<PAGE>

                                                         Exhibit 10.4
                                               Chicago Mercantile Exchange Inc.
                                              Registration Statement on Form S-4



                          CHICAGO MERCANTILE EXCHANGE
                     SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
                     --------------------------------------

<PAGE>


                               TABLE OF CONTENTS
                               -----------------

SECTION 1.................................................................   1
     General..............................................................   1
          1.1.  History, Purpose and Effective Date.......................   1
          1.2.  Administration............................................   1
          1.3.  Plan Year.................................................   1
          1.4.  Source of Benefit Payments................................   1
          1.5.  Expenses..................................................   2
          1.6.  Effect on Other Benefit Plans.............................   2
          1.7.  Applicable Laws...........................................   2
          1.8.  Gender and Number.........................................   2
          1.9.  Notices...................................................   2
          1.10. Evidence..................................................   2
          1.11. Action by Exchange........................................   2

SECTION 2.................................................................   3
     Participation........................................................   3
          2.1.  Participant...............................................   3
          2.2.  Plan Not Contract of Employment...........................   3

SECTION 3.................................................................   3
     Plan Benefits........................................................   3
          3.1.  Deferred Compensation Accounts............................   3
          3.2.  Deferred Compensation Credits.............................   3
          3.3.  Adjustment of Accounts....................................   3

SECTION 4.................................................................   4
     Payment of Plan Benefits.............................................   4
          4.1.  Vesting...................................................   4
          4.2.  Termination of Employment.................................   4
          4.3.  Hardship Distribution.....................................   4
          4.4.  Designation of Beneficiary................................   5
          4.5.  Distributions to Disabled Persons.........................   5
          4.6.  Benefits May Not be Assigned..............................   5
          4.7.  Withholding for Tax Liability.............................   6

SECTION 5.................................................................   6
     Amendment and Termination............................................   6
          5.1.  Administrative Amendments.................................   6
          5.2.  Amendment and Termination.................................   6


                                      -i-
<PAGE>

                          CHICAGO MERCANTILE EXCHANGE
                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
                    --------------------------------------

                                   SECTION 1
                                   ---------

                                    General
                                    -------

     1.1.  History, Purpose and Effective Date. Chicago Mercantile Exchange
Supplemental Executive Retirement Plan (the "Plan") has been established by
Chicago Mercantile Exchange, an Illinois not-for-profit corporation (the
"Exchange"), effective as of January 1, 1993 (the "Effective Date") so that it
may provide its eligible key management employees with an opportunity to receive
additional retirement income from the Exchange. The Plan is intended to
constitute a plan maintained primarily for the purpose of providing deferred
compensation for a select group of management or highly compensated employees
within the meaning of sections 201(2), 301(a)(3) and 401(a)(1) of the Employee
Retirement Income Security Act of 1974 ("ERISA").

     1.2.  Administration. The Exchange is the Plan Administrator of the Plan.
The Plan Administrator may delegate all or any part of its responsibilities and
powers to any person or persons selected by it. Any such delegation may be
revoked at any time. Until the Plan Administrator takes action to the contrary,
the President of the Exchange shall be delegated the power and responsibility to
take all actions assigned to or permitted to be taken by the Plan Administrator
under sections 3 and 4 hereof. The Secretary of the Exchange (or, on behalf of
the Secretary of the Exchange, any corporate Secretary or Assistant Secretary)
shall certify to any interested person the names of the employees of the
Exchange who are, from time to time, authorized to act on behalf of the Plan
Administrator and who are responsible for the day-to-day operation and
administration of the Plan. Any interpretation of the Plan by the Plan
Administrator and any decision made by the Plan Administrator or its delegate on
any other matter within its discretion is final and binding on all persons.

