved by Landlord;

                (m) Tenant shall not overload any floor. Safes, furniture and
         all large articles shall be brought through the Building and into the
         demised premises at such times and in such manner as Landlord shall
         direct and at Tenant's sole risk and responsibility. Tenant shall list
         all furniture, equipment and similar articles to be removed from the
         Building, and the list must be approved at the Office of the Building
         or by a designated person before Building employees will permit any
         article to be removed;

                (n) unless Landlord gives advance written consent in each and
         every instance. Tenant shall not install or operate any steam or
         internal combustion engine, boiler, machinery, refrigerating or heating
         device or air-conditioning apparatus in or about the demised premises,
         or carry on any mechanical business therein, or used the demised
         premises for housing accommodations or lodging or sleeping purposes, or
         do any cooking therein or install or permit the installation of any
         vending machines, or use any illumination other than electric light, or
         use or permit to be brought into the Building any inflammable oils or
         fluids such as gasoline, kerosene, naphtha and benzene, or any
         explosive or other articles hazardous to persons or property. Tenant is
         hereby granted permission to install kitchen facilities for use by
         Tenant's employees and invitees only. The expense of such kitchen
         facilities shall be the sole responsibility of Tenant and shall include
         among other costs: i) required venting and flues, and ii) an exhaust
         stack tap-in charge based upon Tenant's proportionate C.F.M. usage;

                (o) Tenant shall not place or allow anything to be against or
         near the glass of partitions or doors of the demised premises which may
         diminish the light in, or be unsightly from, public halls or corridors;

                (p) Tenant shall not install in the demised premises any
         equipment which uses a substantial amount of electricity without the
         advance written consent of Landlord. Tenant shall ascertain from
         Landlord the maximum amount of electrical current which can safely be
         used in the demised premises, taking into account the capacity of the
         electric wiring in the Building and the demised premises and the needs
         of other tenants in the Building and shall not use more than such safe
         capacity. Landlord's consent to the installation of electric equipment
         shall not relieve Tenant from the obligation not to use more
         electricity than such safe capacity;

                (q) Tenant may not install carpet padding or carpet by means of
         a mastic without Landlord's approval.

                (r) Tenant shall not conduct any auction, fire or "going out of
         business", or bankruptcy sales in or from the demised premises;

                (s) Tenant shall lower and adjust the venetian blinds on the
         windows in the premises if such lowering and adjustment reduces the sun
         load;

                (t) in addition to all other liabilities for breach of any
         covenant of this Section 6, Tenant shall pay to Landlord all damages
         caused by such breach and shall also pay to Landlord as additional Base
         Rent an amount equal to any increase in insurance premium or premium
         caused by such breach. Any violation of this Section 6 may be
         restrained by injunction. Tenant shall be liable to Landlord for all
         damages resulting from violation of any of the provisions of this
         Section 6. Landlord shall have the right to make such reasonable rules
         and regulations as Landlord or its agent may from time to time adopt on
         such reasonable notice to be given as Landlord may elect.** Nothing in
         this Lease shall be construed to impose Landlord any duty or obligation
         to enforce provisions of this Section 6 or any rules and regulations
         hereafter adopted, or the terms, covenants or conditions of any other
         lease as against any other tenant, and Landlord shall not be liable to
         Tenant for violation of the same by any other tenant, its servants,
         employees, agents, visitors or licensees.

         7. CARE AND MAINTENANCE. Subject to the provisions of Section 10,
Tenant shall, at Tenant's own expense, keep the demised premises (excepting
structural elements of the Building, the Building's mechanical or HVAC systems
or exterior glass) in good order, condition and repair during the term*** If
Tenant does not make repairs promptly and adequately, Landlord, after serving
notice on Tenant and Tenant's failure to make such repair within ten (10) days,
may, but need not, make repairs, and Tenant shall promptly pay the cost
thereof,* Tenant shall pay Landlord for overtime and for any other expense
incurred in the event repairs, alterations, decorating or other work in the
demised premises are not made during ordinary business hours at Tenant's
request.

* provided however, such notice and grace period shall not be necessary in cases
  of emergencies as determined by Landlord in the exercise of its sole
  discretion.

** Landlord will make reasonable efforts to apply rules equally to all tenants.
   In the event a conflict between rules and this Lease occurs, the Lease shall
   control.

*** excepting repairs required as a result of Landlord's conduct or the conduct
    of another tenant.

                                       7
<PAGE>

         8.        ALTERATIONS AND CONSTRUCTION.

                (a) Tenant may not do any work ("Work") in the demised premises
         such as, but not limited to, erecting partitions, making alterations or
         additions, nailing, boring or screwing into the ceilings, walls or
         floors, without the prior written consent of Landlord in each and every
         instance provided however, that a cosmetic alteration such as painting,
         decorating, [unreadable text] or hanging pictures does not require the
         approval of Landlord [unreadable text] it is visible from the exterior
         of the demised premises or the Building and provided further,
         Landlord's consent shall not be unreasonably withheld in cases of other
         alterations not visible from the exterior of the premises or the
         Building. Under such circumstances however, compliance with this
         Section 8 is required. The decision of Landlord to refuse such consent
         unless otherwise provided shall be conclusive, in order to obtain such
         consent. Tenant shall furnish Landlord (i) plans and specifications for
         the Work (which Tenant warrants is in conformance with all applicable
         laws and is consistent in all respects with the aesthetics, structural
         and mechanical systems of the Building), (ii) names and addresses of
         contractors ("Contractors") and subcontractors ("Subcontractors"),
         (iii) copies of contracts with Contractors and Subcontractors which
         shall provide, among other things, that no charges, amendments, extras
         or additional work are permitted without the consent of Landlord, and
         (iv) affidavits from engineers acceptable to Landlord stating that the
         Work will not in any way adversely affect any mechanical system in the
         Building, such as, but not limited to, the heating, ventilating, air-
         conditioning or electrical systems. Landlord reserves the right to deny
         any Contractor or Subcontractor entry to the Building but Landlord's
         failure to exercise this right shall not be deemed an approval of
         either the financial stability or quality of workmanship of any such
         Contractor of Subcontractor.

                (b) If Landlord grants such consent, all Work shall be performed
         in a workmanlike manner (and materials furnished shall be of a like
         quality to those in the Building) and either by or under the
         supervision of Landlord but at the sole expense of Tenant. Subsequent
         to the granting of such consent but before the commencement of the Work
         or delivery of any materials onto the demised premises or into the
         Building, Tenant shall furnish Landlord (i) necessary permits, (ii)
         sworn Contractor affidavits listing all subcontracts with suppliers of
         materials and/or labor, with whom Contractors have contractual
         relations for the Work, and setting forth a summary of such contractual
         relationships, (iii) Subcontractor affidavits, (iv)*, (v) certificates
         of insurance form all Contractors and Subcontractors performing labor
         or furnishing materials, insuring against any and all claims, costs,
         damages, liabilities and expenses which may arise in connection with
         the Work, and (vi) such other documents as may be reasonably requested
         by Landlord. The certificates of insurance required must evidence
         coverage in amounts and from companies satisfactory to Landlord and may
         be cancelable only with ten (10) days advance notice to Landlord. If
         Landlord consents or supervises, such shall not be deemed a warranty as
         to the adequacy of the design or workmanship or quality of the
         materials and Landlord hereby disavows any responsibility and/or
         liability for such. Additionally, under no circumstances shall Landlord
         have any responsibility to repair or maintain any portion of the Work
         which either does not function or ceases to function.

                (c) During construction of the Work, upon receipt by Landlord of
         waivers, mechanics' liens and percentage completion certificates from
         Tenant, Contractors and the architect, Landlord shall disburse the
         funds deposited pursuant to Paragraph 8(b) (iv) to the joint order of
         Tenant and Contractors.

                (d) Upon completion of the Work, and prior to final payment,
         Tenant shall obtain the written approval of Landlord (which shall not
         be unreasonably withheld) for the quality of the Work and furnish
         Landlord with (i) Tenant, Contractors, and architectural completion
         affidavits, (ii) full and final waivers of lien, (iii) receipted bills
         covering all labor and materials expended and used, (iv) other
         appropriate documents evidencing completion of the Work, and (v)
         as-built plans of the Work.

                (e) Tenant shall pay Landlord for use of elevators (except the
         use of Tenant's elevator) and/or hoists, during the Work, at the same
         rate being charged to other similar users. Tenant shall cooperate with
         Landlord in scheduling such use.

                (f) If the Work is being done near the commencement of the Lease
         term, Tenant agrees to commence payment of Base Rent and Rent
         Adjustments upon the date and in the manner provided in this Lease
         notwithstanding any delay in completing the Work or the demised
         premises which may result from the performance of the Work by Tenant or
         its Contractors.

                (g) Tenant shall procure, or cause to be procured, and pay for
         all permits, licenses, approvals, certificates and authorizations
         necessary to the prosecution and completion of the Work. All Work shall
         be done in strict accordance with all laws, ordinances, rules,
         regulations and requirements of the Board of Underwriters and all
         Municipal, State, Federal and other authorities having jurisdiction.
         Where drawings and specifications conflict with the law, the law is to
         be followed. Tenant shall promptly notify the respective departments or
         official bodies when the Work is ready for inspection and shall, at
         once, do all work required to remove any violations or to comply with
         such inspections, without additional charge to Landlord. Tenant shall
         perform, or cause to be performed, all work necessary to obtain
         approvals from authorities mentioned above without additional cost to
         Landlord.

                (h) Tenant agrees to reimburse Landlord for all sums expended
         for examination and approval of the architectural and mechanical plans
         and specifications.

* 1. for Tenant and credit-worthy Members (to be determined solely by Landlord)
  indemnification in the form of an irrevocable Letter of Credit (drafted solely
  as Landlord determines) in a sum equal to the total value of the Work, and

  2. for all other Members, indemnification in the form of cash in a sum equal
  to the total value of the Work.

                                       8
<PAGE>

                (i) Tenant agrees that the Work shall be performed so as not to
cause or create any jurisdictional or other labor disputes, and in the event
such disputes occur. Tenant shall immediately do whatever is necessary to
resolve such disputes, at no expense to Landlord.

                (j) Tenant hereby agrees to hold Landlord, its beneficiaries,
Owner and Owner's partners and their respective agents and employees harmless
from any and all liabilities of every kind and description, including reasonable
attorney's fees which may arise out of or be connected in any way with the Work.
Any mechanic's lien (or any notice preliminary to lien) filed against the
demised premises, or the Real Property, for the Work or materials claimed to
have been furnished to Tenant shall be discharged of record (or paid if a notice
be served) by Tenant within ten (10) days after filing (or service) at the
expense of Tenant provided however, that if Tenant has on deposit with Landlord
one hundred fifty percent (150%) of the lien, in cash and otherwise holds
Landlord harmless and indemnifies Landlord, tenant may contest the lien.

                (k) All additions, decorations, fixtures, hardware, non-trade
fixtures and all improvements, temporary or permanent, in or upon the demised
premises, whether placed there by Tenant or Landlord, shall, unless Landlord
requests their removal, become the property of Landlord and shall remain upon
the demised premises at the termination of this Lease by lapse of time or
otherwise without compensation, allowance or credit to Tenant. If, upon the
request of Landlord, Tenant does not remove said additions, decorations,
fixtures, hardware, non-trade fixtures and improvements, Landlord may remove
them upon the expiration or termination of this Lease, provided however, that
Tenant shall be responsible for the restoration of the premises to the condition
in which they existed at the commencement date of this Lease, reasonable wear
and tear and damage by fire or other casualty excepted.

         9. ACCESS TO PREMISES. Tenant shall permit Landlord to erect, use and
maintain pipes, ducts, wiring and conduits in and through the demised premises.
Landlord or Landlord's agents shall have the right to enter upon the premises,
to inspect the same, to perform janitorial and cleaning services and to make
such repairs, alterations, improvements or additions to the premises or the
Building as Landlord may deem necessary** and Landlord shall be allowed to take
all material into and upon said demised premises that may be required therefore
without the same constituting an eviction of Tenant in whole or in part and the
Base Rent and/or Rent Adjustments shall in no wise abate (except as provided in
Section 10) while said repairs, alternations, improvements, or additions are
being made, by reason of loss or interruption of business of Tenant, or
otherwise,* If Tenant shall not be personally present to open and permit an
entry into said demised premises, at any time, when for any reason an entry
therein shall be necessary or permissible. Landlord or Landlord's agents may
enter the same by a master key, or may forcibly enter the same, without
rendering Landlord or such agents liable therefore (if during such entry
Landlord or Landlord's agents shall accord reasonable care to Tenant's
property), and without in any manner affecting the obligations and covenants of
this Lease. Nothing herein contained, however, shall be deemed or construed to
impose upon Landlord any obligations, responsibility or liability whatsoever,
for the care, supervision or repair of the Building or any part thereof, other
than as herein provided. Landlord shall also have the right at any time, without
the same constituting an actual or constructive eviction and without incurring
any liability to Tenant therefore, to change the arrangement and/or location of
entrance or passageways, doors and doorways, and corridors, elevators, stairs,
toilets or other public parts of the Building, and to close entrances, doors,
corridors, elevators or other facilities. Landlord shall not be liable to Tenant
for any expense, injury, loss or damage resulting from work done in or upon, or
the use of, any adjacent or nearby building, land, street or alley. ***

         10. UNTENANTABILITY. If the demised premises or the Building are made
untenantable by fire or other casualty and if the Trading Floor has not been
made untenantable or if it has been made untenantable and owner of Trading Floor
contracts for and commences the Trading Floor's reconstruction, Landlord shall
proceed with all due diligence to repair, restore or rehabilitation the Building
or the demised premises at Landlord's expense in which event this Lease shall
not terminate. If however, the demised premises or the Building, and the Trading
Floor, are made untenantable by fire or other casualty and if owner of Trading
Floor does not so contract or commence such reconstruction of the Trading Floor,
Landlord may elect:

                (a) to terminate this Lease as of the date of the fire or
         casualty by notice to Tenant within one-hundred fifty (150) days after
         date, or

                (b) proceed with all due diligence to repair, restore or
         rehabilitate the Building or the demised premises at Landlord's
         expense, in which latter event this Lease shall not terminate, ****

                In the event the Lease is not terminated pursuant to this
provision, Base Rent and Rent Adjustments shall abate on a per diem basis during
the period of untenantability. In the event of the termination of this Lease
pursuant to this section, Base Rent and Rent Adjustments shall be apportioned on
a per diem basis and paid to the date of the fire of other casualty. In the
event that the demised premises are partially damaged by fire or other casualty
but not made wholly untenantable, then Landlord shall, except during the last
year of the term hereof proceed with all due diligence to repair and restore the
demised premises and the Base Rent and Rent Adjustments shall abate in
proportion to the untenantability of the demised premises during the period of

* provided however, that excepting emergency situations, Landlord shall exercise
  reasonable efforts not to interfere with the conduct of Tenant's business on
  the premises. In the event Landlord's access to the premises or any part
  thereof pursuant to this Section 9 causes the demised premises or any part
  thereof to be rendered untenantable or inaccessible excepting untenantability
  or inaccessibility resulting from fire or other casualty as stated in Section
  10) by Tenant for more than thirty (30) consecutive business days, then Base
  Rent and Rent Adjustments shall abate on a per diem basis for each day after
  such thirty (30) day period during which the premises or any part thereof are
  not tenantable or accessible prorated, however, in proportion to the portion
  of the demised premises which are so rendered untenantable or inaccessible to
  the total demised premises.

** provided however, that if Landlord decreases the size of the demised
   premises, Base Rent and other appropriate items shall be appropriately
   reduced

*** Nothing contained herein shall require Tenant to release, indemnify, or
    waive claims against Landlord or Owner for liability caused by the
    negligence of Landlord or Owner or their respective agents, servants or
    employees.

**** provided however, if Landlord fails to repair, restore or rehabilitate
     demised premises within 270 days after the aforementioned 150 days, the
     Tenant shall have the right to terminate this Lease as of the date of said
     fire or casualty by serving notice on Landlord within ten (10) days after
     if Landlord fails to so repair, restore or rehabilitate within the 270 day
     period and such failure is the result of Force Majeure or Acts of Tenant
     the 270 day period shall be deemed extended for a period of time equal to
     the delay.

                                       9
<PAGE>

untenantability. Notwithstanding anything hereinbefore contained in this Section
10 or in Section 10A, if a portion of the demised premises are made untenantable
as aforesaid during the last year of the term hereof exercised [unreadable text]
renewal option contain in Section 27 or its rights under Section 30. Landlord or
Tenant shall have the right to terminate this Lease as of the date of the fire
or other casualty by giving written notice thereof to the other within thirty
(30) days after the date of fire or other casualty, in which event the Base Rent
and Rent Adjustments shall be apportioned on a per diem basis and paid to the
date of such fire or other casualty.**

         11. SUBROGATION. The parties hereto agree to use good faith efforts to
have any and all fire, extended coverage or any and all material damage
insurance which maybe carried endorsed with the following subrogation clause:
"This insurance shall not be invalidated should the insured waive in writing
prior to a loss any or all right of recovery against any party for loss
occurring to the property described herein"; and each party hereto hereby waives
all claims for recovery from the other party for any loss or damage to any of
its property insured under valid and collectible insurance policies to the
extent of any recovery, collected under such insurance, subject to the
limitation that this waiver shall apply only when it is either permitted or, by
the use of such good faith efforts could have been so permitted by the
applicable policy of insurance.

         12. EMINENT DOMAIN. If a substantial portion of the Building, or a
substantial part of the demised premises, shall be lawfully taken or condemned
for any public or quasi-public use or purpose, or conveyed under threat of such
condemnation, the term of this Lease shall end upon, and not before, the date of
the taking of possession by the condemning authority, and without apportionment
of the award. Current rent shall be apportioned as of the date of such
termination. If any part of the Building, shall be so taken or condemned, or if
the grade of any street or alley adjacent to the Building is changed by any
competent authority and such taking or change of grade makes it necessary or
desirable to demolish, substantially remodel, or restore the Building, Landlord
shall have the right to cancel this Lease upon not less than ninety (90) 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 the right of
cancellation, and Tenant may share in the condemnation award or in any judgment
for damages caused by the change of grade, but only to the extent that
unamortized portion of its leasehold improvements. Tenant may proceed
independently in such proceedings if its chosen. If an insubstantial portion of
the premises shall be lawfully taken or condemned or conveyed under threat of
condemnation so that the premises can be used by Tenant for the purposes set
forth in this Lease, and this Lease is not terminated by Landlord, Landlord
shall repair the premises, and the Lease shall be amended to reduce Tenant's
Proportion and Base Rent in the proportion of the amount taken.

         ** Section 10A, see page 42.

         13.    ASSIGNMENT - SUBLETTING.

                (a) Tenant may sublet the demised premises or any part thereof
         but Tenant shall not, without Landlord's prior written consent:

                      (i) assign (other than to a successor* of Tenant under
                which circumstances Tenant's liability for the demised premises
                shall in no way be deemed modified, abrogated or amended),
                hypothecate, mortgage, encumber, or convey this Lease;

                      (ii) sublet to Members subsequent to the first ten (10)
                years of the Lease term; or (iii) otherwise permit the use or
                occupancy of the premises or any part thereof by anyone other
                than Tenant.

                (b)    If Tenant sublets the demised premises;

                      (i) the terms and conditions of this Lease, including
                among other things, the use provisions and Tenant's liability
                for the demised premises shall in no way be deemed modified,
                abrogated or amended.

                      (ii) Tenant shall pay Landlord as additional Base Rent,
                sixty percent (60%) of any excess rent (together with
                escalation) payable to and collected by Tenant under the
                sublease over the Base Rent plus Rent Adjustments payable to
                Landlord under this Lease, except that notwithstanding any other
                provision of this Lease, there shall be no abatement or
                reduction of Base Rent or Rent Adjustments as a result of
                amounts payable pursuant to clause (ii) of this Section 13(b).

* ("successor" means a successor exchange which succeeds to all or substantially
  all of the assets and goodwill of Tenant.)

                                       10
<PAGE>

Such excess rent shall first be reduced by sixty percent (60%) of the following:

                             1.      subletting commissions;
                             2.      advertising or legal expenses involved in
                                     the subletting or in subsequently enforcing
                                     the terms thereof; and
                             3.      Tenant's actual expenditures for
                                     improvements it is required to make as a
                                     result of the sublease except that such
                                     improvement expense for purposes of this
                                     reduction may not exceed sixty per cent
                                     (60%) of ten percent (10%) of any projected
                                     excess rent together with escalation;

                      (iii) Landlord shall be provided a copy of the subletting
                documents within ten (10) days after their complete execution;

                      (iv) the subletting documents must contain default
                provisions similar to those contained in this Lease and in the
                event of a default under the sublease Tenant agrees to use
                reasonable efforts to promptly enforce such provisions.

         14. WAIVER OF CLAIMS AND INDEMNITY. To the extent permitted by law,
Tenant releases Landlord, its beneficiaries, Owner and Owner's partners and
their respective agents and servants from, and waives all claims for, damage to
person or property sustained by Tenant or any occupant of the Building or
premises resulting from the Building premises or any part of either or any
equipment or appurtenance becoming out of repair or resulting from any accident
in or about the Building, or resulting directly or indirectly from any act or
neglect of any tenant or occupant of the Building or of any other person,
including Landlord's agents and servants, but excluding the negligent acts or
omissions of Landlord or Owner or their respective agents, servants or
employees. This Section 14 shall apply especially, but not exclusively, to the
flooding of basements or other subsurface areas, and to damage caused by
refrigerators, sprinkling devices, air-conditioning apparatus, water, snow,
frost, steam, excessive heat or cold, falling plaster, broken glass, sewage,
gas, odors or noise, or the bursting or leaking of pipes or plumbing fixtures
and shall apply equally whether any such damage results from the act of Landlord
or the negligent acts or omissions of other tenants, occupants or servants in
the Building or of any other person, and whether such damage be caused or result
from any thing or circumstance above mentioned or referred to, or any other
thing or circumstance whether of a like nature or of a wholly different nature.
If any such damage, whether to the demised premises or to the Building or any
part thereof, or whether to Landlord or to other tenants in the Building,
results from any act or neglect of Tenant, its employees, agents, invitees or
customers. Tenant shall be liable therefor and Landlord may, at Landlord's
option, repair such damage and Tenant shall, upon demand by Landlord, reimburse
Landlord forthwith for the total cost of such repairs. Tenant shall not be
liable for any damage caused by its act or neglect if Landlord or a tenant has
recovered the full amount of the damage from insurance and the insurance company
has waived its right of subrogation against Tenant.*

                Except to the extent proceeds are paid from Landlord's
insurance, Tenant agrees to indemnify and save Landlord, its beneficiaries,
Owner and Owner's partners and their respective agents and employees harmless
against any and all claims, demands, costs and expenses, including reasonable
attorneys' fees for the defense thereof, arising from Tenant's occupation of the
demised premises 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
pursuant to the terms of this Lease, or from any act or negligence of Tenant,
its agents, servants, employees or invitees, in or about to demised premises. In
case of any action or proceeding brought against Landlord, its beneficiaries,
Owner and Owner's partners or their respective agents or employees by reason of
any such claim, upon notice from Landlord, Tenant covenants to defend such
action or proceeding by counsel reasonably satisfactory to Landlord. Nothing
contained in this section 14 shall require Tenant to release, indemnify, or
waive claims against Landlord or Owner for liability caused by the negligence of
Landlord or Owner or their respective agents, servants or employees.

* Nothing contained in this section 14 shall require Tenant to release,
  indemnify, or waive claims against Landlord or Owner for liability caused by
  the negligence of Landlord or Owner or their respective agents, servants or
  employees.

                                       11
<PAGE>

         15. MORTGAGE - GROUND LEASE. Landlord may execute and deliver a
mortgage or trust deed in the nature of mortgage, both sometimes hereinafter
referred to as "Mortgage" against the Building, the Real Property or any
interest therein, and may sell and lease back the underlying land on which the
Building is situated, except that the rights of Tenant under this Lease shall be
deemed superior to any mortgage or ground or underlying lease. If requested by
the mortgagee or trustee or by the lessor of any ground or underlying lease
(ground lessor), Tenant will either subordinate its interest in this Lease to
said Mortgage, or ground or underlying lease or make the interest in this Lease
superior, and will execute such agreement or agreements (including Exhibit "C")
as may be reasonably required by such mortgagee, trustee or ground lessor,
provided however, that as a condition precedent to Tenant's subordination, the
mortgagee (or trustee) or ground lessor shall first provide Tenant with a
Non-Disturbance and Attornment Agreement substantially in the form of attached
Exhibit "C".

                It is further agreed:

                (a) Should any Mortgage affecting the Building or the Real
         Property be foreclosed or if any ground or underlying lease be
         terminated:

                      (i) The liability of the mortgagee, trustee or purchaser
                at such foreclosure sale or the liability of a subsequent owner
                designated as Landlord under this Lease shall exist only so long
                as such trustee, mortgagee, purchaser or owner is the owner of
                the Building or Real Property and such liability shall not
                continue or survive after further transfer of ownership.

                      (ii) Upon request of the mortgagee or trustee, Tenant (if
                Tenant has received Exhibit "C") will attorn, as Tenant under
                this Lease, to the purchaser at any foreclosure sale thereunder,
                or if any ground or underlying lease be terminated for any
                reason, Tenant will attorn as tenant under this Lease to the
                ground lessor under the ground lease and will execute such
                instruments as may be necessary or appropriate to evidence such
                attornment.

                (b) This Lease may not be modified or amended so as to reduce
         the rent or shorten the term provided hereunder, or so as to adversely
         affect in any other respect to any material extent the rights of
         Landlord, nor shall this Lease be cancelled or surrendered, without the
         prior written consent, in each instance, of the ground lessor or the
         mortgagee.

                (c) To the extent this Section 15 is inconsistent with Exhibit
         "C", Exhibit "C" shall be deemed controlling.

