<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
                                    ------------------------------------