     1.3.  Plan Year. The term "Plan Year" means the calendar year.

     1.4.  Source of Benefit Payments. Subject to the terms and conditions of
the Plan, any amount payable to or on account of a Participant under this Plan
shall be paid from the general assets of the Exchange or from one or more
trusts, the assets of which are subject to the claims of the Exchange's general
creditors. The amounts payable hereunder shall be reflected on the accounting
records of the Exchange but shall not be construed to create, or require the
creation of, a trust, custodial or escrow account. None of the individuals
entitled to benefits under the
<PAGE>

Plan shall have any preferred claim on, or any beneficial ownership interest in,
any assets of the Exchange or to any investment reserves, accounts, trusts or
funds that the Exchange may purchase, establish or accumulate to aid in
providing the benefits under the Plan, and any rights of such individuals under
the Plan or any such reserves, accounts, trusts or funds shall constitute
unsecured contractual rights only. Nothing contained in the Plan shall
constitute a guarantee by the Exchange that the assets of the Exchange shall be
sufficient to pay any benefits to any person. Nothing contained in the Plan and
no action taken pursuant to its provisions shall create a trust or fiduciary
relationship of any kind between the Exchange and an employee or any other
person.

     1.5.  Expenses. The expenses of administering the Plan shall be borne by
the Exchange.

     1.6.  Effect on Other Benefit Plans. Any amounts credited or paid under
this Plan shall not be considered to be compensation for the purposes of any
qualified plan (within the meaning of section 401(a) of the Internal Revenue
Code of 1986, as amended (the "Code")) maintained by the Exchange. The treatment
of such amounts under other employee benefit plans shall be pursuant to the
provisions of such plans.

     1.7.  Applicable Laws. The Plan shall be construed and administered in
accordance with the internal laws of the State of Illinois.

     1.8.  Gender and Number. Where the context admits, words in any gender
shall include any other gender, words in the singular shall include the plural
and the plural shall include the singular.

     1.9.  Notices. Any notice or document required to be given to or filed with
the Plan Administrator will be properly filed if delivered or mailed by
registered mail, postage prepaid, to the Secretary of the Exchange, at its
principal executive offices. The Plan Administrator may, by advance written
notice to affected persons, revise such notice procedure from time to time. Any
notice required under the Plan may be waived by the person entitled to notice.

     1.10.  Evidence. Evidence required of anyone under the Plan may be by
certificate, affidavit, document or other information which the person acting on
it considers pertinent and reliable, and signed, made or presented by the proper
party or parties.

     1.11.  Action by Exchange. Any action required or permitted to be taken by
the Exchange shall be by resolution of its Board of Governors, or by a duly
authorized officer of the Exchange.

                                      -2-
<PAGE>

                                   SECTION 2
                                   ---------

                                 Participation
                                 -------------

     2.1.  Participant. The key employees eligible to participate in the Plan
and the conditions for such participation shall be established, from time to
time, by the Exchange; provided, however, that Participants shall be limited to
a select group of management or highly compensated employees within the meaning
of sections 201(l), 301(a)(2) and 401(a)(1) of ERISA. If the Exchange
determines that participation by one or more Participants shall cause the Plan
to be subject to Part 2, 3 or 4 of Title I of ERISA, the entire interest of such
Participant or Participants under the Plan shall be immediately paid to such
Participant or shall otherwise be segregated from the Plan in the discretion of
the Exchange, and such Participant or Participants shall cease to have any
interest under the Plan.

     2.2.  Plan Not Contract of Employment. The Plan does not constitute a
contract of employment, and participation in the Plan will not give any employee
the right to be retained in the employ of the Exchange nor any right or claim to
any benefit under the Plan, unless such right or claim has specifically accrued
under the terms of the Plan.


                                   SECTION 3
                                   ---------

                                 Plan Benefits
                                 -------------

     3.1.  Deferred Compensation Accounts. The Plan Administrator shall
maintain, or cause to be maintained, an Account in the name of each Participant
which shall reflect the sum of the following amounts:

     (a)   the amount of "Deferred Compensation Credits" to be credited to the
           Participant's Account in accordance with subsection 3.2; and

     (b)   the assumed rate of earnings to be credited to the Participant's
           Account in accordance with subsection 3.3.