                (d) At the request of any mortgagee, trustee or ground lessor,
         Tenant shall give notice of any default by Landlord hereunder to such
         mortgagee, trustee or ground lessor and such mortgagee, trustee or
         ground lessor shall have the right to cure such default within the
         applicable grace period provided herein, and provided further, that
         such grace period shall commence upon the giving of such notice by
         Tenant.

         16. CERTAIN RIGHTS RESERVED TO LANDLORD. Landlord reserves and may
exercise the following rights without affecting Tenant's obligations hereunder:

                (a) to change the name or street address of the Building,
         provided however, if Landlord proposes such a change, it shall be
         subject to Tenant's approval which shall not be unreasonably withheld,
         provided further however, that either a tenant in the Building or
         Landlord may refer to the Building or use the address of 366 West
         Monroe without Tenant's approval. Landlord shall install and maintain a
         "Chicago Mercantile Exchange Center" sign on the exterior of the
         Building;

                (b) to install and maintain a sign or signs on the exterior of
         the Building, provided however, such sign shall be subject to Tenant's
         approval which shall not be unreasonably withheld;

                (c) to have access for Landlord and the other tenants of the
         Building to any mail chutes located on the demised premises according
         to the rules of the United States Post Office;

                (d) to designate all sources furnishing coffee cart service used
         on the demised premises;

                (e) to decorate, remodel, repair, alter or otherwise prepare the
         demised premises for reoccupancy if Tenant vacates the demised premises
         prior to the expiration of the term;

                (f) to retain at all times pass keys to the demised premises;

                (g) to grant to anyone the exclusive right to conduct any
         particular business or undertaking in the Building.*

                (h) to exhibit the demised premises to others during the last 6
         months of the term;

                (i) to close the Building after regular working hours and on the
         legal holidays subject, however, to Tenant's right to admittance, under
         such reasonable regulations as Landlord may prescribe from time to
         time;

* provided however, that the granting of such exclusive rights shall not
  restrict or interfere with the conduct of Tenant's business on the demised
  premises and is subject to Section 35 of this Lease;

                                       12
<PAGE>

         which may include by way of example but not of limitation, that persons
         entering or leaving the Building identify themselves to a watchman by
         registration or otherwise and that said persons establish their right
         to enter or leave the Building;

                (j) to approve the weight, size and location of safes or other
         heavy equipment or articles, which articles may be moved in, about, or
         out of the Building or premises only at such times and such manner as
         Landlord shall direct and in all events, however, at Tenant's sole risk
         and responsibility, subject, in all events, to the provisions of
         Section 6(m).

                (k) to take any and all measures, including inspections,
         repairs, alterations, additions and improvements to the premises or to
         the Building, as may be necessary for the safety, protection or
         preservation of the premises or the Real Property or Landlord's
         interests, or as may be necessary or desirable in the operation of the
         Real Property.*

                Subject to Section 9, Landlord may enter upon the demised
         premises and may exercise any or all of the foregoing rights hereby
         reserved without being deemed guilty of an eviction or disturbance of
         Tenant's use or possession and without being liable in any manner to
         Tenant and without abatement of Base Rent or Rent Adjustments or
         affecting any of Tenant's obligations hereunder.

         17. HOLDING OVER. If Tenant retains possession of the demised premises
or any part thereof after the termination of the term or any extension thereof,
by lapse of time or otherwise on the first day of each month Tenant so retains
possession, Tenant shall pay Landlord the monthly Base Rent, plus Landlord's
estimate of Rent Adjustments, at double the rate payable for the month
immediately preceding said holding over computed on a per-month basis, for each
month or part thereof (without reduction for any such partial month) that Tenant
thus remains in possession, and in addition thereto, Tenant shall pay Landlord
all damages, consequential as well as direct, sustained by reason of Tenant's
retention of possession. The provisions of this paragraph do not exclude
Landlord's right of re-entry or any other right hereunder.

         18. LANDLORD'S REMEDIES. All rights and remedies of Landlord herein
enumerated shall be cumulative, and none shall exclude any other right or remedy
allowed by Law.

                (a) To the extent permitted by law, if, at any time during the
         term of this lease (i) Tenant who is then the holder of this Lease
         shall file in any court a petition in bankruptcy or insolvency or for
         reorganization within the meaning of Chapter X or XII of the Bankruptcy
         Act of 1898 and/or Title 11, U.S. Code Bankruptcy Reform Act of 1978,
         or for arrangement within the meaning of Chapter XI of said Bankruptcy
         or Reform Act (or for reorganization or arrangement under any future
         Bankruptcy or Reform Act for the same or similar relief), or for the
         appointment of a receiver or trustee of all or a portion of Tenant's
         property, or (ii) an involuntary petition of the kind referred to in
         subdivision (i) of this sub-paragraph, shall be filed against Tenant,
         and such petition shall not be vacated or withdrawn within one hundred
         twenty (120) days after the date of filing thereof, or (iii) if Tenant
         shall make an assignment for the benefit of creditors, or (iv) if
         Tenant shall be adjudicated a bankrupt, or (v) a receiver shall be
         appointed for the property of Tenant by order of a court of competent
         jurisdiction (except where such receiver shall be appointed in an
         involuntary proceeding, if he shall not be withdrawn within one hundred
         twenty (120) days from the date of his appointment), then and in any
         such event Landlord may, if Landlord so elects but not otherwise, and
         with or without notice of such election, and with or without entry or
         other action by Landlord, forthwith terminate this Lease, and
         notwithstanding any other provisions of this Lease, Landlord shall
         forthwith upon such termination be entitled to recover damages in an
         amount equal to the then present value of Base Rent plus Rent
         Adjustments.

                (b) If Tenant defaults in the payment of Base Rent, Rend
         Adjustment Deposits or Rent Adjustments and Tenant does not cure the
         default within twenty (20 days after written demand for payment of such
         Base Rent, Rent Adjustment Deposits or Rent Adjustments or if Tenant
         defaults in the prompt and full performance of any other provisions of
         this Lease, and Tenant does not cure the default within forty-five (45)
         days after written demand by Landlord that the default be cured (unless
         the default involves a hazardous condition, which shall be cured
         forthwith) or if the leasehold interest of Tenant be levied upon under
         execution or be attached by process of law, or if Tenant makes an
         assignment for the benefit of creditors or admits its inability to pay
         its debts, or if a receiver be appointed for any property of Tenant, or
         if Tenant abandons the premises, then and in any such event Landlord
         may, if Landlord so elects but not otherwise, and with or without
         notice of such election, and

* Material alterations to the premises (excepting alterations to the mechanical
  systems, HVAC or structure of the Building) not necessary to protect the
  Building or the health or safety of its occupants are subject to Tenant's
  approval which shall not be unreasonably withheld.

                                       13
<PAGE>

         with or without any demand whatsoever, either forthwith terminate this
         Lease and Tenant's right to possession of the premises or, without
         terminating this Lease, forthwith terminate Tenant's right to
         possession of the premises*

                (c) Upon any termination of this Lease, whether by lapse of time
         or otherwise, or upon any termination of Tenant's right to possession
         without termination of the Lease, Tenant shall surrender possession and
         vacate the premises immediately, and deliver possession thereof to
         Landlord, and hereby grants to Landlord full and free license to enter
         into and upon the premises in such event with process of law and to
         repossess Landlord of the premises as of Landlord's former estate 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, without
         being deemed in any manner guilty of trespass, eviction or forcible
         entry or detainer, and without relinquishing Landlord's rights to Base
         Rent or Rent Adjustments or any other right given to Landlord hereunder
         or by operation of law.

                (d) Landlord may elect to terminate Tenant's right to possession
         only, without terminating the Lease, if Tenant fails to occupy or take
         possession of the premises or abandons or vacates the premises or
         otherwise entitles Landlord so to elect. Further, landlord may elect to
         enter into the premises, remove Tenant' signs and other evidences of
         tenancy, and take and hold possession thereof as in Paragraph (c) of
         this Section 18 provided, without such entry and possession terminating
         this Lease or releasing Tenant, in whole or in part, from Tenant's
         obligation to pay the Base Rent or Rent Adjustments hereunder for the
         full term, and in any such case Tenant shall pay forthwith to Landlord,
         if Landlord so elects, a sum equal to the entire amount of Base Rent
         and Rent Adjustments for the residue of the stated term plus any other
         sums then due hereunder. Upon and after entry into possession without
         termination of the Lease, Landlord may, but need not, relet the
         premises or any part thereof for the account of Tenant to any person,
         firm or corporation other than Tenant for such Base Rent, for such time
         and upon such terms as Landlord in Landlord's sole discretion shall
         determine, and Landlord shall not be required to accept any tenant
         offered by Tenant or to observe any instructions given by Tenant about
         such reletting. In any such case, Landlord may make reasonable repairs,
         alterations and additions in or to the premises, and redecorate the
         same to the extent deemed by Landlord necessary or desirable, and
         Tenant shall, upon demand, pay the cost thereof, together with
         Landlord's expenses of the reletting. If the consideration collected by
         Landlord upon any such reletting for Tenant's account is not sufficient
         to pay monthly the full amount of the Base Rent and Rent Adjustments
         reserved in this Lease, together with the costs of repairs,
         alterations, additions, redecorating and Landlord's expenses, Tenant
         shall pay to Landlord the amount of each monthly deficiency upon
         demand.

                (f) Any and all property which may be removed from the premises
         by Landlord pursuant to the authority of the Lease or of 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 to Landlord, upon demand, any and all expense
         incurred in such removal and all storage charges against such property
         so long as the same shall be in Landlord's possession or under
         Landlord's control. Any such property of Tenant not retaken from
         storage by Tenant at the end of the term, however terminated, shall be
         conclusively presumed to have been conveyed by Tenant to Landlord under
         this Lease as a bill of sale without any further payment or credit by
         Landlord to Tenant.

* provided however, if Tenant defaults in any provision of this Lease other than
  the payment of Base Rent or Rent Adjustments, which shall be governed as
  stated, or other than a default which involves a hazardous condition, which
  shall be cured forthwith, and if Tenant, within the 45-day period referred to
  above, gives Landlord evidence which is satisfactory, in the sole discretion
  of Landlord, that Tenant is diligently pursuing a course which will remedy the
  default which is subject of the notice, such default shall be deemed remedied,
  but provided further, that in the event, after 90 days elapse from the date
  Landlord determines that the evidence provided by Tenant is satisfactory, if
  such be the case, such default be not cured, Landlord shall thereupon again
  have the right to serve notice of default as provided in this Section 18(b),
  and under such circumstances Tenant shall not have the right to evidence
  diligent remedying of the default to avoid its consequences.

                                       14
<PAGE>

                (g) Tenant hereby grants to Landlord a first lien upon the
         interest of Tenant under this Lease to secure the payment of moneys due
         under this Lease, which lien may be enforced in equity and Landlord
         shall be entitled as a matter of right to have a receiver appointed to
         take possession of the demised premises and relet the same under order
         of court.

                (h) Landlord Tenant shall pay upon demand all the other's
         reasonable costs, charges and expenses, including the reasonable fees
         of counsel, agents and others retained or incurred in enforcing each
         other's obligations hereunder or incurred by Landlord or Tenant in any
         litigation, negotiation or transaction in which Landlord or Tenant
         causes the other without the other's fault, to become involved or
         concerned if the enforcing party prevails.

         19. DEFAULT UNDER OTHER LEASE. If the term of any lease, other than
this Lease, made by Tenant for any demised premises in the Building shall be
terminated or terminable after the making of this Lease because of any default
by Tenant under such other lease, such fact shall empower Landlord, at
Landlord's sole option, to terminate this Lease by notice to Tenant.

         20. SURRENDER OF POSSESSION. Upon the expiration or other termination
of the term of this Lease, or Tenant's right to possession hereunder, Tenant
shall quit and surrender to Landlord the premises, broom clean, in good order
and condition, ordinary wear excepted, and Tenant shall remove all of its
property. If Tenant does not remove its property of every kind and description
from the demised premises prior to the end of the term, however ended, Tenant
shall be conclusively presumed to have conveyed the same to Landlord under this
Lease as a bill of sale without further payment or credit by Landlord to Tenant
and Landlord may remove the same and Tenant shall pay the cost of such removal
to Landlord upon demand. Tenant's obligation to observe or perform this covenant
shall survive the expiration or other termination of the term of this Lease.

         21. NOTICES. Notices shall be in writing.

                (a)   Notices shall be effectively served by Landlord upon
                      Tenant in the following manner: (i) By forwarding through
                      Certified or Registered Mail, postage prepaid, to Tenant
                      at the premises,

                            Attention:       the President
                            with a copy to:  Chairman of the Board
                                             Chicago Mercantile Exchange

                            and with a copy to:  Goldberg, Kohn, Bell,
                                                 Black and Rosenbloom
                                                 Attorneys at Law
                                                 Mid-Continental Plaza
                                                 55 E. Monroe St., Suite 3950
                                                 Chicago, Illinois  60603

                in which case the time of mailing shall be the time of notice;

                (b) Notices shall be effectively served by Tenant upon Landlord
         when addressed to Landlord and served either;

                      (i)  Upon an officer of Landlord; or

                      (ii) Certified or Registered Mail, postage prepaid, to
                Landlord in case of JMB/MS Management Co., Suite 1200, 111 East
                Wacker Drive, Chicago, Illinois 60601, Attention: Legal
                Department or if notified of another address by Landlord at such
                latter address.

                (c) Notice shall be effectively served by Tenant upon any
         mortgagee, trustee or ground lessor by forwarding such notice by
         certified or registered mail, postage prepaid to such mortgagee,
         trustee or ground lessor at its address as set forth in its request for
         notices pursuant to Section 15, or as Tenant is subsequently advised by
         such mortgagee, trustee or ground lessor in writing.

                                       15
<PAGE>

          24.   MISCELLANEOUS.

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

                (b) No waiver of any default of Tenant or Landlord hereunder
          shall be implied from any omission by Landlord or Tenant to take any
          action on account of such default if such default persists or be
          repeated, and no express waiver shall affect any default other than
          the default specified in the express waiver and that only for the time
          and to the extent therein state.

                (c) The words "Landlord" and "Tenant" wherever used in this
          Lease shall be construed to mean plural where necessary, and the
          necessary grammatical changes required to make the provisions hereof
          apply either to corporations or individuals, men or women, shall in
          all cases be assumed as though in each case fully expressed.

                (d) Each provision hereof shall extend to and shall, as the case
          may require, bind and inure to benefit of Landlord and Tenant and
          their respective heirs, legal representatives, successors and assigns
          in the event this Lease has been assigned with the express written
          consent of Landlord or has been permitted herein.

                (e) Submission of this instrument for examination does not
          constitute a reservation of or option for the premises. The instrument
          does not become effective as a lease or otherwise until execution and
          delivery by both Landlord and Tenant.

                (f) All amounts (unless otherwise provided herein, and other
          than the Base Rent, Rent Adjustment Deposits and Rent Adjustments,
          which shall be due as hereinbefore provided) owed by Tenant to
          Landlord hereunder shall be deemed additional Base Rent and be paid
          within ten (10) days from the date Landlord renders statements of
          account therefor. All such amounts (including Base Rent, Rent
          Adjustment Deposit and Rent Adjustments) shall bear interest from
          twenty (20) days after the date due until the date paid at the rate of
          2% above the prime rate of interest in effect at the First National
          Bank of Chicago on the date of payment, or at the maximum legal rate
          of interest, whichever is lower.

                (g) All riders attached to this Lease and initiated by Landlord
          and Tenant are hereby made a part of this Lease as though inserted in
          this Lease.

                (h) The headings of sections are for convenience only and do not
          limit or construe the contents of the sections.

                (i) If Tenant shall occupy the premises prior to the beginning
          of the term of this Lease with Landlord's consent, all the provisions
          of this Lease shall be in full force and effect as soon as Tenant
          occupies the premises. In the event of such prior occupancy, Base
          Rent, Rent Adjustments and other charges shall be appropriately
          prorated.

                                       16
<PAGE>

                (j) Subject to Section 15 and in furtherance thereof, should any
          mortgage, leasehold or otherwise, require a modification or
          modifications of this Lease which modification or modifications will
          not bring about any increased cost or expense to Tenant or in any
          other way materially change the rights and obligations of Tenant
          hereunder, then and in such event, Tenant agrees that this Lease or
          the Non-Disturbance and Attornment Agreement (Exhibit "C") may be so
          modified.

                (k) Landlord and Tenant represent that neither has dealt with
          any broker other than Metropolitan Structures, Inc. and the Levy
          Organization as brokers in connection with this Lease, and that
          insofar as either knows no other broker negotiated this Lease or is
          entitled to any commission in connection therewith. Landlord and
          Tenant agree to indemnify and hold each other and Landlord's
          beneficiaries, Owner and Owner's partners and their respective agents
          and employees harmless from all claims of any other broker or brokers
          in connection with this Lease.

                (l) Landlord and Tenant agree that from time to time upon not
          less than thirty (30) days prior request by Landlord or Tenant,
          Landlord or Tenant will deliver to the other a statement in writing
          certifying (i) that this Lease is unmodified in full force and effect
          (or if there have been modifications that the same is in full force
          and effect as modified and identifying the modifications), (ii) the
          dates to which the Base Rent, Rent Adjustment, Rent Adjustment
          Deposits and other charges have been paid, (iii) that so far as the
          person making the certificate knows, the other is not in default under
          any provision of this lease, if such be the case, (iv)

                (m) Landlord's or Owner's title is and always shall be paramount
          to the title of Tenant, and nothing herein contained shall empower
          Tenant to do any act which can, shall or may encumber such title
          unless otherwise specified in this Lease.

                (n) The laws of the State of Illinois shall govern the validity,
          performance, construction and enforcement of this Lease.

                (o) 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
          enforceable, shall not be affected thereby and each term, covenant or
          condition of this Lease shall be valid and be enforced to the fullest
          extent permitted by law.

                (p) The term "Owner", as used in this Lease, means the
          beneficiary or beneficiaries of Landlord and if any such beneficiary
          shall be a partnership then any liability or obligation of said
          partnership under this Lease shall be limited to its partnership
          assets and no partner of said partnership shall be individually or
          personally liable for any claim arising out of this Lease. A deficit
          capital account of any such partner shall not be deemed an asset or
          property of said partnership.

                (q) If Tenant is a corporation, the persons executing this Lease
          on behalf of such corporation hereby represent and warrant that they
          have been duly authorized to execute this Lease for and on behalf of
          such corporation pursuant to a duly adopted resolution of its board of
          directors or by virtue of its bylaws.

                (r) Landlord and Tenant agree that should Landlord, in the
          exercise of its sole discretion, determine that a fire emergency exit
          (crash door) is required in the interest of public safety, Landlord
          may, at its sole expense, install such fire emergency exit (crash
          door) in any demising wall of the demised premises.

                (s) If Landlord is a bank as trustee under a trust, this Lease
          is executed by the undersigned trustee, not personally but solely as
          trustee and it is expressly understood and agreed by the parties
          hereto, anything contained herein to the contrary notwithstanding that
          each and all of the covenants, undertakings, representations and
          agreements herein made are made and intended, not as personal
          covenants, undertakings, representations and agreements of the
          trustee, individually, or for the purpose of binding it personally,
          but this Lease is executed and delivered by the trustee, solely in the
          exercise of the powers conferred upon it as such trustee under said
          trust agreement and no personal liability or personal responsibility
          is assumed by, nor shall at any time be asserted or enforced against
          said bank, the beneficiary of said trust or its Agent on account
          hereof, or on account of any covenant, undertaking, representation,
          warranty or agreement herein contained, either expressed or implied,
          all such personal liability, if any, being hereby expressly waived and
          released by the parties hereto or holder hereof, and by all persons
          claiming by or through or under said parties or holder hereof. Such
          trustee, hereby confirms that its beneficiary has the authority to
          manage the Building and has designated JMB/MS Management Co. as Agent
          for the Beneficiary in connection with the management of the Building.

                                       17
<PAGE>

                (t) Landlord neither represents nor warrants that the demised
          premises may be occupied or used for the purposes stated in this
          Lease.

                (u) Landlord and Tenant agree, that to the extent permitted by
          law, each shall and hereby does waive trial by jury in any action,
          proceeding or counterclaim brought by either against the other on any
          matter whatsoever arising out of or in any way connected with this
          Lease, the relationship of Landlord and Tenant. Tenant's use or
          occupancy of the premises and/or any emergency or statutory remedy.

25.      MEMBER SPACE.

A.       1. Landlord agrees to reserve ("Reservation") approximately 400,000
         square feet including the demised premises ("First Reservation Space')
         on the lowest office floors of the Building for lease to Tenant and to
         firms or individuals who are members in good standing ("Members") of
         Tenant. The Reservation shall terminate at midnight, April 30, 1982,
         unless 300,000 square-feet (including the demised premises) is leased
         by Tenant and/or Members on or before April 30, 1982, under which
         circumstances the Reservation shall be deemed automatically extended
         until midnight, October 31, 1982.

         2. If Tenant and Members lease all of the First Reservation Space,
         Landlord shall reserve and the Members may lease, during the
         Reservation, an additional 200,000 square feet ("Second Reservation
         Space") which is located immediately above the First Reservation Space.

         3. All Members leasing during the period commencing May 1, 1982 and
         ending October 31, 1982, and all Members leasing Second Reservation
         Space shall be deemed to have exercised the Work Option under Section
         29.

B.       1. Tenant shall advise Landlord of its designated corporate officer(s)
         who is authorized to act on its behalf ("Officer(s)") and Officer has
         the right (subject to Sections 25.B.2.(a) and (b), 26 and 30) to
         approve all leases between Landlord and Members who lease space under
         this Lease. Landlord may reject a lease with a Member if, in Landlord's
         reasonable judgment, the proposed Member is financially unqualified.
         Tenant's approval shall:

                a. take the form of the following inscription on the cover page
                of each Member lease (Exhibit "F" "Member Lease Form"):

                            The Chicago Mercantile Exchange hereby approves This
                            lease for Landlord's execution.

                                 CHICAGO MERCANTILE EXCHANGE

                                 By ____________________________ "Officer"
                                       Its

                                 Date __________________________

                b. subject to Sections 25.B.2.a. and b., not create any
                liability for Tenant under the lease approved by virtue of the
                approval.

                                       18
<PAGE>

         2. As to all First and Second Reservation Space leased by Members and
         all Member Five, Ten and Fifteen Year Space, Replacement Premises, and
         Offering Space, for which Tenant has given Landlord notice under
         section 25.D.1.c. or an Interest Notice under section 30, Tenant
         (Officer) is responsible for:

                a. making arrangements with Members for the leasing of space by
                Members in the areas of the Building and Phase II Tower (if
                designated by Landlord) described in this Lease ("Member Space")
                throughout the term of this Lease and during occupancy
                subsequent thereto pursuant to Section 30. In connection with
                the assignment to Members of Member Five, Ten and Fifteen Year
                Space or Replacement Premises, in either the Building or the
                Phase II Tower (if designated by Landlord) as the case may be,
                such space and any space previously located in the Member Space
                or the demised premises shall be assigned to Members or occupied
                by Tenant so that resulting occupancy by Tenant and Members of
                the demised premises and Member Space (other than Offering
                Space) will be contiguous. Tenant will be liable to Landlord for
                any loss or damage (including loss of Base Rent and/or Rent
                Adjustments) arising out of Tenant's failure to assign or occupy
                space in the foregoing manner, but no liability on the part of
                Tenant shall arise hereunder as a result of a Member default
                unless such Member was a Sublessor of Tenant or by reason of the
                expiration of a lease with a Member at a time when no lease with
                a Member for Member 5, 10, or 15 Year Space, or lease or
                amendment with Tenant for 5, 10 or 15 Year Space, or a lease for
                Replacement Premises or a lease for Offering Space will be
                commencing concurrently therewith.

                b. leasing Members' Space throughout the term of this Lease,
                with continuous rentals so that no rental timing gaps occur
                between the ending of one lease and the commencement of another.
                Therefore, rentals for Member Five, Ten and Fifteen Year Space
                (described in Section 25.D.) and Replacement Premises shall
                commence immediately upon their becoming available (in
                accordance with Section 25.D.R.) and be the obligation of the
                Member selected to take such space. If the Member does not
                satisfy this obligation the loss or damage (including loss of
                Base Rent and/or Rent Adjustments) for the timing gap is the
                obligation of Tenant but no liability on the part of Tenant
                shall arise hereunder as a result of a Member default unless
                such Member was a Sublessor of Tenant or by reason of the
                expiration of a lease with a Member at a time when no lease with
                a Member for Member 5, 10, or 15 Year Space, or lease or
                amendment with Tenant for 5, 10 or 15 Year Space, or a lease for
                Replacement Premises or a lease for Offering Space will be
                commencing concurrently therewith, and

                c. the relative priorities and the resolution of any conflicts
                of Sections 25, 26 and 30, and

                d. which Members are able to lease which space, and

                e. whether a Member may expand to contiguous or noncontiguous
                space, and

                f. whether a Member must or can relocate to Replacement Premises
                and the location of the Replacement Premises, and

                g. which Members may lease Member Five, Ten or Fifteen Year
                Space or Replacement Premises and the amounts thereof.

                h. which Members are able to lease First or Second Reservation
                Space.

         3. The assignment and designation of space for Member expansion, and/or
         Replacement Premises shall accompany the notices given under Section
         25.D.1.c.

         4. If Officer does not make any decision or selection when required
         under this Lease, Landlord may make such decision or selection on
         behalf of Officer.

         5. The form of leases with Members until the Reservation expires shall
         take the Members' Lease Form. Thereafter all leases with Members shall
         be on Landlord's then current form excepting only:

                a. leases with Members for Member Five, Ten and Fifteen Year
                Space and Replacement Space; and

                b. leasing pursuant to Section 30.

                                       19
<PAGE>

C.       The annual Base Rent rate per square foot, Rent Adjustments and the
         lease terms to Members for the First and Second Reservation Spare are
         as follows:

         1. First Reservation Space:

                a. annual Base Rent rate per square foot is $19.75 or, $20.25 if
                the Member has or is deemed to have exercised the Work Option
                under Section 29.

                b. The Rent Adjustments are as stated in this Lease.

         2. Second Reservation Space:

                a. annual Base Rent rate per square foot is $25.00 and the
                Member is deemed to have exercised the Work Option under Section
                29.

                b. The Tax and Expense Rent Adjustments are as stated in this
                Lease.

                c. The CPI portion of the Rent Adjustment is forty percent (40%)
                instead of thirty percent (30%) so that Section 2(a) is changed
                as follows:

                    (xxi) line 2 - 30% changes to 40%;
                    (xxi) line 7 - 30% changes to 40%;
                    (xxii)1(a) line 5 - 30% changes to 40%;
                    (xxii)1(a) line 9 - 30% changes to 40%
                    (xxii)2(a) line 6 - 30% changes to 40%;
                    (xxii)2(a) line 12 - 30% changes to 40%.

                d. the CPI portion of the Rent Adjustment commences on the first
                (1st) day of the thirteenth (13th) month of the Lease term so
                that Section 2(b) is changes as follows:

                    Line 2 - 37th is changed to 13th;
                    Line 5 - 37th is changed to 13th;
                    Line 7 - 37th is changed to 13th.

                f. The example on page 43 is deemed modified accordingly.

         3. The length of the lease term to Members shall be either five (5) or
         ten (10) years (at the option of Tenant) depending on whether the
         Members are located in Tenant's Five, Ten or Fifteen Year Space
         (defined in Section 26). Subsequent to the termination of the
         Reservation, excepting only the leasing of Member Five, Ten or Fifteen
         Year Space or Replacement Premises, all leasing to Members under this
         Lease shall be pursuant to Section 30.

D.       Members Expansion.

         1. Members may lease expansion space under the following terms and
         conditions:

                a. the Member is not then in default by virtue of an existing
                money or other material default;

                b. the Member has leased space from the First Reservation Space;

                                       20
<PAGE>

                c. Landlord receives notice from Tenant (Officer) on or before
                the:

                      (i) fourth (4th) Anniversary for Member Five Year Space
                      (defined below);

                      (ii) ninth (9th) Anniversary for Member Ten Year Space
                      (defined below);

                      (iii) fourteenth (14th) Anniversary for Member Fifteen
                      Year Space (defined below);

                d. such notices are accompanied by the assignment and
                designation required under Section 25.B.

         2.     a.    Landlord shall deliver space as follows:

                      (i) as a result of the fourth Anniversary notice, up to
                      twenty percent (20%) of the Members' total demised
                      premises leased from First Reservation Space during the
                      Reservation ("Member Five Year Space"). Leases written by
                      Landlord in such space to Members or others are "Third
                      Party Five Year Leases".

                      (ii) as a result of the ninth Anniversary notice, up to
                      twenty percent (20%) of the Members' total demised
                      premises leased from First Reservation Space during the
                      reservation ("Member Ten Year Space"). Leases written by
                      Landlord in such space to Members or others are "Thirty
                      Party Ten Year Leases".

                      (iii) as a result of the fourteenth Anniversary notice, up
                      to twenty percent (20%) of the Members' total demised
                      premises leased from First Reservation Space during the
                      reservation ("Member Fifteen Year Space"). Leases written
                      by Landlord in such space to Members or others are "Thirty
                      Party Fifteen Year Leases".

                      (iv) in addition to the Member Five, Ten and Fifteen Year
                      Space, Landlord shall deliver space required to relocate
                      Members who leased First Reservation Space and are
                      displaced as a result of Tenant exercising its expansion
                      options pursuant to Section 26 ("Replacement Premises").
                      Leases written by Landlord in such space are called
                      "Replacement Leases".

                b. if the square footage delivery requirements stated require
                Landlord to split an existing suite, any remainder must, in
                Landlord's sole reasonable judgment, be marketable.

         3.     a.    the Member Five, Ten and Fifteen Year Space and
                Replacement Premises may be located either;

                                       21
<PAGE>

                      (i) in the Members' Space, or

                      (ii) in the succeeding floors of the Building immediately
                      above the Members' Space or, at the discretion of Landlord
                      in the lower part of the Phase II Tower.

                b. Landlord shall use reasonable efforts to lease the Member
                Five, Ten and Fifteen Year Space and the Replacement Premises
                for five and ten year terms and a reasonable mix thereof.

                c. Third Party Five, Ten and Fifteen Year Lease terms (in any
                combination of renewals or reletting) may not exceed five (5),
                ten (10 or fifteen (15) years respectively.

         4.     a. The Members' terms for Member Five, Ten and Fifteen Year
                Space and Replacement Premises shall be five (5) years and Base
                Rent and Rent Adjustments shall commence on the later of:

                      (i) the vacation by the previous tenant;

                      (ii) the termination of Third Party Five, Ten and Fifteen
                      Year Lease or a Replacement Lease;

                      (iii) the completion of the Building Standard work if the
                      space has never been leased and the Member to occupy has
                      either exercised or has been deemed to have exercised the
                      Work Option pursuant to Section 29.

                b. If a Member's lease during the Reservation was for a ten (10)
                year term and if such Member exercises an option for Member Five
                Year Space, the term for such Member's Member Five Year Space
                only, may at Member's option be for a term of five (5) years and
                extend beyond the term of the Member's lease for its demised
                premises.

         5.     The Members annual Base Rent rate per square foot for Member
         Five, Ten and Fifteen Year Space and Replacement Premises is as
         follows:

                a. Subject to Section 25.D.5.c., if the Member's lease during
                the Reservation is for a five (5) year term, the annual Base
                Rent rate per square foot for such member Five, Ten and Fifteen
                Year Space and Replacement Premises required, if any, shall
                equal Prevailing Market.

                b. If the Member's lease during the Reservation was for a ten
                (10) year term;

                      (i) the annual Base Rent rate per square foot for such
                      Member's Member Five Year Space shall equal the Base Rent
                      Rate Per Square Foot plus the Rent Adjustment Rate Per
                      Square Foot the Member is paying for its demised premises
                      at the time the term for the Member Five Year Space
                      commences.

                                       22
<PAGE>

                       (ii) Subject to Section 25.D.5.c., the annual Base rent
                      rate per square foot for such Member's Member Ten and
                      Fifteen Year Space and Replacement Premises required, if
                      any, shall equal Prevailing Market.

                c. Excepting only Section 25.D.5.b.(1), under any and all
                circumstances, the Members' annual Base Rent rate per square
                foot for Member Five, Ten or Fifteen Year Space or Replacement
                Premises shall, subsequent to the tenth (10th) Anniversary of
                this Lease, equal Prevailing Market.

         6.     Subject to Section 25.D.5.c., if any Third Party Five, Ten or
         Fifteen Year Lease terminates prior to its stated termination date
         ("Third Party Prior Date"), and if the Third Party Prior Date;

                a. is the result of a tenant default, and

                b. if the Third Party Prior Date occurs subsequent to two (2)
                years after the Commencement Date for Member Five Year Space,
                seven (7) years for Member Ten Year Space or twelve (12) years
                for Member Fifteen Year Space

         the Third Party Prior Date shall be deemed the termination date of such
         lease for purposes of Members expansion. Landlord shall provide Officer
         notice ("Third Party Expiration Notice") of the lease such space on
         behalf of a Member on or before fifteen (15) days after such Notice. If
         a Member does so exercise, it shall be deemed an exercise for Member
         Five Year Space if the exercise occurs prior to the 5th Anniversary. If
         the exercise occurs after the 5th Anniversary but before the tenth
         (10th) Anniversary, the exercise shall be deemed for Member Ten Year
         Space. If the exercise is subsequent to the tenth (10th) Anniversary,
         the exercise shall be deemed for Member Fifteen Year Space. If however,
         a Member does not exercise such option, Landlord may lease such space
         to a tenant for a term not to exceed five (5) years and the expiration
         date of such lease shall be deemed to be the expiration of a Third
         Party Five, Ten or Fifteen Year Lease depending on whether such
         expiration occurs subsequent to the 5th, 10th or 15th Anniversary.
         Subsequent options are then 5 and/or 10 years thereafter instead of at
         the times stated in Section 25.D.1.

         7. The Member Five, Ten and Fifteen Year Space or Replacement Premises
         shall be accepted by members in its "as-built" condition and
         configuration as of the date the term for such space commences, unless
         such space has never been occupied, under which circumstances Landlord,
         if a Member has or is deemed to have exercised the Work Option for its
         initial demised premises, shall construct it to Building Standard as
         described on Attachment "A" to the Work Letter attached to

                                       23
<PAGE>

         this Lease. If a Member has not or has not been deemed to have
         exercised the Work Option and if such Space has never been occupied, a
         credit as set forth in Section 28 shall be granted for the amount of
         Member Five, Ten or Fifteen Year Space or Replacement Premises taken.

         8. If a tenant of the Member Five, Ten of Fifteen Year Space or
         Replacement Premises holds over, Landlord shall use reasonable efforts
         to evict such holdover tenant.

         9. Landlord will endeavor to lease the Member Five, Ten and Fifteen
         Year Space and the Replacement Premises to entire floor tenants but it
         is understood that marketing conditions will probably preclude such.

E. It is understood that a Member may lease space in the Building or the Phase
II Tower outside the terms of this Lease. Under such circumstances Landlord and
such member may deal directly with each other and Tenant shall be neither
involved nor responsible.

         26.    EXPANSION OPTIONS.

Tenant, provided it is not then in default by virtue of an existing money or
other material default under this Lease, may lease additional space under the
following terms and conditions:

A. If Landlord receives notice from tenant on or before the fourth (4th)
Anniversary, Tenant (subject to Section 26.F) may require Landlord to deliver
space up to twenty percent (20%) of the Tenant's demised premises leased prior
to the expiration of the Reservation ("Five Year Space"). Leases written by
Landlord in such space to Members or others are called "Five Year Leases".

B. If Landlord receives notice from Tenant on or before the ninth (9th)
Anniversary, Tenant (subject to Section 26.F) may require Landlord to deliver
space up to twenty percent (20%) of the Tenant's demised premises leased prior
to the expiration of the Reservation ("Ten Year Space"). Leases written by
Landlord in such space to Members or others are called "Ten Year Leases".

C. If Landlord receives notice from tenant on or before the fourteenth (14th)
Anniversary, Tenant (subject to Section 26.F.) may require Landlord to deliver
space up to twenty percent (20%) of the Tenant's demised premises leased prior
to the expiration of the Reservation ("Fifteen Year Space"). Leases written by
Landlord in such space to Members or others are called "Fifteen Year Leases".

D. The term for Five, Ten and Fifteen Year space leased by Tenant shall commence
on the later of the vacation by the previous tenant or the termination of Five,
Ten and Fifteen Year Leases and thereupon shall be considered demised premises,
subject to all terms and conditions of this Lease. Five, Ten and Fifteen Year
Lease terms (in any combination of renewals or reletting) may not exceed five
(5), ten (10) or fifteen (15) years respectively.

                                       24
<PAGE>

E. The Five, Ten and Fifteen Year Space may be located either;

         1. on the portion of the highest floor of the demised premises not
         entirely within the demised premises and sequentially on whole floors
         immediately above the demised premises,

                                       or

         2. in the Phase II Tower

at the discretion of Landlord. If the Phase II Tower be selected, Landlord shall
make reasonable efforts to designate the lower floors (sequentially).

F. If the square footage delivery requirements stated require Landlord to split
an existing suite, any remainder must, in Landlord's sole reasonable judgment,
be marketable.

G. The annual Base Rent rate per square foot for the Five, Ten and/or Fifteen
Year Space leased to Tenant shall equal:

         1. the Base Rent Rate Per Square Foot of the demised premises at the
         time the term for the Five, Ten and/or Fifteen Year Space commences;
         plus

         2. the Rent Adjustment Rate Per Square Foot of the demised premises at
         the time the term for the Five, Ten and/or Fifteen Year space
         commences.

H. If Tenant properly exercises any option contained in this Section 26, this
Lease shall be revised by Landlord to reflect changes in the size of the demised
premises, Base Rent, monthly installments of Base Rent and Tenant's Proportion,
all of which shall be increased for each square foot by which the demised
premises are increased. A copy of such revisions shall be sent to Tenant within
a reasonable time after Tenant's exercise.

I. If any Five, Ten or Fifteen Year Lease terminates prior to its stated
termination date ("Prior Date"), and if the Prior Date;

         1. is the result of a tenant default, and

         2. if the Prior Date occurs subsequent to two (2) years after the
         Commencement Date for Five Year Space, seven (7) years for Ten Year
         Space or twelve (12) years for Fifteen Year Space,

                                       25
<PAGE>

the Prior Date shall be deemed the termination date of such lease for purposes
of this Section 26. Landlord shall provide Tenant notice ("Expiration Notice")
of the Prior Date and Tenant may exercise an option to lease such space on or
before fifteen (15) days after such Notice. If Tenant does so exercise, it shall
be deemed an exercise for Five Year space if the exercise occurs prior to the
Fifth Anniversary. If the exercise occurs after the Fifth Anniversary, but
before the Tenth Anniversary, the exercise shall be deemed for Ten Year Space.
If the exercise is subsequent to the Tenth Anniversary the exercise shall be
deemed for Fifteen Year Space. If under such circumstances, Tenant does not
exercise its option, Landlord may lease such space to a tenant for a term not to
exceed five (5) years and the expiration date of such lease shall be deemed to
be the expiration of a Five, Ten or Fifteen Year Lease depending on whether such
expiration occurs subsequent to the Fifth, Tenth or Fifteenth Anniversary.
Subsequent options are then 5 and/or 10 years thereafter instead of at the times
stated in Section 26.B and 26.C.

J. The Five, Ten and Fifteen Year Space shall be accepted by Tenant in its
"as-built" condition and configuration as of the date the term for such space
commences, unless such space has never been occupied, under which circumstances
Landlord, if Tenant has exercised the Work Option contained in Section 29 for
the initial demised premises, shall construct it to Building Standard as
described on Attachment "A" to the Work Letter attached to this Lease. If Tenant
has not exercised the Work Option, and if such space has never been occupied, a
credit as set forth in Section 28 shall be granted for the amount of expansion
space taken.

K. If a tenant of the Five, Ten or Fifteen Year Space holds over, Landlord shall
use reasonable efforts to evict such holdover tenant.

         27.    RENEWAL OPTION.

A. Tenant may extend the Termination Date of this Lease ("Renewal Option") for a
period of ten (10) years ("Extension") upon the terms and conditions stated
below if:

         1. Landlord receives notice on or before the 19th Anniversary; and

         2. Tenant is not then in default by virtue of an existing money or
         other material default under this Lease.

B. The annual Base Rent per square foot for the demised premises during the
Extension shall equal Prevailing Market.

                                       26
<PAGE>

C. If Tenant properly exercises this Renewal Option, this Lease shall be revised
by Landlord to reflect changes in Base Rent, monthly installments of Base Rent,
Termination Date and other appropriate terms. A copy of such revisions shall be
sent to Tenant within a reasonable time after such exercise.

D. Occupancy of the demised premises by Tenant subsequent to the Extension shall
be pursuant to Section 30 of this Lease and may continue indefinitely so long as
Tenant exercises its rights under Section 30 and leases continuously. Subsequent
to the expiration of the Lease term or Extension if Tenant leases the demised
premises pursuant to Section 30, such leasing shall be deemed (for purposes of
Section 30 only) to have occurred during the Extension.

         28.    TENANT'S AND MEMBER'S CREDIT.

         If Tenant or a Member does not or is not deemed to have exercised the
Work Option (defined in Section 29):

         A.     Landlord hereby grants Tenant and Members the following amounts
         to be applied toward the cost of material and labor supplied in their
         premises;

                1. To Tenant:  $10.00 multiplied by the Rentable Area of the
                demised premises.

                2. to Members: $10.00 multiplied by the Rentable Area of their
                demised premises.

         B.     Section 29 shall be deemed null and void.

         C.     Tenant and Member shall nevertheless contract with Metropolitan
         Structures, Inc. in accordance with the Work Letter for all material
         and labor to be supplied in their demised premises except that Tenant
         need not employ Metropolitan Structures for 1) material or labor or
         specialized or technical matters, e.g. computer installation or the
         communication system in its support area and 2) the area within
         Tenant's support area (not to exceed 50,000 square feet) covered by the
         contract entitled "Chicago Mercantile Exchange Trading Floor Project
         Interior Architects Agreement" by and between Tenant and Space
         Management Program, Inc. The amount of credit granted for the area
         under this credit shall be $10.00 per square foot if the Base Rent is
         $19.75 per square foot or $13.00 per square foot if the Base Rent is
         $20.25 per square foot. Section 8 of the Lease shall nevertheless be
         complied with. The Work Letter shall be deemed applicable except as
         follows:

                1. Attachment "A" shall be deemed deleted;

                2. All Plans (defined in the Work Letter), material and labor
                supplied shall be at Tenant's and/or Members sole cost and
                expense but shall be deemed Work and/or Tenant Extra Work as
                such are defined in the Work Letter;

                                       27
<PAGE>

                3. Section IIA(5) and IIB shall be deemed deleted and replaced
                with:

                "IIA(5)     Tenant agrees to pay Agent in the manner hereinafter
                            set forth in this paragraph the following sums for
                            the Work and/or Tenant Extra Work:

                            (a)     up to and including $13.00 (which includes
                                    7.5% thereof as General Conditions) per
                                    square foot of Rentable Area of the demised
                                    premises, all subcontract costs, plus 4%
                                    (builders fee), and

                            (b)     on that portion in excess of $13.00 per
                                    square foot of Rentable Area of the demised
                                    premises, all subcontract costs (which shall
                                    include a 5% non-refundable contingency to
                                    assure a fixed price and 7.5% of the total
                                    thereof for General Conditions) plus 21% of
                                    the total thereof for overhead and profit.
                                    If Tenant or Member does not desire a fixed
                                    price, the 5% non-refundable contingency
                                    shall be eliminated.

                IIB         Tenant shall pay Agent all such charges (net of
                            credits) promptly upon being billed therefor at any
                            time and from time to time. Such sums shall be
                            deemed additional Base Rent for purposes of Section
                            18 only of the Lease.

         29.    BUILDING STANDARD WORK OPTION.

A. Tenant and Members, by notice to Landlord on or before April 30, 1982, may
elect to have Landlord construct, at Landlord's sole cost and expense, the
Building Standard Work (shown on Attachment "A" to the Work Letter attached to
this Lease) in their demised premises ("Work Option").

B. If Tenant and/or the Members exercise or are deemed to have exercised the
Work Option:

         1. the Work Letter and Attachment "A" to the Work Letter shall become
         operative, and

         2. the annual Base Rent rate per square foot for the demised premises
         and/or the Members premises for Members who have leased First
         Reservation Space, shall be increased from $19.75 to $20.25, and

         3. Section 28 shall be deemed null and void, and

         4. this Lease and the Members Leases shall be revised by Landlord to
         reflect changes in Base Rent, monthly installments of Base Rent and the
         credits granted in Section 31 (stated in Column B) if any A copy of
         such revisions shall be sent to Tenant and Member promptly after
         Tenant's and/or Members' exercise.

                                       28
<PAGE>

         30.    RIGHT OF FIRST OFFERING.

A. During the term of this Lease (or Extension or subsequently in accordance
with Section 27.D.) so long as Tenant is a tenant in the Building, Tenant or
Members (at the sole election and designation of and by Tenant (Officer)) shall
have the right to lease the Offering Space (defined below) under the terms
stated in Exhibit "B" ("Advice"). If Tenant desires or desires to indicate a
Member's desire to lease Offering Space, Tenant shall give Landlord notice
("Interest Notice") naming the Member, if applicable, and within forty-five (45)
days after receipt of such, Landlord shall give Tenant an Advice stating the
terms it proposes to offer the Offering Space, or any part thereof, to other
tenants. Landlord's obligation to give the Advice is contingent upon:

         1. Tenant (or the Member) not being then in default by virtue of an
         existing money or other material default under this Lease (or the
         Member's lease if a member);

         2. Landlord's receipt of the Interest Notice for any portion of the
         Offering Space (except B.7. below) during the period commencing two (2)
         years prior to the expiration date of each Offering Lease (defined
         below) and ending 460 days thereafter. For the space on the ten (10)
         lowest office floors of the Phase II Tower, Tenant need not give an
         Interest Notice, but Landlord shall give an Advice when it commences
         marketing such space; and

         3. the Offering Lease not being extended or renewed pursuant to an
         option contained as an original clause in the Offering Lease; and

         4. the Offering Space not being subject to an exercised expansion or
         renewal option contained in a lease to another tenant.

         5. the Offering Space (excepting 30.B.7.) having been leased to another
         tenant at least once.

B. The Offering Space is the space located:

         1. in the demised premises, and

         2. in Tenant's Five, Ten or Fifteen Year Space, and

         3. in Members Space leased from First Reservation Space, and

         4. in Member Five, Ten or Fifteen Year Space and Replacement Premises,
         and

         5. on the five full floors immediately above Member Five, Ten or
         Fifteen Year Space or Replacement Premises, and

         6. sufficient space on the floors immediately above such five full
         floors equal to the difference between 400,000 square feet and the
         total space leased by Tenant and Members (from First Reservation Space
         only) during the Reservation, and

         7. on the ten (10) lowest office floors of the Phase II Tower.

                                       29
<PAGE>

C. This right of first offering ("ROFO") shall be exercised by Tenant (only) as
follows:

         1. if the Offering Space is vacant or becomes vacant, or if the
         Offering Lease has ninety-two (92) days or less remaining in its term,
         or if a Second Advice (defined below) is given for an Offering Space,
         Tenant (and Member) must execute and deliver the Advice (or Second
         Advice) to Landlord within fifteen (15) days after its date;

                                      -or-

         2. if the Offering Space is occupied under a non-defaulted lease with
         more than ninety-two (92) days remaining in its term, Tenant (and
         Member) must execute and deliver the Advice to Landlord within
         forty-five (45) days after its date,

                                      -and-

         3. within twenty (20) days after the fifteen (15) days (Section 30 C 1)
         or the forty-five (45) days (Section 30 C 2), Tenant's or Member's (as
         the case may be) execution of a lease in the form of this Lease if
         Tenant or in the Member Lease Form if a Member (or appropriate
         amendments in either case), except that to the extent there are any
         economic differences between the Advice and this Lease or the Members
         Lease Form, the Advice shall prevail and control and either this Lease
         or the Members Lease Form shall be amended to conform to the Advice.

D. If the ROFO is exercised the term for the Offering Space shall commence upon
the later of the vacation of the Offering Space by the existing tenant or the
expiration of the existing lease for such space ("Offering Lease") and end in
accordance with the term stated in the Advice.

E. If Tenant fails to exercise the ROFO, Landlord shall be free to lease such
space upon terms which are the same as or different from those set forth in the
Advice or this Section 30, except that if Landlord changes any of items 1
through 10 of the Advice, Tenant" Right of First Offering for such space shall
again become operative on the date of a new Advice ("Second Advice"". If however
the total economic effect of any change results in no overall economic impact or
an impact which is more favorable to Landlord (e.g. greater rent), a Second
Advice is not required, e.g. if the base rent is increased by $14,275.00 over a
five (5) year term and if the credits are increased by $10,000.00 there would be
no economic impact for purposes of this Section 30 (this example uses a fifteen
percent (15%) per annum constant).

F. This Section 30 shall not be excluded from applicability to space as a result
of Tenant's prior failure to exercise its rights hereunder or under Section 26
on a particular space or as a result of Tenant or a Member leasing such space
pursuant to this Section 30.

                                       30
<PAGE>

G. If a lease in Offering Space terminates prior to its stated termination date,
Landlord shall give Tenant notice and Tenant thereupon has fifteen (15) days to
give an Interest Notice.

H. Tenant's giving an Interest Notice or Landlord's giving of an Advice shall
not be deemed to confer on Tenant or Members any rights or obligations other
than those set out in this Section 30.

I. If Landlord is not required to give an Advice, it shall give a Non-Advice
which states the reason(s) an Advice is not necessary. The Non-Advice shall be
given within the same time requirements as an Advice.

         31.    RENT CREDIT.

A. As a concession to Tenant and Members, if, as to each, the Plans Due Date
(Work Letter) is met and if, as to each Member and Tenant, their demised
premises is within the First Reservation Space, Landlord hereby grants to Tenant
and such Members a credit in the sums stated below (Column A or if Tenant or a
Member exercises or is deemed to have exercised the Work Option contained in
Section 29, Column B) to be applied against the monthly installments of Base
Rent due as follows:

For Tenant:
                                     Column A          Column B
Month                                 Amount            Amount
-----                                 ------            ------
For 2nd month of Lease term         $164,583.34       $168,750.00
For 3rd month of Lease term          164,583.34        168,750.00
For 4th month of Lease term          164,583.34        168,750.00
                                   ------------      ------------

                      Total        $493,750.02        $506,250.00

For Members:

                                  Column A          Column B
Month                              Amount            Amount
-----                              ------            ------
For 2nd month of lease term   $19.75 x Rentable  $20.25 x Rentable
                              Area of premises   Area of premises
                              -----------------  -----------------
                                     12                 12

For 3rd month of lease term   $19.75 x Rentable  $20.25 x Rentable
                              Area of premises   Area of premises
                              -----------------  -----------------
                                     12                 12

For 4th month of lease term   $19.75 x Rentable  $20.25 x Rentable
                              Area of premises   Area of premises
                              -----------------  -----------------
                                     12                 12

A default as to the Plans Due Date by Tenant or any Member shall not affect the
right of any non-defaulting party (Tenant or Member) to receive the foregoing
credit.