     3.2.  Deferred Compensation Credits. From time to time, the Executive
Committee of the Exchange shall determine, in its sole discretion, a uniform
percentage (if any) of base earnings that shall be awarded to each Participant
as Deferred Compensation Credits. The amount of Deferred Compensation Credits
awarded to a participant shall be credited to his Account as of the first
business day of the next Plan Year quarter.

     3.3.  Adjustment of Accounts. The amounts credited to a Participant's
Account in accordance with subsection 3.2 shall be

                                      -3-
<PAGE>

adjusted from time to time in accordance with uniform procedures established by
the Plan Administrator to reflect the value of an investment equal to the
Participant's Account balance in one or more assumed investments that the Plan
Administrator offers from time to time, and which the Participant directs the
Plan Administrator to use for purposes of adjusting his Account. Such amount
shall be determined without regard to taxes that would be payable with respect
to any such assumed investment. The Plan Administrator may eliminate any assumed
investment alternative at any time; provided, however, that the Plan
Administrator may not retroactively eliminate any assumed investment
alternative. To the extent permitted by the Plan Administrator, the Participant
may elect to have different portions of his Account balance for any period
adjusted on the basis of different assumed investments. Notwithstanding the
election by Participants of certain assumed investments and the adjustment of
their Accounts based on such investment decisions, the Plan does not require,
and no trust or other instrument maintained in connection with the Plan shall
require, that any assets or amounts which are set aside in trust or otherwise
for the purpose of paying Plan benefits shall actually be invested in the
investment alternatives selected by Participants.

                                   SECTION 4
                                   ---------

                           Payment of Plan Benefits
                           ------------------------

     4.1.  Vesting. A Participant shall have at all times a fully vested and
nonforfeitable interest in the amounts theretofore credited or required to be
credited to his Account under Section 3.

     4.2.  Termination of Employment. After a Participant's death or termination
of active employment, the Participant's entire Account balance shall be paid in
cash or in kind to or on account of the Participant as follows:

     (a)  in a single lump sum payment as soon as practicable after his death or
          other termination date occurs or

     (b)  if elected by the Participant, in annual installments over a period of
          5 or fewer years; provided, however, that any such election by a
          Participant who resigns or is dismissed prior to his retirement date
          (within the meaning of the Exchange's cash balance pension plan) shall
          require the consent of the Exchange.

     4.3.  Hardship Distributions. The Plan Administrator may, pursuant to rules
adopted by it and applied in a uniform manner, accelerate the date of
distribution of a Participant's Account because of Hardship at any time.
"Hardship" shall mean an

                                      -4-
<PAGE>

unforeseeable, severe financial condition resulting from (a) a sudden and
unexpected illness or accident of the Participant or his dependent (as defined
in section 152(a) of the Code); (b) loss of the Participant's property due to
casualty; or (c) other similar extraordinary and unforeseeable circumstances
arising as a result of events beyond the control of the Participant, but which
may not be relieved through other available resources of the Participant, as
determined by the Plan Administrator in accordance with uniform rules adopted by
it.

     4.4.  Designation of Beneficiary. Each Participant from time to time, by
signing a form furnished by the Plan Administrator, may designate any legal or
natural person or persons (who may be designated contingently or successively)
to whom his benefits under the Plan are to be paid if he dies before he receives
all of his benefits. A beneficiary designation form will be effective only when
the signed form is filed with the Plan Administrator while the Participant is
alive and will cancel all beneficiary designation forms filed earlier. Except as
otherwise specifically provided in this subsection 4.4, if a deceased
Participant failed to designate a beneficiary as provided above, or if the
designated beneficiary of a deceased Participant dies before him or before
complete payment of the Participant's benefits, his benefits shall be paid to
the legal representative or representatives of the estate of the last to die of
the Participant and his designated beneficiary.