B. Rent Adjustments, if any, due for any, due for any months to which a credit
is applied shall be paid as provided in Sections 1 and 2 of this Lease or the
Members' Lease form.

                                      31
<PAGE>

         32.    MINIMUM SPACE.

                It is agreed that Tenant and Members will, on or before April
         30, 1982, execute leases for no less than 250,000 square feet in the
         Building. To the extent that such amount of space is not so leased, at
         Landlord's option, either;

A. the demised premises under this Lease shall, by appropriate amendments to be
executed by Tenant on or before May 30, 1982, be increased (at locations
contiguous to the demised premises designated by Landlord) by the difference
between 250,000 square feet and the amount leased by Tenant and Members, or

B. Landlord may lease such space to others subject to this Lease.

         33.    RESERVED PARKING.

A. Upon completion of a Building automobile parking facility ("Facility"),
Landlord shall cause the operator of the Facility ("Operator") to make the
"derived number" (defined below) of monthly parking privileges ("Privileges")
available to Tenant and Members through Officer. Tenant or Members (as the case
may be) shall:

         1. seek from Officer the availability of Privileges;

         2. pay the monthly charges for the Privileges at the rate charged by
         the Operator from time to time;

         3. contract with Operator for the Privileges within sixty (60) days
         after the later of (a) its occupancy of demised premises, or (b)
         completion of the Facility (Landlord shall use reasonable efforts to
         give Tenant notice on or before thirty (30) days prior to the date the
         Facility is to be completed);

         4. use the Privileges so contracted on a continuous basis.

If Tenant or Members fail to pay, contract or continuously use any of such
Privileges, Landlord need no longer cause such Privileges to be made available.

B. Tenant's and Member's (who have leased First Reservation Space) derived
number of parking privileges shall be determined from the following formula:

                                       32
<PAGE>

       Rentable Area of demised premises plus space
       Leased by Members from First Reservation Space
       And expansion space leased from time to time    X  500  X  120%  =  N
       ---------------------------------------------
             Rentable Area of Building and the
             Phase II tower (if and when built)

N = number of parking privileges for Tenant and Members. (Note:  The number of
privileges so derived may not exceed eighty percent (80%) of the number of
privileges contained in the Facility.)

C. Landlord warrants that the Facility when completed in the Building and the
Phase II Tower will contain approximately 500 privileges for the Building and
the Phase II Tower. Upon completion of the Phase II Tower, N shall be reduced by
recalculation using the above formula.

D. The number of Tenant and Members (who have leased First Reservation Space)
privileges shall be adjusted for fluctuations in occupancy on each successive
Five Year Anniversary of this Lease. Under no circumstances, however, may the
total number of privileges Tenant and Members have exceed eighty percent (80%)
of the Facility.

E. Members who lease Second Reservation space shall obtain Privileges on a
prorata basis (100% not 120%).

         34.    DELIVERY OF PREMISES.

A. After the execution of this Lease, Landlord agrees to use reasonable efforts
to:

         1. make the Building, the demised premises and the Members' demised
         premises Ready for Occupancy on or before forty-four (44) months after
         Landlord's obtainment of a Foundation Permit for the Building
         (Completion Date);

         2. give Tenant no less than thirty (30) days advance notice of the
         Completion Date;

         3. obtain a Foundation Permit by September 30, 1981;

         4. advise Tenant of the date the Foundation Permit is obtained.

B. If Landlord is delayed by an Act of Tenant or an Act of a Member or if the
Completion Date is delayed by an Act of Tenant or an Act of a Member, the
demised premises* or the Member's demised premises for the delaying party
(Tenant or a Member) only shall be deemed Ready for Occupancy on the date they
would have been ready had such a delay not occurred and Landlord shall be
entitled to give notice of the Commencement Date in accordance with the demising
section (first unnumbered complete section) found on page 1 of this Lease.

* for the delaying party (Tenant or a Member) only

                                       33
<PAGE>

C. If, for any reason other than an Act of Tenant or an Act of a Member, the
Building, the demised premises and the Member's demised premises are not Ready
for Occupancy by January 1, 1987, or if Landlord has not obtained a Foundation
Permit by July 31, 1982, or if Landlord's Beneficiary gives a notice of the
Abandonment Date pursuant to Article VI, Section 6.1 of the Agreement for Sale
of Trading Floor Area and Construction of Trading Floor by and between C.M.E.
Center, an Illinois Limited Partnership and C.M.E. Real Estate Co.,* Tenant and
Members on notice to Landlord (on or before ninety (90) days after the event)
may terminate their Leases. In the event of such termination, neither Landlord,
Tenant nor Members shall have any liability to the other other than Landlord
shall refund monies paid to it by Tenant or Members.

         35.    FABER'S RESTAURANT.

         Landlord agrees that without Tenant's prior consent, Landlord may not
lease space in the Building for a Faber's Restaurant (owned by or named
Faber's).

         36.    RETAIL SPACE.

A. Landlord grants Tenant an option ("Retail Option") to lease up to an
additional 4,025 square feet located in the retail area of the Building ("Retail
Space"), if:

         1. Landlord receives notice of Tenant's exercise on or before June 30,
         1982; and

         2. the location of the Retail Space is in a location mutually agreed
         upon by Landlord and Tenant.

B. If Tenant exercises the Retail Option:

         1. the Retail Space shall be added to the demised premises and
         thereupon be subject to all the terms and conditions of this Lease;

         2. the Retail Space shall be used and occupied for the purpose stated
         on page 1 of this Lease;

         3. this Lease shall be revised to reflect changes in the size of the
         demised premises, Base Rent (increased at the rate (annual) of $30.50
         per square foot of Retail Space), monthly installments of Base Rent,
         Tenant's Proportion, all of which shall be increased for each square
         foot by which the demised premises are increased. The Work Option
         (Section 29) and the credits (Section 31, Column A or B) are not
         applicable to the Retail Space. A copy of such revisions shall be sent
         to Tenant promptly after Tenant's exercise; and

*  (The "Trading Floor Agreement") and such notice of the Abandonment Date has
not been rescinded within the time period set forth therein by the Lender
described in the Trading Floor Agreement, or if such Trading Floor Agreement is
terminated by C.M.E. Real Estate Co. pursuant to the provisions of Section 4.1
thereof, then

                                       34
<PAGE>

         4. Landlord shall construct the Retail Space to Building Standard as
         described on Attachment "B" to the Work Letter attached to this Lease.

         5. Notwithstanding anything hereinbefore contained in this Lease, there
         shall be no abatement or reduction of that portion of the Base Rent
         payable for Retail Space ("Retail Rent Portion") except to the extent
         the Retail Space shall be decreased pursuant to Section 9, rendered
         untenantable pursuant to Sections 3(C) or 10, or taken pursuant to
         Section 12, in which event any abatement or reduction of the Retail
         Rent Portion shall be in proportion to the amount of the decreased,
         untenantable or taken area of the Retail Space.

         37.    TENANT ENTRANCE.

         Tenant is granted the right at its sole expense to maintain a guard
service at an evening and weekend Building entrance/exit of its choosing.

         38.    PRIVATE RESTAURANT CLUB SPACE.

A. Landlord grants Tenant or a group of Members (approved by Officer and
Landlord ("Group")) an option ("Club Option") to lease approximately 12,500
square feet located on Upper Lobby Level (Exhibit A-1 ("Club Space")) for a
private restaurant ("Club"), if:

         1. Landlord receives notice of exercise on or before June 30, 1982; and

         2. such notice of exercise is accompanied by cash from Tenant or Group
         in the sum of $232,000.00 which shall be deposited in an interest
         bearing construction escrow account to be used for construction and
         furnishing the Club, with the interest enuring to the benefit of Tenant
         or Group, and

         3. on or before March 31, 1983 Tenant's or Group's deposit of an
         additional $463,000.00 in such escrow account, and

         4. the location, configuration, size and nature of construction of the
         Club Space and chattel improvements have been mutually agreed upon by
         Landlord and Tenant.

                                       35
<PAGE>

B. If Tenant or Group properly exercise this Club Option and the conditions in
Section 38(A) occur;

         1. A lease on the Members Lease Form for a twenty (20) year term (with
         no Work Letter and no Attachment "A") shall be prepared to reflect Base
         Rent (at the rate (annual) of $25.00 per square foot of Club Space
         under lease). The Work Option (Section 29) and the credits stated in
         Section 31 (Column A or B) are not applicable to the Club Space and the
         default provisions (Section 18) shall be modified so that if a default
         occurs, Landlord's only remedy will be to obtain possession of the Club
         Space. Landlord shall have no right to proceed against Tenant or Group
         for delinquent rentals.

         2. Tenant or Group shall: a) accept the Club Space "as-is", there being
         no construction required therein by Landlord, and b) construct and
         equip the Club in accordance with plans and specifications which have
         been approved by Landlord and Tenant.

         3. Notwithstanding anything hereinbefore contained in this Lease, there
         shall be no abatement or reduction of that portion of the Base Rent
         payable for Club Space ("Club Rent Portion") except to the extent the
         Club Space shall be decreased pursuant to Section 9, rendered
         untenantable pursuant to Sections 3(C) or 10, or taken pursuant to
         Section 12, in which event any abatement or reduction of the Club Rent
         Portion shall be in proportion to the amount of the decreased,
         untenantable or taken area of the Club Space.

         4. Landlord hereby grants Tenant or the Group a credit in an amount not
         to exceed $463,000.00 to be applied, at their direction, toward the
         cost of materials or labor supplied for the construction of the Club.

         5.     (a) In addition to the credit in subsection 4 hereof, Landlord
                agrees to advance ("Advance") the Tenant or Group up to
                $695,000.00 to be applied to the cost of materials or labor
                supplied for the construction of the Club, provided however,
                that the Advance may be in increments or $10,000.00 only. For
                example, if $19,500.00 is requested, $10,000.00 shall be
                advanced, if $71,200.00 is requested, $70,000.00 shall be
                advanced.

                (b) Tenant's request for the Advance shall take the form (sworn
                statements) outlined in Section 8 of this

                                       36
<PAGE>

                Lease.  Landlord shall make direct payment to contractors for
                all Advances requested and after the last Advance, the total
                Advance shall be set.

                (c) Subsequent to the setting of the total Advance, Landlord
                shall obtain repayment by increasing the total Base Rent and
                each monthly installment thereof by $131.67 for each $10,000.00
                Advanced. The increase in the total Base Rent shall be
                determined by multiplying the increase in the monthly
                installments of Base Rent (as determined above) by the number of
                months in the lease term. The lease for the club shall be
                revised by Landlord to reflect such changes. A copy of such
                revisions shall be sent to the Tenant or Group promptly after
                the Advance is set.

C. Under any and all circumstances all decorations, improvements, chattels,
equipment, personal property, fixtures and trade fixtures of any kind or
description put into the Club must be fully paid for as such items are
installed. In the event of default under the lease for the Club Space, and in
the event such default results in the exercise of Landlord's right to terminate
the lease for the Club Space and/or terminate the tenant's right to occupy the
Club Space, all decorations, improvements, chattels, equipment, personal
property, fixtures and trade fixtures of any kind or description shall
automatically become the property of Landlord with no bill of sale being
required.

D. In the event the total costs (construction and chattel improvements of the
Club are less than the deposits under Section 38 (A) (2) and (3), the Credit
under Section 38(B) (4) and the Advance under Section 38(B) (5), any excess
shall be paid to Landlord and the tenant under the Club lease as follows:

         1.     28.57% to such tenant
         2.     28.57% to Landlord
         3.     42.86% to Landlord to reduce the Advance.

E. In the event the Club Option is not exercised, the demised premises shall be
increased by 12,500 square feet on the Upper Lobby Level and decreased by
9,415.5 square feet on the 6th floor and 3,084.5 on the 5th floor. To the extent
the Club Option is exercised for more or less than 12,500 square fee the
increase or decrease shall first cause an adjustment to the area under this
Lease on the Upper Lobby floor (17,915.5 square feet) and then, floor 6 and/or
floor 5 shall be adjusted to maintain a total Rentable Area of the demised
premises of 100,000 square feet.

         39.      SECURITY AREA.

A. Notwithstanding Section 6(I) of this Lease, Tenant may, if Tenant complies
with Section (B) below, provide its own locks to an area within the demised
premises ("Secured Area") and shall not be required to furnish Landlord with a
key, except upon termination of this Lease Tenant shall surrender such keys to
Landlord. If Landlord determines, in its sole discretion, that an emergency or
other situation in the Building, or the demised premises exists, including, by
way of

                                       37
<PAGE>

explanation but not limitation, any suspected fire or flood, Landlord may
forcibly enter the Secured Area. In such event, Landlord shall have no liability
whatsoever to tenant, and Tenant shall pay all reasonable expenses incurred by
Landlord in repairing or reconstructing any entrance, corridor, or door or other
portions of the demised premises or the Secured Area damaged as a result of
Landlord's forcible entry, provided however, Landlord shall use reasonable
efforts to contact a representative of Tenant to secure access to the Secured
Area prior to a forcible entry but under no circumstances shall Landlord be
obligated to contact Tenant. Landlord shall have no obligation to provide either
janitor service or cleaning in the Secured Area.

B. On or before thirty (30) days prior to Tenant's occupancy of the demised
premises, Tenant shall give notice to Landlord showing the Secured Area and the
name and manner of contact of a representative of Tenant to be contacted to
avoid a forcible entry as stated in Section (A) above.

         40.    BUILDING.

         Landlord agrees to maintain the Building and the corridors in the
public areas in a manner consistent with a first class downtown Chicago office
building.

         41.    QUIET ENJOYMENT.

         Landlord covenants and agrees that Tenant, upon paying the rental and
performing Tenant's other covenants and agreements under this Lease, shall and
may peacefully have and enjoy the demised premises for the term of this Lease
free and clear from hindrance by Landlord or any person claiming through
Landlord, subject always to the provisions of Section 15 and Exhibit "C" of the
Lease.

         42.    ANNUAL NOTICE.

A. Within sixty (60) days after December 31st of each calendar year during the
Lease term, Landlord shall advise Tenant of all leases made during such calendar
year on the lowest thirty-one (31) office floors of the Building and the ten
(10) lowest office floors of the Phase II Tower. Such notice shall include the
name of tenant, the term of the lease, the rental, options to renew or expand,
and a demising plan showing the options to renew or expand, and a demising plan
showing the space and square footage. The aforementioned advisement is for
information only and shall not be deemed to confer any rights to Tenant or
Members on such floors except as provided in this Lease.

                                       38
<PAGE>

B. Upon written request of Tenant, Landlord shall advise as to whether a tenant
has exercised an option contained in its lease or whether a given space has been
leased.

         43.    DESIGN CHANGES.

         The Rentable Area of the Building (Section 2(a) (vii)), Rental Area of
the demised premises (Section 2(a) (viii)) and the Exhibits A-1 through A-6 will
change as a result of design changes and refinement by Landlord's architect,
Fujikawa Conterato Lohan and Associates, Inc. When such has been completed, and
the Rentable Area of the premises and Building certified by such architect, this
Lease shall be amended to reflect the certified areas as follows;

A. Annual Base Rent (Section 1) rate per square foot of $19.75 (or $20.25),

B. Tenant's Proportion (Section 2(a) (xi)),

C. Taxes and Expense Rent Adjustment (Section 2(d)) at the rate of $5.50 per
square foot of Rentable Area of the Building,

D. Rent Credit (Section 31(A))

         1. Column A at $19.75 multiplied by the Rentable Area of the demised
         premises and

         2. Column B at $20.25 multiplied by the Rentable Area of the demised
         premises,

E. Replacement Exhibits A-1 through A-6, as required,

F. Rentable Area of the Building (Section 2(a) (vii)),

G. Rentable Area of the demised premises (Section 2(a) (viii)).

         44.    SINGLE DIGIT ADDRESS.

         Supplementing the provisions of Section 16(a), but not in derogation
thereof, Landlord shall use reasonable efforts to obtain a single digit address
for the Building such as "4" South Wacker Drive.

         45.    SHOPS.

         Landlord shall use reasonable efforts to lease retail

                                       39
<PAGE>

space in the Building for a bank, newsstand, tobacco shop, public restaurant and
bar overlooking the Chicago river, drug store and men's and women's soft goods
stores.

         46.    LEASE CONFLICT.

         In the event a conflict develops between this Lease and the Members
Lease Forum, this Lease shall prevail.

         47.    MEMORANDUM OF LEASE.

         Landlord and Tenant agree to execute the Memorandum of Lease (Exhibit
"E") which may be recorded by Tenant.

         48.    INFORMATION KIOSK.

         It is understood that Tenant may be desirous of installing an
information kiosk ("Kiosk") of approximately forty (40) square fee ton the plaza
level of the Building. Landlord hereby agrees to use all reasonable efforts to
aid Tenant in achieving such desire (if achieved, the Kiosk space shall be added
to the demised premises) provided however, Tenant agrees to accept the provided
space in its condition occurring on the data it is tendered to Tenant, it being
understood that the Kiosk will not or may not be enclosed with demising walls.
The plans, specifications, method of installation and location of the Kiosk are
subject to approval by Landlord and any governmental agency having jurisdiction,
and all costs and expenses, including costs of construction materials and labor,
design and investigations shall be the sole responsibility of Tenant. There
shall be no Base Rent or Rent Adjustment charges for the Kiosk.

         49.    INSTALLATION OF ELEVATOR SHAFT AND ELEVATOR.

         It is understood that Tenant may be desirous of installing an elevator
shaft and elevator ("Elevator") for Tenant's private freight elevator usage
between the P-1 Level and Mechanical Level #2 of the Building. Landlord hereby
agrees to provide the Elevator at Landlord's sole cost and expense. The plans,
specifications, method of installation and location of the Elevator shall be
established by Landlord's architect. There shall be no rental charged for the
Elevator.

         50.    DOCK RECEIVING OFFICE.

         It is understood that Tenant may be desirous of sharing a dock
receiving office ("Office") on the P-1 Level of the Building with Landlord.
Landlord hereby agrees to use all reasonable efforts to aid Tenant in achieving
such desire.

                                       40
<PAGE>

The nature and location of the Office is subject to approval by Landlord. The
costs and expenses incurred for the Office shall be shared by Landlord and
Tenant. The Rental for the Office is subject to the mutual agreement of Landlord
and Tenant.

         51.    STORAGE SPACE.

         It is understood that Tenant may be desirous of acquiring up to 150
square feet of storage space ("Storage Space") on the P-1 level near the Office.
Landlord hereby agrees to use all reasonable efforts to aid Tenant in achieving
such desire (if achieved the Storage Space shall be added to the demised
premises except that section 3(a) shall not apply). The plans, specifications,
and location of the Storage Space are subject to the approval of Landlord and
all costs and expenses incurred are the sole responsibility of Tenant. Rental
charges for the Storage Space are subject to the mutual agreement of Landlord
and Tenant.

         52.    MECHANICAL SPACE.

         It is understood that Tenant may be desirous of acquiring space (not to
exceed 4,000 square fee) for their chiller and vertical condenser water riser
("Mechanical Space") in the core of the Building. Landlord hereby agrees to use
all reasonable efforts to aid Tenant in achieving such desire (if achieved the
Mechanical Space shall be added to the demised premises except that section 3(a)
shall not apply). The plans, specifications, method of installation and location
of the Mechanical Space are subject to the approval of Landlord and any
governmental agency having jurisdiction, and all costs and expenses, including
costs of construction materials and labor, investigations, incurred as a result
of such installation, are the sole responsibility of Tenant. There shall be no
Base Rent or Rent Adjustment charges for the Mechanical Space.

         53. AS-BUILTS.

         Tenant may review as-built plans in Landlord's possession for any space
to which Tenant or Members may have rights.

         54.    ADDITIONAL AND CONSTANT PORTION LIMITATION.

A. Tenant need not pay the Additional Portion and/or Constant Portion (or
portion thereof) for any Year during the Lease term to the extent the Additional
Portion Rate Per Square Foot plus the Constant Portion Rate Per Square Foot for
such Year when added to the sum of:

                  Base Rent Rate Per Square Foot
                  Tax and Expense portion of the Rent Adjustment
                          Rate Per Square Foot
                  Base Portion Rate Per Square Foot

                                       41
<PAGE>

causes the resulting total for such Year during the Lease term to exceed the
Prevailing Market Rate Per Square Foot.

B. Under no circumstances shall this Section 54 be construed to limit the
obligation of Tenant to pay the total of:

                  Base Rent
                  Tax and Expense Rent Adjustment
                  Base Portion

C. For purposes of this Section 54, "Year" means a calendar year (January 1
through December 31).

Section 10 continued;

         10A. If the demised premises or Building are damaged by fire or other
casualty during a time when a mortgagee, a trustee under a trust deed, or a
purchaser at a foreclosure sale is the owner of the Real Property after a
default under the mortgage or trust deed and shall be the Landlord hereunder
(hereafter in this Section 10A referred to as the "Post Default Owner"), and if
(a) the damage caused by such fire or other casualty exceeds an amount equal to
fifteen percent (15%) of the then current insurable value of the Building and
(b) the Trading Floor has not been damaged or, if it has, Tenant gives Post
Default Owner notice that (i) if the damage to the Trading Floor exceeds thirty
percent (30%) of the insurable value thereof, owner of the Trading Floor desires
to reconstruct the Trading Floor or (ii) if the damage to the Trading Floor is
thirty percent (30%) or less of the insurable value thereof, owner of the
Trading Floor will reconstruct the Trading Floor, or if Tenant fails to give
such notice within sixty (60) days after such fire or casualty, then provisions
of this Section 10A shall apply.

                In the event the conditions stated above in this Section 10A
occur, Post Default Owner shall, within sixty (60) days after the last to occur
of (a) a determination of the then current insurable value of the Building, or
(b) the receipt of any required notice from Tenant that owner of the Trading
Floor desires to or will reconstruct the Trading Floor, elect either;

                (i) to serve notice on Tenant that Post Default Owner will
proceed with all due diligence to repair, restore or rehabilitate the Building
or the demised premises at Post Default Owner's expense, in which event the
provisions of Section 10 set forth in the last paragraph thereof shall apply, or

                (ii) to serve notice on Tenant that Post Default Owner does not
intend to make the election described in clause (i) above and chooses to retain
for its own use and property the insurance proceeds payable by reason of such
fire or other casualty.

If Post Default Owner shall make the election in clause (ii) above, Tenant shall
have an option (exercisable by written notice to Post Default Owner within Sixty
(60) days after receipt by Tenant of the notice described in clause (ii)) to
purchase the Real Property from Post Default Owner at a price equal to the fair
market value of the Real Property in its unrepaired condition. Such purchase
shall be for cash less the amount of any existing mortgage encumbrances to which
title will be subject at closing. If the amount of existing mortgage
encumbrances exceeds the fair market value of the Real Property in its
unrepaired condition, then Post Default Owner shall pay to Tenant or the
encumbrancer the amount of such excess at closing. If Post Default Owner and
Tenant are unable to agree on the fair market value of the Real Property within
a period of sixty (60) days after the date of receipt of Post Default Owner's
notice by Tenant, then the fair market value of the Real Property shall be
determined by an appraiser selected jointly by Post Default Owner and Tenant.
The determination of such appraiser shall be conclusive upon the parties. The
expenses of such appraisal shall, except as hereinafter provided, be shared
equally by Post Default Owner and Tenant. If an appraisal of the Real Property
is made, Tenant shall have the right to withdraw its offer to purchase the Real
Property within sixty (60) days after the determination of fair market value by
the appraiser. If Tenant withdraws its offer, Tenant shall pay all of the
expenses of the appraiser. The closing shall be not later than one hundred
twenty (120) days after agreement as to determination of the fair market value.

                                       42
<PAGE>

(continuation of 2.a.xiii)

The parties hereto acknowledge that the title holder of the Phase II Tower may
hereafter be an entity or person other than the initial Landlord and all
references in this Lease to the Phase II Tower are set forth for the purpose of
identifying the rights of Tenant with respect to the Phase II Tower and binding
the owners thereof from time to time to the obligations with respect to the
Phase II Tower set forth in this Lease. It is further acknowledged by the
parties hereto that the obligations of any Post Default Owner (defined in
section 10.A.) of the Real Property with respect to the Phase II Tower are
subject to and contingent upon the direct or indirect ownership by such Post
Default Owner of the Phase II Tower and such Post Default Owner shall have no
obligations and shall not be deemed to have made any warranties with respect to
the Phase II Tower except at such times as such Post Default Owner is the direct
or indirect owner of the Phase II Tower. If and so long as Post Default Owner
has to direct or indirect ownership of the Phase II Tower, as to such Post
Default Owner only, this Lease will be construed as deleting all references to
the Phase II Tower.

                                     42(a)
<PAGE>

                                                                      4/14/81

The following example is provided to show the method by which the CPI Portion of
the Rent Adjustment will be calculated for the years listed based upon the
assumptions stated.

         Assumptions -     Base Rent - $20.25/s.f.
                        -  CPI Increase at a Constant 10%/Year
                        -  Commencement Date of Lease 1/1/84

<TABLE>
<CAPTION>
   (1)        (2)           (3)         (4)                (5)              (6)             (7)               (8)          (9)
                                                                                                           "Constant
                                                                         CPI Factor                        Portion"     "CPI Portion
                                                                         @ 10% or 6%                       (Addt'l        of Rent
                                                                         Cap Factor                        Portion       Adjustment"
                         CPI Factor  "Base             30% of Prior     whichever is    "Additional        For 1993       (Col 4
Calendar    30% of       @ 10% For   Portion"          Year CPI         Less Starting   Portion"           Remains        + Col 7
Year (D)    $20.25       19 Yrs.     (Col 2 x Col 3)   (30% x Col 9)    Over in 1994    (Col. 5 x Col 6)   Constant       + Col 8)
--------    ------       -------     ---------------   -------------    ------------    ----------------   --------     ------------
<S>         <C>          <C>         <C>               <C>              <C>             <C>                <C>          <C>
1984 (A)    $6.075/sf         -            0                 0                -               0                  0            0
1985           6.075          -            0                 0                -               0                  0            0
1986           6.075          -            0                 0                -               0                  0            0
1987 (B)       6.075       .331        $2.01/sf              0            .191016             0                  0      $   2.01/sf
1988           6.075       .464          2.82            $   .60/sf       .262477         $     .16/sf           0          2.98
1989           6.075       .611          3.71                 .90         .338226                .31             0          4.02
1990           6.075       .772          4.69                1.21         .418519                .51             0          5.20
1991           6.075       .949          5.77                1.56         .503630                .79             0          6.56
1992           6.075      1.144          6.95                1.97         .593818               1.18             0          8.13
1993 (C)       6.075      1.358          8.25                2.44         .689479               1.70             0          9.95
1994           6.075      1.594          9.68                2.99         .060000                .18        $   1.70       11.56
1995           6.075      1.853         11.26                3.47         .123600                .43            1.70       13.39
1996           6.075      2.138         12.99                4.02         .191016                .78            1.70       15.47
1997           6.075      2.452         14.90                4.65         .262477               1.23            1.70       17.83
1998           6.075      2.797         16.99                5.35         .338226               1.82            1.70       20.51
1999           6.075      3.177         19.30                6.16         .418519               2.60            1.70       23.60
2000           6.075      3.595         21.84                7.08         .503630               3.59            1.70       27.13
2001           6.075      4.054         24.63                8.14         .593848               4.87            1.70       31.20
2002           6.075      4.560         27.70                9.36         .689479               6.50            1.70       35.90
2003           6.075      5.116         31.08               10.77         .790848               8.58            1.70       41.36
</TABLE>

NOTES:
(A) Calendar Year in which Commencement Date Occurs.
(B) Calendar Year in which 37th Month of Lease Term Occurs.
(C) Calendar Year in which 120th Month of Lease Term Occurs.
(D) Calendar Years are the same as Calculation Years, so Proration Need Not
    Occur

                                      43
<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Lease the
date first above written.

                                       LANDLORD

               AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, ILLINOIS,
               a national banking association of Chicago, Illinois, not
ATTEST:        individually but solely as Trustee under the provisions of a
               certain Trust Agreement dated March 20, 1980,
               and known as Trust No. 48268.

By _____________________________            By _________________________________
Its      ASSISTANT SECRETARY                Its          TRUST OFFICER

ATTEST:                                 TENANT
                            CHICAGO MERCANTILE EXCHANGE
                        an Illinois not-for-profit corporation

By _____________________________            By _________________________________
Its      Vice President                     Its      CHAIRMAN OF THE BOARD

                                       44
<PAGE>

                            FIRST AMENDMENT TO LEASE
                            ------------------------

        This First Amendment to Lease is made and entered into as of this 1st
day of February, 1982, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY
OF CHICAGO, not individually but solely as Trustee under the provisions of a
certain Trust Agreement dated March 20, 1980, and known as Trust No. 48268
("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois not-for-profit
corporation ("Tenant").

                                  WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a certain Agreement of Lease
dated May 11, 1981 (hereinafter called "Lease), pursuant to which Landlord
leased to Tenant, and Tenant leased from Landlord 100,000 square feet of office
space on the Lobby Level and 2nd-6th Floors of the building located at 30 South
Wacker Drive, Chicago, Illinois (hereinafter called the "Building"); and

        WHEREAS, Landlord and Tenant desire to enter into this First Amendment
to Lease for the purpose of amending the Lease as hereinafter set forth;

        NOW, THEREFORE, for a good and valuable consideration, the receipt and
sufficiency whereof being hereby acknowledged, Landlord and Tenant hereby agree
as follows:

             1.   Section 2 of the Lease and Section 2 of Exhibit "F" of the
Lease (Member Lease) are amended-

                  a.   by striking out "993,040" in line 1 of subsection
             2(a)(vii) and inserting in lieu thereof "1,029,127"; and

                  b. by striking out "$5,461,720.00" in line 2 of subsection
             2(d) and inserting in lieu thereof "$5,660,199.00"; and

                  c. by striking out "1977" both times it appears in subsection
             2(h) and inserting in lieu thereof "1967".

             2. Section 2 of the Lease is amended -

                  a.   by striking out "10.070" in line 1 of subsection 2(a)(xi)
             and inserting in lieu thereof "9.717"; and

                                       1
<PAGE>

                  b. by adding at the end of subsection 2(a) thereof the
             following:

             (xxxii)   "Member(s)" means any of the following:

                  A.   an individual who is a member in good standing of Tenant;

                  B.   an entity (corporation or partnership) who:

                       1.    has at least two (2) Chicago Mercantile Exchange
                       seats assigned to it, or

                       2.    has at least two (2) International Monetary Market
                       seats assigned to it, or

                       3.    has at least two (2) Associate Mercantile Market
                       seats assigned to it, or

                       4.    has at least two (2) Index/Options Market seats
                       assigned to it, or

                       5. has been approved by Tenant as Class B Clearing
                       Member.

             (Note:  The International Monetary Market, Associate Mercantile
             Market and the Index/Options Market are divisions of Tenant.)

             2. Section 24 of the Lease and Section 24 of Exhibit "F" of the
Lease (Member Lease) are amended by adding at the end of Section 24 thereof the
following:

                  (v) The liability or obligations of Metropolitan Structures
                  under this Lease, if any, shall be limited to its partnership
                  assets and no partner of said partnership shall be
                  individually or personally liable for any claim arising out of
                  this Lease. A deficit capital account of any such partner
                  shall not be deemed an asset or property of said partnership.

                  (w) The liability or obligations of JMB/MS Management Co.
                  under this Lease, if any, shall be limited to its partnership
                  assets and no partner of said partnership shall be
                  individually or personally liable for any claim arising out of
                  this Lease. A deficit capital account of any such partner
                  shall not be deemed an asset or property of said partnership.

             3. Section 25 of the Lease is amended -

                  a.   by striking out subsection 25A.1 and inserting in lieu
             thereof the following:

             25.A.1. Landlord agrees to reserve ("Reservation") approximately
             400,000 square feet including the demised premises ("First
             Reservation Space") on the lowest office floors of the Building for
             lease to Tenant and Members. The Reservation shall terminate at
             midnight, April 30, 1982, unless 300,000 square feet (including the
             demised premises) is leased by Tenant and/or Members on or before
             April 30, 1982, under which circumstances the Reservation shall be
             deemed automatically extended until midnight, October 31, 1982.

                                       2
<PAGE>

                  b. by inserting the following before the period in line 12 of
             subsection 25B.2.a.:

             (in order to achieve such contiguity, it is understood that Tenant,
             at its sole expense, may among other things, change the demised
             premises of a Member after a lease with such Member has been
             completely executed even though the change results in a change in
             the size, location and/or configuration of such demised premises)

             4. The Work Letter attached to the Lease and the Work Letter
attached to Exhibit "F" (Member Lease) are amended by adding at the end of
Section V thereof the following:

                  I. The liability or obligations of Metropolitan Structures
                  under this Work Letter, if any, shall be limited to its
                  partnership assets and no partner of said partnership shall be
                  individually or personally liable for any claim arising out of
                  this Work Letter. A deficit capital account of any such
                  partner shall not be deemed an asset of said partnership.

                  J. The liability or obligations of Metco Properties under the
                  Lease or this Work Letter, if any, shall be limited to its
                  partnership assets and no partner of said partnership shall be
                  individually or personally liable for any claim arising out of
                  the Lease or this Work Letter. A deficit capital account of
                  any such partner shall not be deemed an asset of said
                  partnership.

             5. Attachment "A" of the Work Letter attached to the Lease and page
40 of Exhibit "F" (Attachment "A" to the Member Lease) are amended - a.   by
striking out "200" in item 9 and inserting in lieu thereof "175"; and b. by
striking out "250" in item 10 and inserting in lieu thereof "218.75".

             6. Section 2.a.xxx. of Exhibit "F" of the Lease (Member Lease) is
amended by inserting the following after "1981" in line 1: ", as amended from
time to time,".

                                       3
<PAGE>

             7. Section 32 of Exhibit "F" of the Lease (Member Lease) is amended
by the addition of the following:

        Additionally, it is understood that the demised premises under this
        Lease may be changed by Landlord, at the request of the Chicago
        Mercantile Exchange (tenant under the Merc Lease), even though the
        change results in a change in the size, location and/or configuration of
        the demised premises. Tenant hereby agrees to execute promptly all
        amendatory documents to this Lease required to reflect any such change.
        Such documents may include changes in the following:

                  1.   Size of the demised premises.
                  2.   Base Rent.
                  3.   Proportion.
                  4.   Credits.
                  5.   Location in the Building.

        In any event any such change is made, any expenses resulting therefrom
        shall be the responsibility of the Chicago Mercantile Exchange or
        Tenant.

             8. The letter agreement of August 26, 1981, a copy of which is
attached hereto and marked as Exhibit "1", is hereby rendered null and void.

             9. Section 44 of the Lease to the contrary notwithstanding, 30
South Wacker Drive, Chicago, Illinois, is the address preferred by Tenant for
the south office tower of the Building and such address, subject to Section
16(c) of the Lease, is hereby established as the address for such tower.

             10. The Demising Plans of the Lease are amended -

                  a. by striking out "17,915.5" on Exhibit A-1 (Upper Lobby
               Level) and inserting in lieu thereof "19,078";

                  b. by striking out "16,490" on Exhibit A-2 (2nd Floor Plan)
               and inserting in lieu thereof "17,884";

                  c. by striking out "17,310" on Exhibit A-3 (3rd Floor Plan)
               and inserting in lieu thereof "17,022";

                  d. by striking out "18,636" on Exhibit A-4 (4th Floor Plan)
               and inserting in lieu thereof "18,746";

                  e. by striking out "20,233" on Exhibit A-5 (5th Floor Plan)
               and inserting in lieu thereof "20,627"; and

                  f. by striking out "9,415.5" on Exhibit A-6 (6th Floor Plan)
               and inserting in lieu thereof "6,643".

                                       4
<PAGE>

             11. Section 38 E. of the Lease is amended -

                  a. by striking out "9,415.5"in line 2 and inserting in lieu
             thereof "6,643";

                  b. by striking out "3,084.5" in line 3 and inserting in lieu
             thereof "5,857"; and

                  c. by striking out "17,915.5" in line 6 and inserting in lieu
             thereof "19,078".

             12. Wherever the works "METROPOLITAN STRUCTURES INC." appear in the
Lease or any exhibit or attachment thereto such shall be deemed amended to refer
to "METROPOLITAN STRUCTURES, a General Partnership".

             13. Except as hereinbefore modified or amended, the provisions,
conditions and terms of the Lease shall remain unchanged and in full force and
effect.

             IN WITNESS WHEREOF, the parties hereto have executed this First
Amendment to Lease as of the date first above written.

                                                  LANDLORD

                               AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                               CHICAGO, ILLINOIS, a national banking association
                               of Chicago, Illinois, not individually but solely
                               as Trustee under the provisions of a certain
                               Trust Agreement dated March 20, 1980, and known
                               as Trust No. 48268.

ATTEST:                             By              /s/
                                      ----------------------------------
                                    Its          Vice President

By              /s/
  -------------------------------
Its     Assistant Secretary

                                                   TENANT

                                CHICAGO MERCANTILE EXCHANGE, an Illinois
                                not-for-profit corporation

ATTEST:                             By              /s/
                                      ----------------------------------
                                    Its          Vice President

By              /s/
  -------------------------------
Its  Secretary to Vice President

                                       5
<PAGE>

                            SECOND AMENDMENT TO LEASE
                            -------------------------

        This Second Amendment to Lease is made and entered into as of this 26th
day of April, 1982, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not individually but solely as Trustee under the provisions of a
certain Trust Agreement dated March 20, 1980, and known as Trust No. 48268
("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois not-for-profit
corporation ("Tenant").

                                  WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a certain Agreement of Lease
dated May 11, 1981 pursuant to which Landlord leased to Tenant, and Tenant
leased from Landlord 100,000 square feet of office space on the Lobby Level and
2nd - 6th Floors of the Building located at 30 South Wacker Drive, Chicago,
Illinois (hereinafter called the "Building"); and a First Amendment to Lease
dated February 1, 1982 (hereinafter collectively referred to as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Second Amendment
to Lease for the purposes of amending the Lease is hereinafter set forth;

        NOW THEREFORE, for a good and valuable consideration, the receipt and
sufficiency whereof being hereby acknowledged, Landlord and Tenant hereby agree
as follows:

             I.   Effective May 1, 1982:

A. Section 2(a) (vii) is amended by striking out "1,029,127" in line one (1) and
inserting in lieu thereof "1,030,981";

B. Section 2(a)(viii) is amended by striking out "100,000" in line one (1) and
inserting in lieu thereof "160,208". (Such change in the size of the demised
premises results from a change on the Upper Lobby Level and the 6th floor
(Sections D and E below) and by the addition of 47,297 square feet on the 7th
and 8th floors of the Building ("First Additional Space") as shown on Exhibits
"A-7a", "A-7b" and "A-8" attached hereto.);

C. Section 2(d) is amended by striking "$5,660,199.00" in line two (2) and
inserting in lieu thereof "$5,670,396.00";

D. Exhibit A-1 (Upper Lobby Level) is deleted and replaced by "New Exhibit A-1"
attached hereto;

E. Exhibit A-6 (6th Floor Plan) is deleted and replaced by "New Exhibit A-6"
attached hereto;

                                       1
<PAGE>

F. the First Additional Space shall be considered demised premises subject to
terms and conditions of the Lease;

G. Section 2(a) (xi) is amended by striking "10.070" and inserting in lieu
thereof "15.54";

H. Tenant is deemed to have exercised the Work Option (Section 29) therefore
Column "A" for Tenant is stricken from Section 31.A.;

I. until the day before the tenth (10th) Anniversary 40,208 square feet of the
demised premises is deemed to be Second Reservation Space ("Second Space") so
that the following applies to the Second Space;

        1. annual Base Rent rate per square foot is $25.00 (reflected in Section
        III below):

        2. the Tax and Expense Rent Adjustments are as stated in the Lease;

        3. the CPI portion of the Rent Adjustment is forty percent (40%) instead
        of thirty percent (30%) so that Section 2(a) of the Lease is changed as
        follows:

             (xxi) line 2 - 30% changes to 40%
             (xxi) line 7 - 30% changes to 40%
             (xxii)1(a) line 5 - 30% changes to 40%
             (xxii)1(a) line 9 - 30% changes to 40%
             (xxii)2(a) line 6 - 30% changes to 40%
             (xxii)2(a) line 12 - 30% changes to 40%

        4. the CPI portion of the Rent Adjustment commences on the first (1st)
        day of the thirteenth (13th) month of the Lease term so that Section
        2(b) is changed as follows:

             line 2 - 37th is changed to 13th;

             line 5 - 37th is changed to 13th;

             line 7 - 37th is changed to 13th.

        5. the Work Option under Section 29 of the Lease is deemed exercised;
        and

        6. the Second Space is not included to determine the amount of Five, Ten
        or Fifteen Year Space.

        7. Landlord shall provide Tenant a calculation of the CPI portion of the
        Rent Adjustment for the Second Space separate from such calculation for
        the remainder of the demised premises.

             II.  Effective on the tenth (10th) Anniversary, as to the Second
Space:

A. annual Base Rent rate per square foot is $20.25 (reflected in Section III
below);

B. the Tax and Expense Rent Adjustments are as stated in the Lease; and

                                       2
<PAGE>

C. the CPI portion of the Rent Adjustment is thirty percent (30%) so that
Section 2(a) is changed as follows:

        (xxi) line 2 - 40% changes to 30%
        (xxi) line 7 - 40% changes to 30%
        (xxii)1(a) line 5 - 40% changes to 30%
        (xxii)1(a) line 9 - 40% changes to 30%
        (xxii)2(a) line 6 - 40% changes to 30%
        (xxii)2(a) line 12 - 40% changes to 30%

D. The Additional Portion (Section 2(a) (xxii)) and the Constant Portion
(Section 2(a) (xxiii)) shall be calculated as though the Second Space was added
to the demised premises on May 1, 1982 as First Reservation Space.

             III. The total Base Rent of $39,500,001.60 payable as set forth in
Section 1 of the Lease is amended to be a total Base Rent of $66,794,120.40 as
set forth in said Section 1 of the Lease except that it shall be payable as
follows:

A. 120 equal monthly installments of $286,266.67 to be paid in advance on or
before the first day of each month during the period beginning on the
Commencement Date and ending on the day before the tenth (10th) Anniversary; and

B. 120 equal monthly installments of $270,351.00 to be paid in advance on or
before the first day of each month during the period beginning on the tenth
(10th) Anniversary and ending on the Termination Date.

             IV.  Section 25 of the Lease is amended;:

A. by striking out "April 30, 1982" in lines 6 and 8 of Section 25.A.1. and
inserting in lieu thereof "May 31, 1982"; and

B. by striking out "200,000" in line 3 of Section 25.A.2. and inserting in lieu
thereof "159,792".

             V.   Section 26 of the Lease is amended:

A. by striking out "twenty percent (20%) of the Tenant's demised premises leased
prior to the expiration of the Reservation" in Section 26.A. and inserting in
lieu thereof "24,000 square feet";

B. by striking out "twenty percent (20%) of the Tenant's demised premises leased
prior to the expiration of the Reservation" in Section 26.B. and inserting in
lieu thereof "24,000 square feet"; and

C. by striking out "twenty percent (20%) of the Tenant's demised premises leased
prior to the expiration of the Reservation" in Section 26.C. and inserting in
lieu thereof "24,000 square feet"; and

D. Section E.1. is deleted and replaced with:

             "1.  on floors above the demised premises within space leased by
Members (sites to be selected by Tenant),

                                       or"

                                       3
<PAGE>

             VI.  Section 29.B.2. of the Lease is amended by adding ", excluding
the Second Space," after the first "premises" in line 2.

             VII. Section 31.A. of the Lease is amended:

A. by adding ", as to Tenant, Second Space is deemed excluded from this
calculation" after the word "premises" in line 3;

B. by adding ", except Second Space," after the word "Tenant" in line 4; and

C. by striking and deleting the following:

        "                                Column A       Column B
        Month                             Amount         Amount
        -----                             ------         ------
        For 2nd month of Lease term    $164,583.34    $168,750.00
        For 3rd month of Lease term    $164,583.34    $168,750.00
        For 4th month of Lease term    $164,583.34    $168.750.00
                                       -----------    -----------
                  Total                $493,750.02    $506,250.00"

and inserting the following in lieu thereof:

        "                                           Column B
        Month                                        Amount
        -----                                        ------
        For 2nd month of Lease term                $202,500.00
        For 3rd month of Lease term                $202,500.00
        For 4th month of Lease term                $202,500.00
                                                   -----------
                  Total                            $607,500.00".

             VIII. Section 33.B. of the Lease is amended by adding ", except
Second Space," after the word "premises" in line one of the formula at the top
of page 33.

             IX.  Section 38 of the Lease is amended:

A. by striking out "approximately 12,500" in line 3 of Section 38.A. and
inserting in lieu thereof "13,643"; and

B. by striking "(Exhibit A-1" in line 4 of Section 38.A. and inserting in lieu
thereof "(Exhibit A-1a" attached hereto; and

C. by striking out "$232,000.00" in line 2 of Section 38.A.2. and inserting in
lieu thereof "$253,214.00"; and

D. by striking out "$463,000.00" in line 2 of Section 38.A.3. and inserting in
lieu thereof "$505.337.00"; and

E. by striking out the first sentence in Section 38.B.1. in its entirety and
replacing in lieu thereof the following:

        "1. A lease on the Members Lease Form for a twenty (20) year term (with
no Work Letter and no Attachment "A") shall be prepared to reflect total Base
Rent of SIX MILLION EIGHT HUNDRED TWENTY-ONE THOUSAND FIVE HUNDRED AND 80/100
DOLLARS ($6,821,500.80) payable in two hundred forty (240) monthly installments
of TWENTY EIGHT THOUSAND FOUR HUNDRED TWENTY-TWO AND 92/100 ($28,422.92)."

                                       4
<PAGE>

F. by striking out "$463,000.00" in line 2 of Section 38.B.4. and inserting in
lieu thereof "$505,337.00"; and

G. by striking out $695,000.00" in line 3 of Section 38.B.5.(a) and inserting in
lieu thereof "$758,551.00"; and

H. by striking out "or" in line 6 of Section 38.B.5.(a) and inserting in lieu
thereof "of"; and

I. by striking and deleting Section 38.E. in its entirety.

             X.   Section 43 is amended:

A. by adding "or $25.00 for Second Space" after "$20.25" in line 2 of Section
43.A.; and

B. by adding "(excepting Second Space)" after "premises" in line 2 of Section
43.D.1.

C. by adding "(excepting Second Space)" after "premises" in line 2 of Section
43.D.2.

             XI.

             SECURITY DEPOSIT. Tenant agrees to deposit with Landlord, upon the
execution of this Second Amendment the sum of $15,915.67 as security for the
full and faithful performance by Tenant of each and every term, provision,
covenant, and condition of this Lease. If Tenant defaults in respect to any of
the terms, provisions, covenants and conditions of this Lease including, but not
limited to, payment of the Base Rent, Rent Adjustment Deposits or Rent
Adjustments, Landlord may use, apply, or retain the whole or any part of the
security so deposited for the payment of any such Base Rent, Rent Adjustment
Deposits or Rent Adjustments in default, or for any other sum which Landlord may
expend or be required to expend by reason of Tenant's default including, without
limitation, any damages or deficiency in the reletting of the demised premises,
whether such damages or deficiency shall have accrued before or after any
re-entry by Landlord. If any of the security shall be so used, applied or
retained by Landlord, at any time or from time to time, Tenant shall promptly,
in each such instance, on written demand therefor by Landlord, pay to Landlord
such additional sum as may be necessary to restore the security to the original
amount set forth in the first sentence of this paragraph. If Tenant shall fully
and faithfully comply with all the terms, provisions, covenants, and conditions
of this Lease, the security, shall be applied, at Tenant's written request,
against the monthly installment due on the 11th Anniversary. If not so requested
then the security or any balance thereof, shall be returned to Tenant after the
following:

             (a) the time fixed as the expiration of the term of this Lease;

             (b) the removal of Tenant from the demised premises;

             (c) the surrender of the demised premises by Tenant to Landlord in
accordance with this Lease; and

             (d) the time required for all Rent Adjustments owned pursuant to
the Lease to have been computed by Landlord and paid by Tenant.

             Except as otherwise required by law. Tenant shall not be entitled
to any interest on the aforesaid security. In the absence of evidence
satisfactory to Landlord of any assignment of the right to receive the security
or the remaining balance thereof, Landlord may return the security to the
original Tenant, regardless of one or more assignments of this Lease.

             XII.

A. Exhibit A-2 is deleted and replaced by "New Exhibit A-2" attached hereto;

B. Exhibit A-3 is deleted and replaced by "New Exhibit A-3" attached hereto;

                                       5
<PAGE>

C. Exhibit A-4 is deleted and replaced by "New Exhibit A-4" attached hereto; and

D. Exhibit A-5 is deleted and replaced by "New Exhibit A-%" attached hereto;

             XIII.Item 14 of Attachment "A" of the Work Letter attached to the
Lease is amended by adding:

A. "4" between 3 and 5, and

B. "11" after 10.

             XIV. The letter dated April 16, 1982 attached hereto (Exhibit "B")
is hereby deemed null and void.

             XV. Except as hereinbefore modified or amended, the provisions,
conditions and terms of the Lease shall remain unchanged and in full force and
effect.

        IN WITNESS WHEREOF, the parties hereto have executed this Second
Amendment to Lease as of the date first above written.

                                                    LANDLORD

                                     AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                     CHICAGO, ILLINOIS, a national banking
                                     association of Chicago, Illinois, not
                                     individually but solely as Trustee under
                                     the provisions of a certain Trust Agreement
                                     dated March 20, 1980, and known as Trust
                                     No. 48268.

ATTEST:                             By           /s/
                                      ----------------------------------
                                    Its          Vice President

By            /s/
  ------------------------------
Its    Assistant Secretary

                                                     TENANT

                                     CHICAGO MERCANTILE EXCHANGE, an Illinois
                                     not-for-profit corporation

ATTEST:                             By              /s/
                                      ----------------------------------
                                    Its          Vice President

By             /s/
  ------------------------------
Its    A.A.

                                       6
<PAGE>

                            THIRD AMENDMENT TO LEASE
                            ------------------------

        This Third Amendment to Lease is made and entered into as of this 29th
day of June, 1982, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not individually but solely as Trustee under the provisions of a
certain Trust Agreement dated March 20, 1980, and known as Trust No. 48268
("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois not-for-profit
corporation ("Tenant").

                                  WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a certain Agreement of Lease
dated May 11, 1981 pursuant to which Landlord leased to Tenant, and Tenant
leased from Landlord 100,000 square feet of office space on the Lobby Level and
2nd-8th Floors of the Building located at 30 South Wacker Drive, Chicago,
Illinois (hereinafter called the "Building"); a First Amendment to Lease dated
February 1, 1982; and a Second Amendment to Lease dated April 26, 1982
(hereinafter collectively referred to as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Third Amendment
to Lease for the purposes of amending the Lease is hereinafter set forth;

        NOW THEREFORE, for a good and valuable consideration, the receipt and
sufficient whereof being hereby acknowledged, Landlord and Tenant hereby agree
as follows:

             I.   TENANT'S CREDIT.

A. As a concession to Tenant, provided that Tenant is not in default under the
Lease, Landlord hereby grants Tenant a credit of $48,062.40 (160,208 X $0.30) to
be applied against the second and, if necessary, subsequent monthly installments
of Base Rent due under the Lease.

B. The balance of Base Rent and/or Rent Adjustments due for the second month of
the Lease term shall be paid as provided for in Section 1 and 2 of the Lease.