     4.5.  Distributions to Disabled Persons. Not withstanding the provisions of
this Section 4, if, in the Plan Administrator's opinion, a Participant or
beneficiary is under a legal disability or is in any way incapacitated so as to
be unable to manage his financial affairs, the Plan Administrator may direct
that payment be made to a relative or friend of such person for his benefit
until claim is made by a conservator or other person legally charged with the
care of his person or his estate, and such payment shall be in lieu of any such
payment to such Participant or beneficiary. Thereafter, any benefits under the
Plan to which such Participant or beneficiary is entitled shall be paid to such
conservator or other person legally charged with the care of his person or his
estate.

     4.6.  Benefits May Not be Assigned. Neither the Participant nor any other
person shall have any voluntary or involuntary right to commute, sell, assign,
pledge, anticipate, mortgage or otherwise encumber, transfer, hypothecate or
convey in advance of actual receipt the amounts, if any, payable hereunder, or
any part hereof, which are expressly declared to be unassignable and non-
transferable. No part of the amounts payable shall be, prior to actual payment,
subject to seizure or sequestration for payment of any debts, judgements,
alimony or separate maintenance owed by the Participant or any other person, or
be transferred by

                                      -5-
<PAGE>

operation of law in the event of the Participant's or any other person's
bankruptcy or insolvency.

     4.7.  Withholding for Tax Liability. The Exchange may withhold or cause to
be withheld from any payment of benefits made pursuant to the Plan any taxes
required to be withheld and such sum as the Exchange may reasonably estimate to
be necessary to cover any taxes for which the Exchange may be liable and which
may be assessed with regard to such payment.

                                   SECTION 5
                                   ---------

                           Amendment and Termination
                           -------------------------

     5.1.  Administrative Amendments. The President of the Exchange may make
minor or administrative amendments to the Plan.

     5.2.  Amendment and Termination. The Exchange may amend or terminate the
Plan at any time; provided that it has made adequate provisions for any amount
payable by it under the terms of the Plan as in effect on the date it terminates
the Plan. Upon termination of the Plan, the Exchange may, in its discretion
applied in a uniform manner to all Participants, cause a lump sum payment of all
benefits for all Participants at substantially the same time.

     Dated this 23rd day of July, 1993.

                                CHICAGO MERCANTILE EXCHANGE



                                By /s/ Gerald Beyer
                                  ----------------------------------
                                Its Executive V.P. & CFO
                                   ---------------------------------

                                      -6-
<PAGE>

                                FIRST AMENDMENT
                                       TO
                          CHICAGO MERCANTILE EXCHANGE
                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
                    --------------------------------------

     Pursuant to the authority reserved to the Chicago Mercantile Exchange (the
"Exchange") by subsection 5.2 of the Chicago Mercantile Exchange Supplemental
Executive Retirement Plan (the "Plan") and exercised by the Executive Committee
of its Board of Governors, the Plan is amended, effective as of January 1, 1997,
in the following particulars:

     1.  By substituting the following for subsection 3.2 of the Plan:

     "3.2.  Deferred Compensation Credits. Unless otherwise determined by the
Executive Committee of the Exchange, for each Plan Year beginning on or after
January 1, 1996, 8 percent of each Participant's base earnings and bonus paid in
such Plan Year shall be awarded as Deferred Compensation Credits. The amount of
Deferred Compensation Credits awarded to a Participant for any such Plan Year
shall be credited to his Account as of the first business day of the next
following Plan Year."