             II.  WORK LETTER.

A.The Work Letter attached to the Lease is amended:

        1.   by striking out "Agent, if Tenant has exercised the Work Option
        containing in Section 29 of the Lease," in line 1 of Section I.A. and
        inserting in lieu thereof "Tenant"; and

        2. by striking out "R M M, Inc." in line 6 of Section I.A. and inserting
        in lieu thereof "Space/Management Programs Inc.".

             III. LETTER AGREEMENT

        The letter dated May 17, 1982 attached hereto (Exhibit "1") is hereby
deemed null and void.

                                       1
<PAGE>

             IV. Except as hereinbefore modified or amended, the provisions,
conditions and terms of the Lease shall remain unchanged and in full force and
effect.

             IN WITNESS WHEREOF, the parties hereto have executed this Third
Amendment to Lease as of the date first above written.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:                           By              /s/
                                    ---------------------------------
                                  Its          Vice President

By             /s/
   ---------------------------
   Its   Assistant Secretary
                                  This instrument is executed by AMERICAN
                                  NATIONAL BANK AND TRUST COMPANY OF CHICAGO,
                                  not personally but solely as Trustee, as
                                  aforesaid. All the covenants and conditions to
                                  be performed hereunder by AMERICAN NATIONAL
                                  BANK AND TRUST COMPANY OF CHICAGO are
                                  undertaken by it solely as Trustee, as
                                  aforesaid and not individually, and no
                                  personal liability shall be asserted or be
                                  enforceable against AMERICAN NATIONAL BANK AND
                                  TRUST COMPANY OF CHICAGO by reason of any of
                                  the covenants, statements, representations or
                                  warranties contained in this instrument.

                                                TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

                                  By              /s/
                                    ---------------------------------
                                  Its     Senior Vice President

ATTEST:
By            /s/
   ---------------------------
   Its     Secretary
<PAGE>

                            FOURTH AMENDMENT TO LEASE
                            -------------------------

        This Fourth Amendment to Lease is made and entered into as of this 28th
day of July, 1982, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not individually but solely as Trustee under the provisions of a
certain Trust Agreement dated March 20, 1980, and known as Trust No. 48268
("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois not-for-profit
corporation ("Tenant").

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a certain Agreement of Lease
dated May 11, 1981 pursuant to which Landlord leased to Tenant, and Tenant
leased from Landlord 100,000 square feet of office space on the Lobby Level and
2nd-6th Floors of the Building located at 30 South Wacker Drive, Chicago,
Illinois (hereinafter called the "Building"); and a First Amendment to Lease
dated February 1, 1982; a Second Amendment to Lease dated April 26, 1982; a
Third Amendment to Lease dated June 29, 1982; and

        WHEREAS, Landlord and Tenant desire to enter into this Fourth Amendment
to Lease for the purposes of amending the Lease is hereinafter set forth;

        NOW THEREFORE, for a good and valuable consideration, the receipt and
sufficient whereof being hereby acknowledged, Landlord and Tenant hereby agree
as follows:

             I.   TITLE PAGE.

        The Title Page of the Lease is changed by deleting "100,000 Square Feet
on the Upper Lobby Level and 2nd-6th Floors" and inserting in lieu thereof
"160,784 Square Feet on the Upper Lobby Level and 2nd -8th Floors".

             II.  WITNESSETH.

        The Witnesseth Section of the Lease is changed by deleting in line 3,
"100,000 Square Feet on the Upper Lobby Level and 2nd-6th Floors" and inserting
in lieu thereof "160,784 Square Feet on the Upper Lobby Level and 2nd-8th
Floors".

             III. BASE RENT.

        The total Base Rent of $66,794,120.40 payable as set forth in Section 1
of the Lease is amended to be a total Base Rent of $67,027,400.40 as set forth
in said Section 1 of the Lease except that it shall be payable as follows:

        A. 120 equal month installments of $287,238.67 to be paid in advance on
or before the first day of each month during the period beginning on the
Commencement Date and ending on the day before the tenth (10th) Anniversary; and

        B. 120 equal monthly installments of $27,323.00 to be paid in advance on
or before the first day of each month during the period beginning on the tenth
(10th) Anniversary and ending on the Termination Date.
<PAGE>

             IV.  RENTABLE AREA OF BUILDING.

        Section 2(a) (vii) is amended by striking out "1.030,981" in line one
(1) and inserting in lieu thereof "1,031,323".

             V.   RENTABLE AREA OF DEMISED PREMISES.

        Section 2(a) (viii) is amended by striking out "160,208" in line one (1)
and inserting in lieu thereof "160,784".

             VI.  TENANT'S PROPORTION.

        Section 2(a) (xi) is amended by striking "15.54" and inserting in lieu
thereof "15.59".

             VII. TAXES/EXPENSES.

        Section 2(d) is amended by striking "$5,670,396.00" in line two (2) and
inserting in lieu thereof "$5,672,276.50".

             VIII.DEMISING PLANS.

A.      "New Exhibit A-1" is deleted and replaced by "Current Exhibit A-1"
attached hereto;

B.      "New Exhibit A-3" is deleted and replaced by "Current Exhibit A-3"
attached hereto;

C.      "New Exhibit A-5" is deleted and replaced by "Current Exhibit A-5"
attached hereto;

D.      "Exhibit "A-7a" " and "Exhibit "A-7b"" are deleted and replaced by "New
Exhibit A-7" attached hereto; and

E.      "Exhibit "A-8"" is deleted and replaced by "New Exhibit A-8" attached
hereto.

             IX.  RENT CREDIT.

A.      Section 31.A. of the Lease is amended by striking out column "B" and
inserting in lieu thereof:

             "    $    203,472.00
                       203,472.00
                       203,472.00
                  ---------------
                  $    601,416.00   "

B.      Section I.A. of the Third Amendment to Lease is amended by deleting
"$48,062.40 (160,208 X $0.30)" and inserting in lieu thereof "$48,235.20
(160,784 X $0.30)".

                                       2
<PAGE>

             X.   TERMS OF LEASE.

        IN WITNESS WHEREOF, the parties hereto have executed this Fourth
Amendment to Lease as of the date first above written.

                                  This instrument is executed by AMERICAN
                                  NATIONAL BANK AND TRUST COMPANY OF CHICAGO,
                                  not personally but solely as Trustee, as
                                  aforesaid. All the covenants and conditions to
                                  be performed hereunder by AMERICAN NATIONAL
                                  BANK AND TRUST COMPANY OF CHICAGO are
                                  undertaken by it solely as Trustee, as
                                  aforesaid and not individually, and no
                                  personal liability shall be asserted or be
                                  enforceable against AMERICAN NATIONAL BANK AND
                                  TRUST COMPANY OF CHICAGO by reason of any of
                                  the covenants, statements, representations or
                                  warranties contained in this instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:                           By /s/
                                    --------------------------------
                                  Its          Vice President

By /s/
  ------------------------------
Its     Assistant Secretary

                                                TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST:                           By /s/
                                    --------------------------------
                                  Its     Senior Vice President

By /s/
  ------------------------------
Its     Assistant Secretary
<PAGE>

                            FIFTH AMENDMENT TO LEASE
                            ------------------------

        This Fifth Amendment to Lease is made and entered into as of this 7th
day of October, 1982, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not individually but solely as Trustee under the provisions of a
certain Trust Agreement dated March 20, 1980, and known as Trust No. 48268
("Landlord") and CHICAGO MERCANTILE EXCHANGE, an Illinois not-for-profit
corporation ("Tenant").

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a certain Agreement of Lease
dated May 11, 1981 pursuant to which Landlord leased to Tenant, and Tenant
leased from Landlord 100,000 square feet of office space on the Lobby Level and
2nd - 6th Floors of the Building located at 30 South Wacker Drive, Chicago,
Illinois (hereinafter called the "Building"); and a First Amendment to Lease
dated February 1, 1982; a Second Amendment to Lease dated April 26, 1982; a
Third Amendment to Lease dated June 29, 1982; a Fourth Amendment to Lease dated
July 28, 1982; and

        WHEREAS, Landlord and Tenant desire to enter into this Fifth Amendment
to Lease for the purposes of amending the Lease is hereinafter set forth;

        NOW THEREFORE, for a good and valuable consideration, the receipt and
sufficiency whereof being hereby acknowledged, Landlord and Tenant hereby agree
as follows:

             I.   ELEVATOR.

        Section 49 of the Lease is amended:

             1.   by striking out "#2" in line 4 and inserting in lieu thereof
                  "#1";

             2.   by the addition of the following:

                  "The Elevator shall serve (among other floors) the 9th and
                  10th Floors of the Building except that on notice to Landlord,
                  Tenant may elect to delete service to the 9th and 10th Floors
                  of the Building."

             II.  TERMS OF LEASE.

        Except as hereinbefore modified or amended, the provisions, conditions
and terms of the Lease shall remain unchanged and in full force and effect.

                                       1
<PAGE>

        IN WITNESS WHEREOF, the parties hereto have executed this Fifth
Amendment to Lease as of the date first above written.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

                                  By  /s/
                                    -----------------------------------
                                  ITS          Vice President
ATTEST:

By /s/
  -------------------------------
ITS      Assistant Secretary

                                 This instrument is executed by AMERICAN
                                 NATIONAL BANK AND TRUST COMPANY OF CHICAGO, not
                                 personally but solely as Trustee, as aforesaid.
                                 All the covenants and conditions to be
                                 performed hereunder by AMERICAN NATIONAL BANK
                                 AND TRUST COMPANY OF CHICAGO are undertaken by
                                 it solely as Trustee, as aforesaid and not
                                 individually, and no personal liability shall
                                 be asserted or be enforceable against AMERICAN
                                 NATIONAL BANK AND TRUST COMPANY OF CHICAGO by
                                 reason of any of the covenants, statements,
                                 representations or warranties contained in this
                                 instrument.

                                                    TENANT

                                 CHICAGO MERCANTILE EXCHANGE, an Illinois
                                 not-for-profit corporation

                                  By /s/
                                    -----------------------------------
                                  ITS     Senior Vice President

ATTEST:

By /s/
  -------------------------------
ITS       Secretary

                                       2
<PAGE>

                                 SIXTH AMENDMENT
                                 ---------------
        THIS Sixth AMENDMENT is made as of this 5th day of July 1983, between

        AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking
association of Chicago, Illinois not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980, and known as
Trust No. 48268 ("Landlord"), and

        CHICAGO MERCANTILE EXCHANGE, an Illinois
        not-for-profit corporation ("Tenant")

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a Lease dated May 11, 1981
pursuant to which Tenant leased 160,784 square feet on the Upper Lobby Level and
the 2nd-8th floors of the building located at 30 South Wacker Drive, Chicago,
Illinois ("Building"); and a First Amendment to Lease dated February 1, 1982; a
Second Amendment to Lease dated April 26, 1982; a Third Amendment to Lease dated
June 29, 1982; a Fourth Amendment to Lease dated July 28, 1982; and a Fifth
Amendment to Lease dated October 7, 1982 (hereinafter collectively referred to
as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Sixth Amendment
for the purpose of amending the Lease;

        NOW, THEREFORE, for a good and valuable consideration, the receipt and
sufficiency being hereby acknowledged, Landlord and Tenant agree as follows:

             I.   MEMBER SPACE.

             Sections 25.D.3.a. (I) and (ii) are deleted in their entirety and
replaced with the following:

        "    (i)  in the Members' Space, or

             (ii) in the succeeding floors of the Building immediately above the
             Members' Space, or

             (iii) at the discretion of Landlord, in the lower part of the Phase
             II Tower.

             (iv) Notwithstanding subsections a.(I) and (ii) to the contrary,
             Landlord, at its discretion, may exclude the 22nd floor of the
             Building from the space described in subsections a. (i) and (ii)
             above. Such exclusion shall not, however, diminish the amount of
             Member, Five, Ten, and Fifteen Year Space and replacement
             Premises."
<PAGE>

             II.  EXPANSION OPTIONS.

             Section 26.E. is deleted in its entirety and replaced with the
following:

        "    E.   The Five, Ten and Fifteen Year Space may, at the discretion of
             Landlord, be located either;

                  1. on floors above the demised premises within space leased
                  by Members (sites to be selected by Tenant), or

                  2. in the Phase II Tower.

                  3. If the Phase II Tower be selected, Landlord shall make
                  reasonable efforts to designate the lower floors
                  (sequentially).

                  4. Notwithstanding subsection E. (1) above, to the contrary,
                  Landlord, and its discretion, may exclude the 22nd floor of
                  the Building from the space described in subsection E.1 above.
                  Such exclusion shall not, however, diminish the amount of
                  Five, Ten and Fifteen Year Space."

             III. TERMS OF LEASE.

             Except as herein modified or amended, the provisions, conditions
and terms of the Lease shall remain unchanged and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Sixth Amendment as of
the date first above written.

This instrument is executed by AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee, as aforesaid. All the covenants
and conditions to be performed hereunder by AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO are undertaken by it solely as Trustee, as aforesaid and not
individually, and no personal liability shall be asserted or be enforceable
against AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO by reason of any of
the covenants, statements, representations or warranties contained in this
instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:

By /s/                              By /s/
  ------------------------------      -------------------------------
Title    ASSISTANT SECRETARY           Title     VICE PRESIDENT
     ---------------------------            -------------------------

                                                           TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST OR WITNESS:

By /s/                              By /s/
  ------------------------------      -------------------------------
Title        ASSISTANT                Title   SENIOR VICE PRESIDENT
     ---------------------------            -------------------------

                                       2
<PAGE>

                                SEVENTH AMENDMENT
                                -----------------

        THIS Seventh AMENDMENT is made as of this 19th day of September 1983,
between AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking
association of Chicago, Illinois not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980, and known as
Trust No. 48268 ("Landlord"), and

        CHICAGO MERCANTILE EXCHANGE,
        an Illinois not-for-profit corporation
("Tenant")

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a Lease dated May 11, 1981
pursuant to which Tenant leased 160,784 square feet on the Upper Lobby Level and
the 2nd-8th floors of the building located at 30 South Wacker Drive, Chicago,
Illinois ("Building"); and a First Amendment to Lease dated February 1, 1982; a
Second Amendment to Lease dated April 26, 1982; a Third Amendment to Lease dated
June 29, 1982; a Fourth Amendment to Lease dated July 28, 1982; a Fifth
Amendment to Lease dated October 7, 1982; and a Sixth Amendment to Lease dated
July 5, 1983 (hereinafter collectively referred to as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Seventh Amendment
for the purpose of amending the Lease;

        NOW, THEREFORE, for a good and valuable consideration, the receipt and
sufficiency being hereby acknowledged, Landlord and Tenant agree as follows:

             I.   DESIGN CALCULATIONS CORRECTIONS.

A. The exhibits marked "Current Exhibit A-1", "New Exhibit A-2", "Current
Exhibit A-3", "New Exhibit "A-4", "Current Exhibit "A-5", "New Exhibit A-6",
"New Exhibit A-7" and "New Exhibit A-8" are hereby stricken in their entirety
and replaced by the exhibits marked "Exhibit AA-1 (dated November 10, 1983),
AA-2, AA-3, AA-4, AA-5, AA-6, AA-7 and AA-8" dated July 20, 1983 and attached
hereto.

B. The Title Page of the Lease is amended by deleting "160,784 Square Feet on
the Upper Lobby Level and 2nd-8th Floors" and inserting in lieu thereof "161,160
Square Feet on the Upper Lobby Level and 2nd-8th Floors".

                                       1
<PAGE>

C. The Witnesseth Section of the Lease is amended by deleting in line 3 "160,784
Square Feet on the Upper Lobby Level and 2nd-8th Floors" and inserting in lieu
thereof "161,160 Square Feet on the Upper Lobby Level and 2nd-8th Floors".

D. The total Base Rent of $67,027,400.40 payable as set forth in Section 1 of
the Lease is amended to be a total Base Rent of $67,179,680.40 as set forth in
said Section 1 of the Lease except that it shall be payable as follows:

        1. 120 equal monthly installments of $287,873.17 to be paid in advance
        on or before the first day of each month during the period beginning on
        the Commencement Date and ending on the day before the tenth (10th)
        Anniversary; and

        2. 120 equal monthly installments of $271,957.50 to be paid in advance
        on or before the first day of each month during the period beginning on
        the tenth (10th) Anniversary and ending on the Termination Date.

E. Section 2(a)(vii) is amended by striking "1,031,323" in line one (1) and
inserting in lieu thereof "1,033,628".

F. Section 2(a)(viii) is amended by striking "160,784" in line one (1) and
inserting in lieu thereof "161,160".

G. INTENTIONALLY OMITTED.

H. Section 2(d) is amended by striking $5,672,276.50" in line two (2) and
inserting in lieu thereof $5,684,954.00".

I. Section 31.A. of the Lease is amended by striking out column "B" and
inserting in lieu thereof:

        "    $    204,106.50
                  204,106.50
                  204,106.50
             ---------------
             $    612,319.50 "

J. Section 38 of the Lease is amended by:

1.      striking out "13,643" in line 3 of Section 38.A. and inserting in lieu
thereof "13,702"; and

2.      striking and deleting "Exhibit A-1a" and replacing it with "Exhibit
AA-1a" attached hereto; and

3.      striking out "$253,214.00" in line 2 of Section 38.A.2. and inserting in
lieu thereof "$254.309.12"; and

4.      striking out "$505,337.00" in line 2 of Section 38.A.3. and inserting in
lieu thereof "$507,522.08"; and

                                       2
<PAGE>

5.      deleting and striking out the first sentence of Section 38.B.1. in its
entirety and inserting in lieu thereof the following:

        "1. A lease on the Members Lease Form for a twenty (20) year term (with
        no Work Letter and no Attachment "A") shall be prepared to reflect total
        Base Rent of SIX MILLION EIGHT HUNDRED FIFTY THOUSAND NINE HUNDRED
        NINETY-NINE AND 20/100 DOLLARS ($6,850,999.20) payable in two hundred
        forty (240) monthly installments of TWENTY EIGHT THOUSAND FIVE HUNDRED
        FORTY-FIVE AND 83/100 DOLLARS (428.545.83)".

6.      by striking out "$505,337.00" in line 2 of Section 38.B.4. and inserting
in lieu thereof "$507.522.08"; and

7.      striking out Sections 38.B.5.(a), 38.B.5.(b) and 38.B.5.(c) in their
entirety; and

8.      deleting "and the Advance under Section 38.(B) (5)", in lines 3 and 4 in
Section 38.D. and inserting in line three (3) before "the Credit" the work
"and"; and

9.      deleting "28.57%" in Section 38.D.1. and inserting in lieu thereof
"50%"; and

10.     deleting "28.57% in Section 38.D.2. and inserting in lieu thereof "50%";
and

11.     deleting Section 38.D.3. in its entirety.

12.     Section I.A. of the Third Amendment to Lease is amended by deleting
"$48,235.20 (160,784 X $0.30)" and inserting in lieu thereof "$48,348.00
(161,160 X $0.30)".

             II. THIRD ADDITIONAL SPACE

A. The demised premises are increased from 161,160 Square Feet on the Upper
Lobby Level and 2nd-8th Floors *inclusive) to 171,601 Square Feet on the Upper
Lobby Level and 2nd through 8th Floors (inclusive) and the 10th floor by the
addition of 10,441 square feet on the 10th floor as shown on Exhibit "A-10"
dated October 20, 1983, attached hereto ("Third Additional Space").

B. The Title Page of the Lease is amended by deleting "161,160 Square Feet on
the Upper Lobby Level and 2nd-8th Floors" and inserting in lieu thereof "171,601
Square Feet on the Upper Lobby Level, the 2nd through 8th floors (inclusive) and
the 10th Floor".

C. The Witnesseth Section of the Lease is amended by deleting in line 3 "161,160
Square Feet on the Upper Lobby Level and 2nd-8th Floors" and inserting in lieu
thereof "171,601 Square Feet on the Upper Lobby Level, the 2nd through 8th
floors (inclusive) and the 10th Floor".

D. The total Base Rent of $67,179,680.40 payable as set forth in Section 1 of
the Lease is amended to be a total Base Rent of $71,408,286.00 as set forth in
said Section 1 of the Lease except that it shall be payable as follows:

                                       3
<PAGE>

        1. 120 equal month installments of $305,492.36 to be paid in advance on
        or before the first day of each month during the period beginning on the
        Commencement Date and ending on the day before the tenth (10th)
        Anniversary; and

        2. 120 equal monthly installments of $289,576.69 to be paid in advance
        on or before the first day of each month during the period beginning on
        the tenth (10th) Anniversary and ending on the Termination Date.

E.      Section 2(a)(viii) is amended by striking "161,160" in line one (1) and
inserting in lieu thereof "171,601".

F.      Section 2(a)(xi) is amended by striking "15.59" in line one (1) and
inserting in lieu thereof "16.60".

G.      Section 31.A. of the Lease is amended by striking out column "B" and
inserting in lieu thereof:

        "    $    221,725.69
                  221,725.69
                  221,725.69
             ---------------
             $    665,177.07 "

H.      Section I.A. of the Third Amendment to Lease is amended by deleting
"$48,348.00 (161,160 X $0.30)" and inserting in lieu thereof "$51,480.30
(171,601 X $0.30)".

I.      The Commencement Date and commencement of Base Rent and/or Rent
Adjustments for the initial demised premises (161,160 square feet on the Upper
Lobby and 2nd-8th floors) plus any space to be added to such initial demised
premises at the Commencement Date pursuant to Section 25.B.2.a. ("Gap Space"),
shall not be delayed if the Third Additional Space and/or the Gap Space is not
Ready for Occupancy contemporaneously with such initial demised premises.

             III. RIGHT OF FIRST OFFERING.

             Section 30.A.2. of the Lease is deleted in its entirety and
replaced with the following:

        "    2.   Landlord's receipt of the Interest Notice for any portion of
             the Offering Space (except B.7. below) during the period commencing
             two (2) years prior to the expiration date of each Offering Lease
             (defined below) and ending 460 days thereafter.  For the space on
             the ten (10) lowest office floors of the Phase II Tower, Tenant
             need not give an Interest Notice for the initial leasing of such
             space.  Landlord shall give an Advice when it commences marketing
             such space. Subsequent to the initial leasing of the ten (10)
             lowest office floors of the Phase II Tower, an Interest Notice
             shall be required of Tenant as stated in this Section 30; and "

             IV.  CLEANING CREDIT.

             Tenant shall have the right, at Tenant's expense, to contract
separately for all cleaning services to be provided by Landlord (or Landlord's
contractor(s)) pursuant to Section 3(a)(iv) of the Lease so long as such
separate contract and

                                       4
<PAGE>

the services to be rendered pursuant thereto do not create any jurisdictional or
other labor disputes for Landlord. Tenant shall notify Landlord of its intention
to contract separately for cleaning services pursuant to the provisions of this
Section, and Landlord shall remit to Tenant, monthly, as and for Landlord's
payment for such cleaning services separately contracted for, an amount equal to
actual costs saved by Landlord by reason of Landlord's discontinuance of
cleaning services for the demised premises. Tenant's said notice to Landlord
shall not be less than three (3) months in advance of the date of commencement
of such separate cleaning services. All such separate cleaning services shall be
performed in accordance with Landlord's reasonable rules and regulations. It is
understood and agreed that should Tenant contract separately for its cleaning
services as aforesaid with a contractor other than Landlord's cleaning
contractor, Landlord need not provide storage or other facilities for such other
contractor and, Landlord shall not act in bad faith to defeat or diminish the
amount to be remitted to Tenant by reason of said actual costs saved by
Landlord, by unwarrantedly increasing cleaning services to other tenants in the
Building, or otherwise.

             V.   TERMS OF LEASE.

             Except as herein modified or amended, the provisions, conditions
and terms of the Lease shall remain unchanged and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Seventh Amendment as
of the date first above written.

This instrument is executed by AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee, as aforesaid. All the covenants
and conditions to be performed hereunder by AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO are undertaken by it solely as Trustee, as aforesaid and not
individually, and no personal liability shall be asserted or be enforceable
against AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO by reason of any of
the covenants, statements, representations or warranties contained in this
instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:

By /s/                              By /s/
  ------------------------------      -------------------------------
Title    ASSISTANT SECRETARY           Title     VICE PRESIDENT
     ---------------------------            -------------------------

                                                  TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST

By /s/                              By /s/
  ------------------------------      -------------------------------
Title        CONTROLLER               Title   SENIOR VICE PRESIDENT
     ---------------------------            -------------------------

                                       5
<PAGE>

                                EIGHTH AMENDMENT
                                ----------------

        THIS Eighth AMENDMENT is made as of this 17th day of October 1983,
between AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking
association of Chicago, Illinois not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980, and known as
Trust No. 48268 ("Landlord"), and
        CHICAGO MERCANTILE EXCHANGE,
        an Illinois not-for-profit corporation
("Tenant")

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a Lease dated May 11, 1981
pursuant to which Tenant leased 171,601 square feet on the Upper Lobby Level and
the 2nd through 8th floors (inclusive) and the 10th floor of the building
located at 30 South Wacker Drive, Chicago, Illinois ("Building"); and a First
Amendment to Lease dated February 1, 1982; a Second Amendment to Lease dated
April 26, 1982; a Third Amendment to Lease dated June 29, 1982; a Fourth
Amendment to Lease dated July 28, 1982; a Fifth Amendment to Lease dated October
7, 1982; a Sixth Amendment to Lease dated July 5, 1983; and a Seventh Amendment
to Lease dated September 19, 1983 (hereinafter collectively referred to as
"Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Eighth Amendment
for the purpose of amending the Lease;

        NOW, THEREFORE, for a good and valuable consideration, the receipt and
sufficiency being hereby acknowledged, Landlord and Tenant agree as follows:

             I.   ALTERATIONS AND CONSTRUCTION.

             Section 8(j) of the Lease is amended by striking out the margin
addition and inserting in lieu thereof the following:

"provided however, that if Tenant has on deposit with Landlord one hundred fifty
percent (150%) of the lien in cash or title insurance over such lien claim and
otherwise holds Landlord harmless and indemnifies Landlord, Tenant may contest
the lien. Landlord shall be entitled to hold such funds until the lien is
discharged of record (or paid if a notice is served), provided that Tenant may
direct payment of said lien claim by Landlord from such funds if Landlord has
received appropriate discharge or release documents."

                                       1
<PAGE>

             II.  UNTENANTABILITY.

             Section 10 of the Lease is amended by striking out the margin
addition on the lower left corner of page 9 and inserting in lieu thereof the
following:

" and if the Trading Floor has not been made untenantable or if it has been made
untenantable and the owner of the Trading Floor contracts for or commences the
Trading Floor's construction, or repair, then this Lease shall not terminate.
Landlord, at its expense, shall proceed with all due diligence to repair,
restore or rehabilitate all damaged portions of the exterior of the Building,
the demised premises, all other areas of the Building serving the demised
premises or providing ingress to or egress therefrom (including without
limitation the parking garage, Building lobbies and all areas occupied by
equipment or other facilities serving the demised premise or the Trading Floor).
In addition, in the event Landlord elects not to rebuild all or any portion of
Five, Ten or Fifteen Year Space not then part of the demised premises, a
proportionate allocation of insurance proceeds received by Landlord shall be
immediately deposited in escrow with a title company or bank for the sole
purpose of being used to repair, restore or rehabilitate such Five, Ten, and
Fifteen Year Space when and as Tenant exercises its option to lease such Space.
If, however, the demised premises or the Building and the Trading Floor are made
untenantable by fire or other casualty and if the owner of the Trading Floor
does not so construct or commence such reconstruction of the Trading Floor,"

             III. ASSIGNMENT AND SUBLETTING.

             Section 13 of the Lease is hereby deleted and stricken in its
entirety and replaced with the following:

             13.  ASSIGNMENT-SUBLETTING.

A. Assignment. Tenant shall not assign, hypothecate, mortgage, encumber, convey
this Lease or otherwise permit the use or occupancy of the demised premises or
any part thereof by anyone other than Tenant without the prior written consent
of Landlord. Landlord shall not unreasonably withhold its consent to an
assignment except that Landlord need not consent to an assignment of this Lease,
if:

        1.   in the reasonable judgment of Landlord the assignee is of a
character or engaged in a business which is not in keeping with the standards of
Landlord for the Building;

        2. in the reasonable judgment of Landlord the purpose for which the
assignee intends to use the demised premises are not in keeping with the
standards of Landlord for the Building, or are in violation of the terms of any
other leases in the Building, it being understood that the purpose for which
assignee intends to use the demised premises may not be in violation of this
Lease;

                                       2
<PAGE>

        3. the assignee is either a government (or subdivision or agency
thereof) or an occupant of the Building;

        4. less than the remaining term of the Lease is being assigned;

        5. the assignee is not, in the reasonable judgment of Landlord, solvent
or does not have unencumbered assets of a value at least equal to twice the
projected costs of the obligations to be assumed for the unexpired term of the
Lease;

        6. Tenant is in default under this Lease.

The withholding of consent by Landlord to any assignment shall not affect or
diminish any right of Tenant to sublet all or any part of the Premises to any
person or entity subject to the provisions of Section 13.B.

B. Subletting. Tenant shall have the right, without Landlord's consent, to
sublet all or any portion of the demised premises; except that during the first
twenty (20) years of the Lease term, Landlord's consent shall be required with
respect to:

        1.   Subletting of Five Year Space to either:

             a.   Members who are not then tenants of the Building; or

             b.   Members who have leased space in the Building under a lease
             with a five year term;

        2. Subject to subsection B.3. below, subletting more than 26,000 square
feet in the aggregate to Members during the second ten (10) years of the term of
the Lease; or

        3. Subletting if the commencement date of the proposed sublease will
occur during the six month period after Tenant has exercised an option to lease
Five, Ten or Fifteen Year Space pursuant to Section 26 unless such Five, Ten or
Fifteen Year Space is contiguous to a pre-existing portion of the demised
premises.

C. If Tenant sublets the demised premises or any part thereof:

        1. the terms and conditions of this Lease, including among other things,
the use provisions, shall in no way be deemed modified, abrogated or amended.

        2. Tenant shall pay Landlord as additional Base Rent, sixty percent
(60%) of any excess rent (together with escalation) payable to and collected by
Tenant under the sublease over the Base Rent plus Rent Adjustments payable to
Landlord under this Lease, except that notwithstanding any other provision of
this Lease, there shall be no abatement or reduction of Base Rent or Rent
Adjustments as a result of amounts payable pursuant to clause 2. Of this Section
13.C. Such excess rent shall first be reduced by sixty percent (60%) of the
following:

                                       3
<PAGE>

             a. subletting commissions;

             b. advertising or legal expenses involved in the subletting or in
             subsequently enforcing the terms thereof; and

             c. Tenant's actual expenditures for improvements it is required to
             make as a result of the sublease except that such improvement
             expense for purposes of this reduction may not exceed sixty percent
             (60%) of ten percent (10%) of any project excess rent together with
             escalation.

        3. Landlord shall be provided a copy of the subletting documents within
ten (10) days after their complete execution;

        4. the subletting documents must contain default provisions similar to
those contained in this Lease in the event of a default under the sublease
Tenant agrees to use reasonable efforts to promptly enforce such provisions.

D. In the event of any assignment or subletting the liability of Tenant for the
demised premises shall in no way be deemed modified, abrogated or amended. "

             IV.  MISCELLANEOUS.

             Section 24(l) of the Lease is deleted and stricken in its entirety
and replaced with the following:

" (1) Landlord and Tenant agree (upon thirty (30) days or more advance notice)
each will deliver to the other a written statement certifying:

             (1) that this Lease is unmodified and in full force and effort (or
if there have been modifications that the same is in full force and effect as
modified and identifying the modifications),

             (2) the dates to which Base Rent, Rent Adjustments, Rent Adjustment
Deposits and other charges have been paid,

             (3) that so far as the person making the certificate knows, the
other is not in default under the Lease, if such be the case, and

             (4)  such other information as shall be reasonably required by
either Landlord or Tenant.   "

             V.   RETAIL SPACE.

             Section 36 of the Lease is hereby deleted and stricken

                                       4
<PAGE>

in its entirety.

             VI.  PRIVATE RESTAURANT CLUB SPACE.

             Section 38 of the Lease is hereby deleted and stricken in its
entirety.

VII.    TERMS OF LEASE.

        Except as herein modified or amended, the provisions, conditions and
terms of the Lease shall remain unchanged and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Eighth Amendment as of
the date first above written.

This instrument is executed by AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee, as aforesaid. All the covenants
and conditions to be performed hereunder by AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO are undertaken by it solely as Trustee, as aforesaid and not
individually, and no personal liability shall be asserted or be enforceable
against AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO by reason of any of
the covenants, statements, representations or warranties contained in this
instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:

By /s/                            By /s/
  --------------------------        ---------------------------
  Title  ASSISTANT SECRETARY        Title     VICE PRESIDENT
       ---------------------             ----------------------

                                                 TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST:

By /s/                            By /s/
  --------------------------        ---------------------------
  Title  CONTROLLER                 Title SENIOR VICE PRESIDENT
       ---------------------             ----------------------

                                       5
<PAGE>

                                 NINTH AMENDMENT
                                 ---------------

        THIS Ninth AMENDMENT is made as of this 3rd day of December 1984,
between AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking
association of Chicago, Illinois not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980, and known as
Trust No. 48268 ("Landlord"), and

                          CHICAGO MERCANTILE EXCHANGE,
                     an Illinois not-for-profit corporation
("Tenant")

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a Lease dated May 11, 1981
pursuant to which Tenant leased 171,601 square feet on the Upper Lobby Level,
2nd through 8th and 10th Floors of the building located at 30 South Wacker
Drive, Chicago, Illinois ("Building"); and a First Amendment to Lease dated
February 1, 1982; a Second Amendment to Lease dated April 26, 1982; a Third
Amendment to Lease dated June 29, 1982; a Fourth Amendment to Lease dated July
28, 1982; a Fifth Amendment to Lease dated October 7, 1982; a Sixth Amendment to
Lease dated July 5, 1983; a Seventh Amendment to Lease dated September 19, 1983;
and an Eighth Amendment to Lease dated October 17, 1983 (hereinafter
collectively referred to as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Ninth Amendment
for the purpose of amending the Lease;

        NOW, THEREFORE, for a good and valuable consideration, the receipt and
sufficiency being hereby acknowledged, Landlord and Tenant agree as follows:

             I.      SECOND SPACE.

             Effective December 1, 1983, the Second Space (Section I.I. of the
Second Amendment) of 40,208 square feet is amended to 29,117 square feet, the
reduction being calculated as follows:

First Reservation Space (Section 25.A.1)              400,000 square feet

        less First Reservation
        Space leased by Tenant                       (131,393) square feet*

        less First Reservation
        Space leased by Members                      (253,265) square feet

        less Gap Space                                 (4,251) square feet

Reduction                                              11,091 square feet

* Effective December 1, 1983, the First Reservation Space leased by Tenant is
142,484 square feet.

                                       1
<PAGE>

             II.  BASE RENT.

             The total Base Rent of $71,408,286.00 payable as set forth in
Section 1 of the Lease is amended to be a total Base Rent of $70,881,463.20 as
set forth in said Section 1 of the Lease except monthly installments of Base
Rent shall be payable as follows:

A. One hundred twenty (120) equal monthly installments of $301,102.17 to be paid
in advance on or before the first day of each month during the period beginning
December 1, 1983 (Commencement Date) and ending November 30, 1993; and

B. One hundred twenty (120) equal monthly installments of $289,576.69 to be paid
in advance on or before the first day of each month during the period beginning
December 1, 1993 and ending November 30, 2003 (Termination Date).

             III. TENANT CREDIT.

A. Landlord, if Tenant is not in default under the Lease, hereby grants Tenant a
credit of $56,148.18 to be applied against monthly installments of Base Rent as
follows:

                 Month                        Amount
                 -----                        ------
             January, 1984                  $18,716.06
             February, 1984                  18,716.06
             March, 1984                     18,716.06
                                            ----------
                             Total          $56,148.18

B. The balance of Base Rent and/or Rent Adjustments due for any month to which a
credit has been applied shall be paid as provided in Sections 1 and 2 of the
Lease.

                                       2
<PAGE>

             IV.  TERMS OF LEASE.

        Except as herein modified or amended, the provisions, conditions and
terms of the Lease shall remain unchanged and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Ninth Amendment as of
the date first above written.

This instrument is executed by AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee, as aforesaid. All the covenants
and conditions to be performed hereunder by AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO are undertaken by it solely as Trustee, as aforesaid and not
individually, and no personal liability shall be asserted or be enforceable
against AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO by reason of any of
the covenants, statements, representations or warranties contained in this
instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:

By /s/                            By /s/
  ----------------------------      ---------------------------
  Title  SECOND VICE PRESIDENT    Title     VICE PRESIDENT
       -----------------------           ----------------------

                                                 TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST:

By /s/                            By /s/
  --------------------------        ---------------------------
  Title  HOME COUNSEL               Title SENIOR VICE PRESIDENT
       ---------------------             ----------------------
<PAGE>

                                 TENTH AMENDMENT
                                 ---------------

        THIS Tenth AMENDMENT is made as of this 16th day of March 1987, between
AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO, a national banking
association of Chicago, Illinois not individually but solely as Trustee under
the provisions of a certain Trust Agreement dated March 20, 1980, and known as
Trust No. 48268 ("Landlord"), and

                          CHICAGO MERCANTILE EXCHANGE,
                     an Illinois not-for-profit corporation
("Tenant")

                                   WITNESSETH:

        WHEREAS, Landlord and Tenant entered into a Lease dated May 11, 1981
pursuant to which Tenant leased 171,601 square feet on the Upper Lobby Level,
2nd through 8th and 10th Floors of the building located at 30 South Wacker
Drive, Chicago, Illinois ("Building"); a First Amendment to Lease dated February
1, 1982; a Second Amendment to Lease dated April 26, 1982; a Third Amendment to
Lease dated June 29, 1982; a Fourth Amendment to Lease dated July 28, 1982; a
Fifth Amendment to Lease dated October 7, 1982; a Sixth Amendment to Lease dated
July 5, 1983; a Seventh Amendment to Lease dated September 19, 1983; an Eighth
Amendment to Lease dated October 17, 1983, and a Ninth Amendment dated December
3, 1984 (hereinafter collectively referred to as "Lease"); and

        WHEREAS, Landlord and Tenant desire to enter into this Tenth Amendment
for the purpose of amending the Lease;

             I.   Adjustment of First Reservation Space and Second Space.

A. Effective December 1, 1983, the Second Space of 29,117 square feet as
adjusted pursuant to Section I of the Ninth Amendment is decreased to 28,595
square feet, and the First Reservation Space leased by Tenant of 142,484 square
feet as adjusted pursuant to Section I of the Ninth Amendment is increased to
143,006 square feet.

B. 1. By reason of said adjustment, Landlord, if Tenant is not in default under
the Lease, shall grant Tenant a credit of $2,642.64 to be applied against Base
Rent as it becomes due under the Lease. $2,642.64 is calculated as follows:

                       (522 X $20.25)
                       --------------  X   3   =  $2,642.64
                             12

        2. The balance of Base Rent and/or Rent Adjustments due for any month in
which a credit has been applied shall be paid as provided in Sections 1 and 2 of
the Lease.

                                       1
<PAGE>

             II.  Fourth Additional Space.

        Retroactively effective June 1, 1984:

A. The demised premises are increased from 171,601 square feet on the Upper
Lobby Level, 2nd-8th and 10th floors of the Building to 175,330 square feet on
the Upper Lobby Level, 2nd-8th, 10th, 14th, 15th and 17th floors of the Building
by addition of the 1,404 square feet on the 14th floor shown on Exhibit "A-1",
the 699 square feet and 350 square feet on the 15th floor shown on Exhibits
"A-2" and "A-3" respectively and the 928 square feet and 348 square feet on the
17th floor shown on Exhibits "A-4" and "A-5" respectively (such 3,729 square
feet is hereinafter collectively referred to as "Fourth Additional Space").

B. The Title Page of the Lease is amended by deleted 171,601 Square Feet on the
Upper Lobby Level, the 2nd through 8th floors (inclusive) and the 10th Floors
and inserting in lieu thereof 175,330 Square Feet on the Upper Lobby Level, the
2nd through 8th Floors (inclusive) and the 10th, 14th, 15th and 17th Floors; and

C. The Witnesseth Section of the Lease is amended by deleting in line 3 171,601
Square Feet on the Upper Lobby Level, the 2nd through 8th floors (inclusive) and
the 10th Floor and inserting in lieu thereof 175,330 Square Feet on the Upper
Lobby Level, the 2nd through 8th Floors (inclusive) and the 10th, 14th, 15th,
and 17th Floors; and

D. The term for the Fourth Additional Space shall commence and thereupon be
considered demised premises subject to all terms and conditions of the Lease;
and

E. Section 2(a)(viii) of the Lease is amended by striking 171,601 in line 1 and
inserting in lieu thereof 175,330; and

F. Section 2(a)(xi) is amended by striking 16.60 in line 1 and inserting in lieu
thereof 16.96; and

G. All references to Gap Space under the Lease shall be deemed to refer to
Fourth Additional Space.

             III. First Deletion Space.

             Retroactively effective March 31, 1986:

A. The demised premises are decreased from 175,330 square feet on the Upper
Lobby Level, 2nd-8th, 10th, 14th, 15th and 17th floors of the Building to
174,982 square feet on the Upper Lobby Level, 2nd-8th, 10th, 14th, 15th and 17th
floors of the Building by deletion of the 348 square feet on the 17th floor
shown on attached Exhibit "B" ("First Deletion Space").

B. The Title Page of the Lease is amended by deleting 175,330 Square Feet on the
Upper Lobby Level, the 2nd through 8th Floors (inclusive) and the 10th, 14th,
15th and 17th Floors and inserting in lieu thereof 174,982 Square Feet on the
Upper Lobby Level, the 2nd through 8th Floors (inclusive) and the 10th, 14th,
15th and 17th Floors; and

                                       2
<PAGE>

C. The Witnesseth Section of the Lease is amended by deleting in line 3 175,330
Square Feet on the Upper Lobby Level, the 2nd through 8th Floors (inclusive) and
the 10th, 14th, 15th and 17th Floors and inserting in lieu thereof 174,982
Square Feet on the Upper Lobby Level, the 2nd through 8th Floors (inclusive) and
the 10th, 14th, 15th and 17th Floors; and

D. Section 2(a) (viii) of the Lease is amended by striking 175,330 in line 1 and
inserting in lieu thereof 174,982; and

E. Section 2(a) (xi) is amended by striking 16.96 in line 1 and inserting in
lieu thereof 16.93.

             IV.  Fifth Additional Space.

             Effective April 1, 1987:

A. The demised premises are increased from 174,982 square feet on the Upper
Lobby Level, 2nd-8th, 10th, 14th, 15th and 17th floors of the Building to
176,363 square feet on the Upper Lobby Level, 2nd-8th, 10th, 14th, 15th and 17th
floors of the Building by addition of the 1,381 square feet on 10th floor shown
on attached Exhibit "C" ("Fifth Additional Space").

B. The Title Page of the Lease is amended by deleting 174,982 Square Feet on the
Upper Lobby Level, 2nd through 8th Floors (inclusive), and the 10th, 14th, 15th
and 17th floors and inserting in lieu thereof 176,363 square feet on the Upper
Lobby Level, 2nd through 8th Floors (inclusive), and the 10th, 14th, 15th and
17th Floors; and

C. The Witnesseth Section of the Lease is amended by deleting in line 3 174,982
Square Feet on the Upper Lobby Level, the 2nd through 8th Floors (inclusive) and
the 10th, 14th, 15th and 17th Floors and inserting in lieu thereof 176,363
Square Feet on the Upper Lobby Level, the 2nd through 8th Floors (inclusive) and
the 10th, 14th, 15th and 17th Floors; and

D. Section 2(a)(viii) of the Lease is amended by striking 174,982 in line 1 and
inserting in lieu thereof 176,363; and

E. Section 2(a)(ix) of the Lease is amended by striking 16.93 in line 1 and
inserting in lieu thereof 17.06; and

F. Section 26.A. of the Lease is amended by striking 24,000 and inserting in
lieu thereof 22,619.

             VI.  Base Rent.

             The total Base Rent of $70,881,463.20 payable as set forth in
Section 1 of the Lease is amended to be a total Base Rent of $72,670,748.06 as
set forth in said Section 1 of the Lease except monthly installments of Base
Rent shall be payable as follows:

                                       3
<PAGE>

A. six (6) equal monthly installments of $300,895.55 to be paid in advance on or
before the first day of each month during the period beginning December 1, 1983
and ending May 31, 1984; and

B. twenty-two (22) equal monthly installments of $307,188.24 to be paid in
advance on or before the first day of each month during the period beginning
June 1, 1984 and ending March 31, 1986; and

C. twelve (12) equal monthly installments of $306,600.99 to be paid in advance
on or before the first day of each month during the period beginning April 1,
1986 and ending March 31, 1987; and

D. eighty (80) equal monthly installments of $308,931.43 to be paid in advance
on or before the first day of each month during the period beginning April 1,
1987 and ending November 30, 1993; and

E. one hundred twenty (120) equal monthly installments of $297,612.56 to be paid
in advance on or before the first day of each month during the period beginning
December 1, 1993 and ending November 30, 2003.

             VII. Preparation of the Fourth Additional Space.

             Landlord agrees to prepare the Fourth Additional Space in
accordance with the terms of the Work Letter attached to the Lease and dated May
11, 1981 providing the Building Standard Work installation of Landlord as
described on Attachment "A" of said Work Letter.

             VIII.Condition of the Fifth Additional Space.

             Tenant agrees to accept the Fifth Additional Space (including
improvements and personality, if any) in its condition and as-built
configuration existing on the earlier of the date Tenant takes possession of the
Fifth Additional Space or April 1, 1987.

             IX.  Estoppel Certificates.

             Tenant agrees, upon the occupancy of the Fourth Additional Space,
to execute Estoppel Certificates in the form of attached "D" as required by
Teachers Insurance and Annuity Association of America.

                                       4
<PAGE>

             X.   TERMS OF LEASE.

             Except as herein modified or amended, the provisions, conditions
and terms of the Lease shall remain unchanged and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Tenth Amendment as of
the date first above written.

This instrument is executed by AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee, as aforesaid. All the covenants
and conditions to be performed hereunder by AMERICAN NATIONAL BANK AND TRUST
COMPANY OF CHICAGO are undertaken by it solely as Trustee, as aforesaid and not
individually, and no personal liability shall be asserted or be enforceable
against AMERICAN NATIONAL BANK AND TRUST COMPANY OF CHICAGO by reason of any of
the covenants, statements, representations or warranties contained in this
instrument.

                                                   LANDLORD

                                  AMERICAN NATIONAL BANK AND TRUST COMPANY OF
                                  CHICAGO, ILLINOIS, a national banking
                                  association of Chicago, Illinois, not
                                  individually but solely as Trustee under the
                                  provisions of a certain Trust Agreement dated
                                  March 20, 1980, and known as Trust No. 48268.

ATTEST:

By /s/                            By /s/
  ----------------------------      ---------------------------
  Title  SECOND VICE PRESIDENT    Title  SECOND VICE PRESIDENT
       -----------------------           ----------------------

                                                 TENANT

                                  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                  not-for-profit corporation

ATTEST OR WITNESS:

By /s/                            By /s/
  --------------------------        ---------------------------
  Title  CONTROLLER                 Title SENIOR VICE PRESIDENT
       ---------------------             ----------------------

                                       5
<PAGE>

                               ELEVENTH AMENDMENT

        This Eleventh Amendment (the "Amendment") is made and entered into as of
February 1, 1999, but and between EOP-10 & 30 SOUTH WACKER, L.L.C., a Delaware
limited liability company, as beneficiary of land trust dated October 1, 1997,
and known as American National Bank and Trust Company of Chicago Trust No.
123434-06 ("Landlord"), and CHICAGO MERCANTILE EXCHANGE, an Illinois
not-for-profit corporation ("Tenant").

                                   WITNESSETH

A.      WHEREAS, Landlord (as successor in interest to American National Bank
        and Trust Company of Chicago, Illinois, a national banking association
        of Chicago, Illinois not individually but solely as Trustee under the
        provisions of a certain Trust Agreement dated March 20, 1980, and known
        as Trust No. 48268) and Tenant are parties to that certain lease dated
        the 11th day of May, 1981, for space currently containing approximately
        176,363 rentable square feet (the "Current Premises") on the upper lobby
        level, 2nd through 8th, 10th, 14th, 15th and 17th floors of the building
        commonly known as 30 South Wacker Drive and the address of which is 30
        South Wacker Drive, Chicago, Illinois (the "Building"), which lease has
        been previously amended by instruments dated February 1, 1982 ("First
        Amendment"), April 26, 1982 ("Second Amendment"), June 29, 1982 ("Third
        Amendment"), July 28, 1982 ("Fourth Amendment"), October 7, 1982 ("Fifth
        Amendment"), July 5, 1982 ("Sixth Amendment"), September 19, 1982
        ("Seventh Amendment"), October 17, 1983 ("Eighth Amendment"), December
        3, 1984 ("Ninth Amendment"), and March 16, 1987 ("Tenth Amendment")
        (collectively, the "Lease"); and

B.      WHEREAS, Tenant has requested that additional space known as Suite No.
        2003 containing approximately 2,783 rentable square feet on the 20th
        floor of the Building shown on Exhibit A hereto (the "2003 Temporary
        Space") be added to the Premises on a temporary basis and that the Lease
        be appropriately amended and Landlord is willing to do the same on the
        terms and conditions hereinafter set forth;

C.      WHEREAS, Tenant has requested that additional space known as Suite No.
        3301 containing approximately 3,241 rentable square feet on the 33rd
        floor of the Building shown on Exhibit B hereto (the "3301 Temporary
        Space") be added to the Premises on a temporary basis and that the Lease
        be appropriately amended and Landlord is willing to do the same on the
        terms and conditions hereinafter set forth;

D.      WHEREAS, Tenant has requested that additional space containing
        approximately 23,791 rentable square feet on the ninth (9th) floor of
        the Building shown on Exhibit C hereto (the "9th Floor Expansion Space")
        be added to the Premises and that the Lease be appropriately amended and
        Landlord is willing to do the same on the terms and conditions
        hereinafter set forth;

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

        I.   Temporary Expansion and Effective Dates.

             A.   2003 Temporary Space.  For the period commencing on January 1,
                  1999 (the "2003 Temporary Expansion Effective Date") and
                  ending on May 31, 1999 (the "2003 Temporary Expansion
                  Termination Date") (said period between the 2003 Temporary
                  Expansion Effective Date and the 2003 Temporary Expansion
                  Termination Date being referred to herein as the "2003
                  Expansion Term"), the Premises, as defined in the Lease, is
                  temporarily increased by 2,783 rentable square feet by the
                  addition of the 2003 Temporary Space, and during the 2003
                  Expansion Term the 2003 Temporary Space shall be deemed part
                  of the Premises, as defined in the Lease.  The 2003 Temporary
                  Space is subject to all the terms and conditions of the Lease
                  except as expressly modified herein and except that Tenant
                  shall not be entitled to receive any allowances, abatement or
                  other financial concession granted with respect to any other
                  portion of the Premises unless such concessions are expressly
                  provided for herein with respect to the 2003 Temporary
                  Expansion Space.
<PAGE>

        B.   3301 Temporary Space.  For the period commencing on February 1,
             1999 (the "3301 Temporary Expansion Effective Date") and ending on
             the last day of the calendar month designated by Landlord or Tenant
             in a notice of termination given no later than thirty (30) days
             prior to the designated date of termination, (the "3301 Temporary
             Expansion Termination Date"), which 3301 Temporary Expansion
             Effective date shall, in no event be prior to July 31, 1999 (said
             period between the 3301 Temporary Expansion Effective Date and the
             3301 Temporary Expansion Termination Date being referred to herein
             as the "3301 Expansion Term"), the Premises, as defined in the
             Lease, is temporarily increased by 3,241 rentable square feet by
             the addition of the 3301 Temporary Space, and during the 3301
             Temporary Expansion Space Term the 3301 Temporary Expansion Space
             shall be deemed part of the Premises, as defined in the Lease.  The
             3301 Temporary Space is subject to all the terms and conditions of
             the Lease except as expressly modified herein and except that
             Tenant shall not be entitled to receive any allowances, abatement
             or other financial concession granted with respect to any other
             portion of the Premises unless such concessions are expressly
             provided for herein with respect to the 3301 Temporary Expansion
             Space.