     2.   By substituting the following for Section 4 of the Plan:

                             "SECTION 4
                             ----------

                     Payment of Plan Benefits
                     ------------------------

     4.1.  Vesting. A Participant shall have at all times a fully vested and
nonforfeitable interest in (i) the amount of any Deferred Compensation Credits
credited to the Participant's Account as of December 31, 1996, and (ii) any
assumed investment adjustment theretofore or thereafter credited with respect to
such Deferred Compensation Credits under subsection 3.3. A Participant shall
have a fully vested and nonforfeitable interest in the amount of any Deferred
Compensation Credits credited to the Participant's Account in accordance with
subsection 3.2 as of the first business day of any Plan Year beginning on or
after January 1, 1997 ("Post-1996 Credits"), and any assumed investment
adjustments thereon, as of the last day of the fourth Plan Year following the
Plan Year as of which such Deferred day Credits are credited to the
Participant's Account. Prior thereto, the amount of any Post-1996 Credits (and
any assumed investment adjustments thereon) shall be vested and nonforfeitable
as of the last day of the Plan Year that follows the Plan Year as of which such
Post-1996 Credits were credited to the Participant's Account by the number of
Plan Years determined in accordance with the following schedule:
<PAGE>

<TABLE>
<CAPTION>
Number of Plan Years following the         The vested percentage
Plan Year as of which the  Post-1996       shall be
Credits were credited to his Account       ---------------------
------------------------------------
<S>                                           <C>
three Plan Years                              66 2/3%
two Plan Years                                33 1/3%
one Plan Year                                      0%

     4.2.  Accelerated Vesting. Notwithstanding the provisions of subsection
4.1, if a Participant's termination of active employment with the Exchange
occurs on account of his death, retirement after attaining age 55 years and
completing 15 years of continuous service with the Exchange, or disability, the
amount of any Post-1996 Credits (and any assumed investment adjustments thereon)
not theretofore vested shall be vested and nonforfeitable as of the last day of
the Plan Year that follows the Plan Year as of which such Post-1996 Credits were
credited to the Participant's Account by the number of Plan Years determined in
accordance with the following schedule (in lieu of the schedule in subsection
4.1):

Number of Plan Years following             The vested percentage
the Plan Year as of which the              shall be
Post-1996 Credits were credited            ----------------------
to his Account
-------------------------------
<S>                                         <C>
four Plan Years                               100%
three Plan Years                               80%
two Plan Years                                 60%
one Plan Year                                  40%
</TABLE>

If a Participant's termination of active employment occurs under this subsection
4.2, the portion of any Post-1996 Credits (and any investment adjustments
thereon) that are not theretofore vested in accordance with subsection 4.1 or
the foregoing provisions of this subsection 4.2 and which shall be vested and
nonforfeitable as of the last day of the Plan Year in which credited to the
Participant's Account shall be twenty percent (20%).

     4.3.  Termination of Employment. After a Participant's death or termination
of active employment, the vested portion of the Participant's Account balance
shall be paid in cash or in kind to or on account of the Participant as follows:

     (a)  in a single lump sum payment as soon as practicable after his death or
          other termination date occurs, or

     (b)  if elected by the Participant, in annual installments over a period
          of 5 or fewer years; provided, however, that any such election by a
          Participant who resigns or

                                      -2-
<PAGE>

          is dismissed prior to his retirement date (within the meaning of the
          Exchange's cash balance pension plan) shall require the consent of the
          Exchange.

Any portion of his Account balance that is not vested in accordance with
subsection 4.1 or 4.2 at his termination of active employment shall be
forfeited.

     4.4.  Hardship Distributions. The Plan Administrator may, pursuant to rules
adopted by it and applied in a uniform manner, accelerate the date of
distribution of a Participant's vested Account because of Hardship at any time.
"Hardship" shall mean an unforeseeable, severe financial condition resulting
from (a) a sudden and unexpected illness or accident of the Participant or his
dependent (as defined in section 152(a) of the Code); (b) loss of the
Participant's property due to casualty; or (c) other similar extraordinary and
unforeseeable circumstances arising as a result of events beyond the control of
the Participant, but which may not be relieved through other available resources
of the Participant, as determined by the Plan Administrator in accordance with
uniform rules adopted by it.