        C.   9th Floor Expansion Space.  Effective as of the Expansion Effective
             Date (as hereinafter defined) the Premises, as defined in the
             Lease, is increased by 23,791 rentable square feet by the addition
             of the Expansion Space, and from and after the Expansion Effective
             Date, the Premises, as defined in the Lease, shall be deemed to
             include the 9th Floor Expansion Space.  The Lease Term for the 9th
             Floor Expansion Space shall commence on the Expansion Effective
             Date and end on the Termination Date.  The 9th Floor Expansion
             Space is subject to all the terms and conditions of the Lease
             except as expressly modified herein and except that Tenant shall
             not be entitled to receive any allowances, abatements or other
             financial concessions granted with respect to the Premises unless
             such concessions are expressly provided for herein with respect to
             the 9th Floor Expansion Space.

             1.   The Expansion Effective Date shall be July 1, 1999 (the
                  "Target Expansion Effective Date"), or such later date as
                  possession is delivered to Tenant pursuant to clause 2 below.

             2.   The Expansion Effective Date shall be delayed on a day for day
                  basis to the extent that Landlord fails to deliver possession
                  of the Expansion Space on or before April 1, 1999, for any
                  reason, including but not limited to, holding over by prior
                  occupants.  Any such delay in the Expansion Effective Date
                  shall not subject Landlord to any liability for any loss or
                  damage resulting therefrom.  Notwithstanding the foregoing,
                  Landlord will use commercially reasonable efforts to obtain
                  possession of the Expansion Space from the prior occupants,
                  and Tenant will cooperate with Landlord in connection with
                  such efforts.  If the Expansion Effective Date is delayed, the
                  Termination Date under the Lease shall not be similarly
                  extended.  If the Expansion Effective Date is delayed beyond
                  September 1, 1999 (the "Outside Expansion Date"), and Tenant
                  has cooperated with Landlord in connection with Landlord's
                  efforts to obtain possession as set forth above, then Tenant,
                  as its sole remedy (provided Landlord has used commercially
                  reasonable efforts to obtain possession of the Expansions
                  Space from the prior occupants as set forth above), may
                  terminate this Amendment as to the Expansion Space by giving
                  Landlord written notice of termination on or before the date
                  Landlord has tendered possession of the Expansion Space to
                  Tenant.

II.     Monthly Base Rent

        A.   2003 Temporary Space.  Tenant shall not be obligated to pay Base
             Rent or Rent Adjustment for the 2003 Temporary Space during the
             2003 Temporary Expansion Space Term; however, if Tenant holds over
             in the

                                       2
<PAGE>

                  2003 Temporary Space beyond the 2003 Temporary Expansion Space
                  Term, Tenant's holdover rent shall be calculated in accordance
                  with the provisions of the Lease but assuming that Base Rent
                  for the 2003 Expansion Space was Four Thousand Six Hundred
                  Thirty Eight and 33/100 Dollars ($4,638.33) per month.

             B.   3301 Temporary Space.  In addition to Tenant's obligation to
                  pay Base Rent for the Current Premises, and, as applicable,
                  the 9th Floor Expansion Space, during the 3301 Temporary
                  Expansion Space Term, Tenant shall pay Landlord the sum of
                  Nine Thousand Five Hundred and No/100 Dollars ($9,500.00) per
                  month as Base Rent for the 3301 Temporary Space hereunder,
                  with each such installment payable on or before the first day
                  of each month during the period beginning on the 3301
                  Temporary Expansion Effective Date and ending on the 3301
                  Temporary Expansion Termination Date hereunder, prorated for
                  any partial month within the 3301 Temporary Expansion Space
                  Term.  Tenant shall not be responsible for any Rent Adjustment
                  with respect to the 3301 Temporary Expansion Space, including
                  Expenses or Taxes.

             C.   9th Floor Expansion Space. In addition to Tenant's obligation
                  to pay Base Rent for the Current Premises and the 3301
                  Temporary Space, Tenant shall pay Landlord the sum of One
                  Million Nine Hundred Three Thousand Eight Hundred Sixty Three
                  and 12/100 Dollars ($1,903,863.12) as Base Rent for the
                  Expansion Space in fifty three (53) monthly installments as
                  follows:

                  1.  Twelve (12) equal installments of Thirty Four Thousand One
                      Hundred and 43/100 Dollars ($34,100.43) each payable on or
                      before the first day of each month during the period
                      beginning on the Expansion Effective Date and ending June
                      30, 2000.

                  2.  Twelve (12) equal installments of Thirty Five Thousand One
                      Hundred Twenty Three and 44/100 Dollars ($35,123.44) each
                      payable on or before the first day of each month during
                      the period beginning July 1, 2000 and ending June 30,
                      2001.

                  3.  Twelve (12) equal installments of Thirty Six Thousand One
                      Hundred Seventy Seven and 14/100 Dollars ($36,177.14) each
                      payable on or before the first day of each month during
                      the period beginning July 1, 2001 and ending June 30,
                      2002.

                  4.  Twelve (12) equal installments of Thirty Seven Thousand
                      Two Hundred Sixty Two and 45/100 Dollars ($37,262.45) each
                      payable on or before the first day of each month during
                      the period beginning July 1, 2002 and ending June 30,
                      2003.

                  5.  Five (5) equal installments of Thirty Eight Thousand Three
                      Hundred Eighty and 32/100 Dollars ($38,380.32) each
                      payable on or before the first day of each month during
                      the period beginning July 1, 2003 and ending November 30,
                      2003.

             All such Base Rent shall be payable by Tenant in accordance with
             the terms of Section 1 of the Lease. Landlord and Tenant
             acknowledge that the foregoing schedule is based on the assumption
             that the Expansion Effective Date is the Target Expansion Effective
             Date. If the Expansion Effective Date is other than the Target
             Expansion Effective Date, the schedule set forth above with respect
             to the payment of any installment(s) of Base Rent for the Expansion
             Space shall be appropriately adjusted on a per diem basis to
             reflect the actual Expansion Effective Date and the actual
             Expansion Effective Date shall be set forth in a confirmation
             letter to be prepared by Landlord. In such event, the effective
             date of any increases in the Base Rental rate shall be similarly
             postponed as a result of an adjustment of the Expansion Effective
             Date as provided above.

        III. Tenant's Proportion and Rent Adjustments.  For the period
             commencing with the 9th Floor Expansion Effective Date and ending
             on the Termination Date,

                                       3
<PAGE>

             Tenant's Proportion for the 9th Floor Expansion Space is two and
             three thousand seventeen ten-thousandths percent (2.3017%). For the
             period commencing with the 9th Floor Expansion Effective Date and
             ending on the Termination Date, Tenant shall pay for its Proportion
             of Expenses and Taxes applicable to the Expansion Space in
             accordance with the terms of the Lease, provided, however, with
             respect to the Expansion Space only, during such period, Section
             2(d) of the Lease is hereby amended by striking "$5,684,954.00" and
             inserting in lieu thereof "$0.00".

                                       4
<PAGE>

        IV.  Improvements

             A.   Condition. Tenant has inspected the 2003 Temporary Space, the
                  3301 Temporary Space and the 9th Floor Expansion Space and
                  agrees to accept the same "as is" as of the date of this
                  Amendment (ordinary wear and tear excepted) without any
                  agreements, representations, understandings or obligations on
                  the part of Landlord to perform any alterations, repairs or
                  improvements.

             B.   Cost of Improvements. Any construction, alterations or
                  improvement made to the 2003 Temporary Space, the 3301
                  Temporary Space and the 9th Floor Expansion Space shall be
                  made at Tenant's sole cost and expense.

             C.   Responsibility for Improvements.  Any construction,
                  alterations or improvements to the 2003 Temporary Space, the
                  3301 Temporary Space and the 9th Floor Expansion Space shall
                  be performed by Tenant using contractors selected by Tenant
                  and approved by Landlord and shall be governed in all respects
                  by the provisions of Section 8 of the Lease.  In any and all
                  events, neither the Temporary Expansion Effective Date nor the
                  Expansion Effective Date shall be postponed or delayed if the
                  initial improvements to the Temporary Expansion Space or the
                  Expansion Space are incomplete on the respective Expansion
                  Effective Dates for any reason whatsoever.  Any delay in the
                  completion of initial improvements to the Temporary Expansion
                  Space or Expansion Space shall not subject Landlord to any
                  liability for any loss or damage resulting therefrom.

        V.   Early Access.  Provided that the 9th Floor Expansion Space has been
             vacated by the current tenant thereof, Tenant may occupy the 9th
             Floor Expansion Space from and after April 1, 1999. During any
             period that Tenant shall be permitted to take possession of the 9th
             Floor Expansion Space prior to the Expansion Effective Date, Tenant
             shall comply with all the terms and provisions of the Lease, except
             those provisions requiring payment of Base Rent or Rent Adjustments
             as to the 9th floor Expansion Space.  Landlord will tender
             possession of the 9th Floor Expansion Space to Tenant immediately
             after Landlord obtains such possession from the current tenant in
             said space.

        VI.  No Extension or Expansion Options. The parties hereto acknowledge
             and agree that any option or other rights contained in the Lease
             which entitle Tenant to extend the term of the Lease or expand the
             Premises shall apply only to the Premises and shall not be
             applicable to the 2003 Temporary Space or the 3301 Temporary Space
             in any manner.

        VII. Holdover. If Tenant should holdover in the 2003 Temporary Space or
             the 3301 Temporary Space after expiration or termination of the
             applicable term, any remedies available to Landlord as a
             consequence of such holdover contained in Section 17 of the Lease
             or otherwise shall be applicable, but only with respect to the
             applicable temporary space and shall not be deemed applicable to
             the Premises unless and until Tenant holds over in the Premises
             after expiration or earlier termination of the Lease Term.

        VIII. Miscellaneous.

             A.   This Amendment sets forth the entire agreement between the
                  parties with respect to the matter set forth herein. There
                  have been no additional oral or written representations or
                  agreements. Under no circumstances shall Tenant be entitled to
                  any Rent abatement, improvement allowance, leasehold
                  improvements, or other work to the Premises, or any similar
                  economic incentives that may have been provided Tenant in
                  connection with entering into the Lease, unless specifically
                  set forth in this Amendment.

             B.   Except as herein modified or amended, the provisions,
                  conditions and terms of the Lease shall remain unchanged and
                  in full force and effect.

                                       5
<PAGE>

             C.   In the case of any inconsistency between the provisions of the
                  Lease and this Amendment, the provisions of this Amendment
                  shall govern and control.

             D.   Submission of this Amendment by Landlord is not an offer to
                  enter into this Amendment but rather is a solicitation for
                  such an offer by Tenant. Landlord shall not be bound by this
                  Amendment until Landlord has executed and delivered the same
                  to Tenant.

             E.   The capitalized terms used in this Amendment shall have the
                  same definitions as set forth in the Lease to the extent that
                  such capitalized terms are defined therein and not redefined
                  in this Amendment.

             F.   Tenant hereby represents to Landlord that Tenant has dealt
                  with no broker except for the Levy Organization ("Broker") in
                  connection with this Amendment.  Tenant agrees to indemnify
                  and hold Landlord, its members, principals, beneficiaries,
                  partners, officers, directors, employees, mortgagee(s) and
                  agents, and the respective principals and members of any such
                  agents (collectively, the "Landlord Related Parties") harmless
                  from all claims of any brokers, other than Broker, claiming to
                  have represented Tenant in connection with this Amendment.
                  Landlord hereby represents to Tenant that Landlord has dealt
                  with no broker in connection with this Amendment.  Landlord
                  agrees to indemnify and hold Tenant, its members, principals,
                  beneficiaries, partners, officers, directors, employees, and
                  agents, and the respective principals and members of any such
                  agents (collectively, the "Tenant Related Parties") harmless
                  from all claims of any brokers claiming to have represented
                  Landlord in connection with this Amendment.

        IN WITNESS WHEREOF, Landlord and Tenant have duly executed this
Amendment as of the day and year first above written.

                            LANDLORD:  EOP-10&30 SOUTH WACKER, L.L.C., a
                                       Delaware limited liability company, as
                                       beneficiary of land trust dated October
                                       1, 1997, and known as American national
                                       Bank and Trust Company of Chicago Trust
                                       No. 123434-06

                                  By:  EOP Operating Limited Partnership, a
                                       Delaware limited partnership, its sole
                                       member

                                       By:  Equity Office Properties Trust, a
                                            Maryland real estate investment
                                            trust, its managing general partner

                                            By: /s/ George Kohl
                                               -----------------------------
                                            Name:       George Kohl
                                                 ---------------------------
                                            Title:  Vice President Leasing
                                                  --------------------------

                            TENANT:  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                     not-for-profit corporation

                                  By: /s/ David G. Gomach
                                     ---------------------------------------
                                  Name:   David G. Gomach
                                       -------------------------------------
                                  Title: Senior Vice President CFO
                                        ------------------------------------

                                       6
<PAGE>

                                TWELFTH AMENDMENT

        This Twelfth Amendment (the "Amendment") is made and entered into as of
Jun 30 1999, 1999, by and between EOP-10 & 30 SOUTH WACKER, L.L.C., a Delaware
limited liability company, as beneficiary of land trust dated October 1, 1997,
and know as American National Bank and Trust company of Chicago Trust No.
123434-06 ("Landlord"), and CHICAGO MERCANTILE EXCHANGE, an Illinois
not-for-profit corporation ("Tenant").

                                   WITNESSETH

A.      WHEREAS, Landlord (as successor in interest to American National Bank
        and Trust Company of Chicago, Illinois, a national banking association
        of Chicago, Illinois, not individually but solely as Trustee under the
        provisions of a certain Trust Agreement dated March 20, 1980, and known
        as Trust No. 48268) and Tenant are parties to that certain lease dated
        the 11th day of May, 1981, for space (the "Current Premises") in the
        building commonly known as 30 South Wacker Drive and the address of
        which is 30 South Wacker Drive, Chicago, Illinois (the "Building"),
        which lease has been previously amended by instruments dated February 1,
        1982 ("First Amendment"), April 26, 1982 ("Second Amendment"), June 29,
        1982 ("Third Amendment), July 28, 1982 ("Fourth Amendment"), October 7,
        1982 ("Fifth Amendment"), July 5, 1983 ("Sixth Amendment"), September
        19, 1983 ("Seventh Amendment"), October 17, 1983 ("Eighth Amendment"),
        December 3, 1984 ("Ninth Amendment"), March 16, 1987 ("Tenth
        Amendment"), and February 1, 1999 (the "Eleventh Amendment")
        (collectively the "Lease"); and

B.      WHEREAS, Tenant has requested that storage space known as M-208
        containing approximately 1,060 rentable square feet and M-210 containing
        approximately 1,275 rentable square feet on the Mezzanine floor of the
        Building shown on Exhibit A hereto (the "Storage Space") be added to the
        Premises and that the Lease be appropriately amended and Landlord is
        willing to do the same on the terms and conditions hereinafter set
        forth;

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

        I.   Storage Effective Date.  Effective as of the Storage Effective Date
             (as hereinafter defined) the Premises, as defined in the Lease, is
             increased by 2,335 rentable square feet by the addition of the
             Storage Space, and from and after the Storage Effective Date, the
             Premises, as defined in the Lease, shall be deemed to include the
             Storage Space.  The Lease Term for the Storage Space shall commence
             on the Storage Effective Date and end on the Termination Date. The
             Storage Space is subject to all the terms and conditions of the
             Lease except as expressly modified herein and except that Tenant
             shall not be entitled to receive any allowances, abatements or
             other financial concessions granted with respect  to the Premises
             unless such concessions are expressly provided for herein with
             respect to the Storage Space.

             1.   The Storage Effective Date shall be July 1, 1999 (the "Target
                  Storage Effective Date"), or such later date as possession is
                  delivered to Tenant. The Storage Space is currently vacant and
                  Landlord will deliver possession of the Storage Space to
                  Tenant upon full execution of this Amendment.

             2.   The Storage Effective Date shall be delayed on a day for day
                  basis to the extent that Landlord fails to deliver possession
                  of the Storage Space on or before July 1, 1999.  If the
                  Storage Effective Date is delayed, the Termination Date under
                  the Lease shall not be similarly extended.  If the Storage
                  Effective Date is delayed beyond September 1, 1999 (the
                  "Outside Storage Date"), then Tenant, as its sole remedy may
                  terminate this Amendment as to the Storage Space by giving
                  Landlord written notice of termination on or before the date
                  Landlord has tendered possession of the Storage Space to
                  Tenant.
<PAGE>

        II.  Monthly Storage Rent. In addition to Tenant's obligation to pay
             Base Rent for the Current Premises, Tenant shall pay Landlord the
             sum of One Hundred Sixty Two Thousand Nine Hundred Fifty Six and
             80/100 Dollars ($162,956.80) as Storage Rent for the Storage Space
             in fifty three (53) monthly installments as follows:

             1.   Twelve (12) equal installments of Two Thousand Nine Hundred
                  Eighteen and 75/100 Dollars ($2,918.75) each payable on or
                  before the first day of each month during the period beginning
                  on the Storage Effective Date and ending June 30, 2000.

             2.   Twelve (12) equal installments of Three Thousand Six and
                  31/100 Dollars ($3,006.31) each payable on or before the first
                  day of each month during the period beginning July 1, 2000 and
                  ending June 30, 2001.

             3.   Twelve (12) equal installments of Three Thousand Ninety Six
                  and 50/100 Dollars ($3,096.50) each payable on or before the
                  first day of each month during the period beginning July 1,
                  2001 and ending June 30, 2002.

             4.   Twelve (12) equal installments of Three Thousand One Hundred
                  Eighty Nine and 39/100 Dollars ($3,189.39) each payable on or
                  before the first day of each month during the period beginning
                  July 1, 2002 and ending June 30, 2003.

             5.   Five (5) equal installments of Three Thousand Two Hundred
                  Eighty Five and 08/100 Dollars ($3,285.08) each payable on or
                  before the first day of each month during the period beginning
                  July 1, 2003 and ending November 30, 2003.

             All such Storage Rent shall be payable by Tenant in accordance with
             the terms of Section 1 of the Lease. Landlord and Tenant
             acknowledge that the foregoing schedule is based on the assumption
             that the Storage Effective Date is the Target Storage Effective
             Date. If the Storage Effective Date is other than the Target
             Storage Effective Date, the schedule set forth above with respect
             to the payment of any installment(s) of Storage Rent for the
             Storage Space shall be appropriately adjusted on a per diem basis
             to reflect the actual Storage Effective Date and the actual Storage
             Effective Date shall be set forth in a confirmation letter to be
             prepared by Landlord. In such event, the effective date of any
             increases in the Storage Rent rate shall be similarly postponed as
             a result of an adjustment of the Storage Effective Date as provided
             above.

        III. Rent Adjustments. Tenant shall not be obligated to pay Rent
             Adjustment for the Storage Space. The addition of the Storage Space
             to the Premises shall not affect Tenant's Proportion or be included
             in the Rentable Area of the Premises for purposes of calculating
             the CPI portion of the Rent Adjustment or any other Rent
             Adjustment. However, Tenant shall pay to Landlord, as additional
             rent, all charges for any miscellaneous services, goods or
             materials furnished by Landlord at Tenant's request which are not
             required to be furnished by Landlord under the Lease.

        IV.  Improvements

             A.   Condition. Tenant has inspected the Storage Space and agrees
                  to accept the same "as is" as of the date of this Amendment
                  (ordinary wear and tear excepted) without any agreements,
                  representations, understandings or obligations on the part of
                  Landlord to perform any alterations, repairs or improvements.

             B.   Cost of Improvements. Any construction, alterations or
                  improvement made to the Storage Space shall be made at
                  Tenant's sole cost and expense.

                                       2
<PAGE>

             C.   Responsibility for Improvements. Any construction, alterations
                  or improvements to the Storage Space shall be performed by
                  Tenant using contractors selected by Tenant and approved by
                  Landlord and shall be governed in all respects by the
                  provisions of Section 9 of the Lease.

        V.   Early Access. Tenant may occupy the Storage Space from and after
             the full execution of this Amendment. During any period that Tenant
             shall be permitted to take possession of the Storage Space prior to
             the Storage Effective Date, Tenant shall comply with all the terms
             and provisions of the Lease, except those provisions requiring
             payment of Base Rent as to the Storage Space.

        VI.  Additional Storage Space Rules.

             A.   The Storage Space shall be used by Tenant for the storage of
                  equipment, inventory or other non-perishable items normally
                  used in Tenant's business, and for no other purpose
                  whatsoever.  Tenant agrees to keep the Storage Space in a net
                  and orderly fashion and to keep all stored items in cartons,
                  file cabinets or other suitable containers.  Tenant shall not
                  store anything in the Storage Space which is unsafe or which
                  otherwise may create a hazardous condition, or which may
                  increase Landlord's insurance rates, or cause a cancellation
                  or modification of Landlord's insurance coverage.  Without
                  limitation, Tenant shall not store any flammable, combustible
                  or explosive fluid, chemical or substance nor any perishable
                  food or beverage products, except with Landlord's prior
                  written approval. Landlord reserves the right to adopt and
                  enforce reasonable rules and regulations governing the use of
                  the Storage Space from time to time.

             B.   All terms and provisions of the Lease shall be applicable to
                  this Agreement, including, without limitation, Indemnity and
                  Waiver of Claims and Tenant's Insurance, except that Landlord
                  need not supply air-cooling, heat, water, janitorial service,
                  cleaning or window washing to the Storage Space.

             C.   At any time and from time to time, Landlord shall have the
                  right to relocate the Storage Space to a new location which
                  shall be no smaller than the square footage of the Storage
                  Space.

        VII. Miscellaneous.

             A.   This Amendment sets forth the entire agreement between the
                  parties with respect to the matter set forth herein.  There
                  have been no additional oral or written representations or
                  agreements.  Under no circumstances shall Tenant be entitled
                  to any Rent abatement, improvement allowance, leasehold
                  improvements, or other work to the Premises, or any similar
                  economic incentives that may have been provided Tenant in
                  connection with entering into the Lease, except as provided in
                  the case of casualty or eminent domain or as specifically set
                  forth in this Amendment.

             B.   Except as herein modified or amended, the provisions,
                  conditions and terms of the Lease shall remain unchanged and
                  in full force and effect.

             C.   In the case of any inconsistency between the provisions of the
                  Lease and this Amendment, the provisions of this Amendment
                  shall govern and control.

             D.   Submission of this Amendment by Landlord is not an offer to
                  enter into this Amendment but rather is a solicitation for
                  such an offer by Tenant. Landlord shall not be bound by this
                  Amendment until Landlord has executed and delivered the same
                  to Tenant.

             E.   The capitalized terms used in this Amendment shall have the
                  same definitions as set forth in the Lease to the extent that
                  such capitalized terms are defined therein and not redefined
                  in this Amendment.

             F.   Tenant hereby represents to Landlord that Tenant has dealt
                  with no broker except for the Levy Organization ("Broker") in
                  connection with this

                                       3
<PAGE>

                  Amendment.  Tenant agrees to indemnify and hold Landlord, its
                  members, principals, beneficiaries, partners, officers,
                  directors, employees, mortgagee(s) and agents, and the
                  respective principals and members of any such agents
                  (collectively, the "Landlord Related Parties") harmless from
                  all claims of any brokers, including Broker, claiming to have
                  represented Tenant in connection with this Amendment. Landlord
                  hereby represents to Tenant that Landlord has dealt with no
                  broker in connection with this Amendment.  Landlord agrees to
                  indemnify and hold Tenant, its members, principals,
                  beneficiaries, partners, officers, directors, employees, and
                  agents, and the respective principals and members of any such
                  agents (collectively, the "Tenant Related Parties") harmless
                  from all claims of any brokers claiming to have represented
                  Landlord in connection with this Amendment.

        IN WITNESS WHEREOF, Landlord and Tenant have duly executed this
Amendment as of the day and year first above written.

                        LANDLORD:  EOP-10&30 SOUTH WACKER, L.L.C., a Delaware
                                   limited liability company, as beneficiary of
                                   land trust dated October 1, 1997, and known
                                   as American national Bank and Trust Company
                                   of Chicago Trust No. 123434-06

                              By:  EOP Operating Limited Partnership, a Delaware
                                   limited partnership, its sole member

                                   By:  Equity Office Properties Trust, a
                                        Maryland real estate investment trust,
                                        its managing general partner

                                        By: /s/ George Kohl
                                           -----------------------------
                                        Name:       George Kohl
                                             ---------------------------
                                        Title:  Vice President Leasing
                                              --------------------------

                        TENANT:  CHICAGO MERCANTILE EXCHANGE, an Illinois
                                     not-for-profit corporation

                              By: /s/ David G. Gomach
                                 ---------------------------------------
                              Name:   David G. Gomach
                                   -------------------------------------
                              Title: Senior Vice President CFO
                                    ------------------------------------

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