     4.5.  Designation of Beneficiary. Each Participant from time to time, by
signing a form furnished by the Plan Administrator, may designate any legal or
natural person or persons (who may be designated contingently or successively)
to whom his vested benefits under the Plan are to be paid if he dies before he
receives all of his vested benefits. A beneficiary designation form will be
effective only when the signed form is filed with the Plan Administrator while
the Participant is alive and will cancel all beneficiary designation forms filed
earlier. Except as otherwise specifically provided in this subsection 4.5, if a
deceased Participant failed to designate a beneficiary as provided above, or if
the designated beneficiary of a deceased Participant dies before him or before
complete payment of the Participant's benefits, his benefits shall be paid to
the legal representative or representatives of the estate of the last to die of
the Participant and his designated beneficiary.

     4.6.  Distributions to Disabled Persons. Notwithstanding the provisions of
this Section 4, if, in the Plan Administrator's opinion, a Participant or
beneficiary is under a legal disability or is in any way incapacitated so as to
be unable to manage his financial affairs, the Plan Administrator may direct
that payment be made to a relative or friend of such person for his benefit
until claim is made by a conservator or other person legally charged with the
care of his person or his estate, and such payment shall be in lieu of any such
payment to such Participant or beneficiary. Thereafter, any benefits under the
Plan to which such Participant or beneficiary is entitled shall be paid to such

                                      -3-
<PAGE>

conservator or other person legally charged with the care of his person or his
estate.

     4.7.  Benefits May Not be Assigned. Neither the Participant nor any other
person shall have any voluntary or involuntary right to commute, sell, assign,
pledge, anticipate, mortgage or otherwise encumber, transfer, hypothecate or
convey in advance of actual receipt the amounts, if any, payable hereunder, or
any part hereof, which are expressly declared to be unassignable and non-
transferable. No part of the amounts payable shall be, prior to actual payment,
subject to seizure or sequestration for payment of any debts, judgements,
alimony or separate maintenance owed by the Participant or any other person, or
be transferred by operation of law in the event of the Participant's or any
other person's bankruptcy or insolvency.

     4.8.  Withholding for Tax Liability. The Exchange may withhold or cause to
be withheld from any payment of benefits made pursuant to the Plan any taxes
required to be withheld and such sum as the Exchange may reasonably estimate to
be necessary to cover any taxes for which the Exchange may be liable and which
may be assessed with regard to such payment."

     IN WITNESS WHEREOF, the undersigned officer of the Exchange has caused
these presents to be executed on behalf of the Exchange this 31st day of
December, 1996.

                              CHICAGO MERCANTILE EXCHANGE

                              By /s/ Paul B. O'Kelly,
                                 ----------------------------------------------
                                 Its Senior Vice President and General Counsel
                                     ------------------------------------------

                                      -4-
<PAGE>

                               SECOND AMENDMENT
                                    TO THE
                          CHICAGO MERCANTILE EXCHANGE
                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN

     Pursuant to the authority given to the President of the Exchange in Section
5.1 of the Plan to make minor or administrative Plan amendments, the Plan is
amended, effective December 1, 1997, in the following ways:

     1.   By substituting the following text for subsection 4.1 of the Plan:

     "4.1.  Vesting. A Participant shall have at all times a fully vested and
nonforfeitable interest in (i) the amount of any Deferred Compensation Credits
credited to the Participant's Account as of December 31, 1996, and (ii) any
assumed investment adjustment theretofore or thereafter credited with respect to
such Deferred Compensation Credits under subsection 3.3. A Participant shall
have a fully vested and nonforfeitable interest in the amount of any Deferred
Compensation Credits credited to the Participant's Account in accordance with
subsection 3.2 as of the first business day of any Plan Year beginning on or
after January 1, 1997 ("Post-1996 Credits"), and any assumed investment
adjustments thereon, as of December 10 of the fourth Plan Year following the
Plan Year as of which such Deferred Compensation Credits are credited to the
Participant's Account. Prior thereto, the amount of any Post-1996 Credits (and
any assumed investment adjustments thereon) shall be vested and nonforfeitable
as of December 10 of the Plan Year that follows the Plan Year as of which such
Post-1996 Credits were credited to the Participant's Account by the number of
Plan Years determined in accordance with the following schedule:

     Number of Plan Years following the      The vested percentage shall be
     Plan Year as of which the Post-1996     ------------------------------
     Credits were credited to his Account
     ------------------------------------

     Three Plan Years                        66 2/3%
     Two Plan Years                          33 1/3%
     One Plan Year                            0%"

     2.   By substituting the following text for subsection 4.2 of the Plan:

     "4.2.  Accelerated Vesting. Notwithstanding the provisions of subsection
4.1, if a Participant's termination of active employment with the Exchange
occurs on account of his death, retirement after attaining age 55 years and
completing 15 years of continuous service with the Exchange, or disability, the
amount of any Post-1996 Credits (and any assumed investment adjustments thereon)
not theretofore vested shall be vested and nonforfeitable as of December 10 of
the Plan Year that follows the Plan Year as of which such Post-1996 Credits were
credited to

<PAGE>

the Participant's Account by the number of Plan Years determined in accordance
with the following schedule (in lieu of the schedule in subsection 4.1):

     Number of Plan Years following the      The vested percentage shall be
     Plan Year as of which the Post-1996     ------------------------------
     Credits were credited to his Account
     ------------------------------------

     Four Plan Years                         100%
     Three Plan Years                         80%
     Two Plan Years                           60%
     One Plan Year                            40%

If a Participant's termination of active employment occurs under this subsection
4.2, the portion of any Post-1996 Credits (and any investment adjustments
thereon) that are not theretofore vested in accordance with subsection 4.1 or
the foregoing provisions of this subsection 4.2 and which shall be vested and
nonforfeitable as of December 10 of the Plan Year in which credited to the
Participant's Account shall be twenty percent (20%)."

     The undersigned officer of the Exchange has caused this amendment to be
executed on behalf of the President of the Exchange this 14th day of January,
1998.

                          CHICAGO MERCANTILE EXCHANGE

                          By: /s/ Paul B. O'Kelly
                              ---------------------------------------

                          Its:  Senior Vice President and General Counsel
<PAGE>

                               THIRD AMENDMENT
                                      TO
                          CHICAGO MERCANTILE EXCHANGE
                   SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
                   ----------------------------------------

     By virtue and in exercise of the amending authority reserved to the Chicago
Mercantile Exchange (the "Exchange") by the provisions of subsection 5.2 of the
Chicago Mercantile Exchange Supplemental Executive Retirement Plan (the "Plan"),
and pursuant to the authority delegated to the undersigned officer of the
Exchange by resolutions of its Board of Directors adopted on November 4, 1998
and November 16, 1998, the Plan is amended, effective as of November 16, 1998,
by adding the following new subsections to the Plan to follow immediately after
subsection 4.8 thereof.

     "4.9.  Cash-Out Election. Prior to a Participant's termination of active
employment with the Exchange, the Participant may make a one-time election (a
'Cash-Out Election') to have the entire nonforfeitable balance of his Account
distributed to him, in a single lump sum payment, in cash, within 15 days
following the date that such election is filed with the Exchange, subject to the
following:

     (a)  The Participant's nonforfeitable Account balance shall be determined
          under subsection 4.1 of the Plan as though the Participant had
          terminated from the employ of the Exchange on the date on which the
          Cash-Out Election is filed and, for this purpose, the accelerated
          vesting provisions of subsection 4.2 shall not apply even if the
          Participant has attained age 55 and completed 15 years of continuous
          service with the Exchange at the time of his election.

     (b)  The amount actually distributed to an electing Participant under this
          subsection 4.9 shall be equal to the Participant's nonforfeitable
          Account balance determined under subparagraph (a) next above, reduced
          by a penalty amount equal to 10 percent of such nonforfeitable Account
          balance. The 10 percent penalty amount shall be deducted from the
          Participant's Account and forfeited. The portion of the Participant's
          Account balance that is not distributable by reason of subsection 4.1
          or 4.2 shall then be treated as set forth in subsection 4.10.

     (c)  A Participant's Cash-Out Election shall not be effective unless the
          Participant makes a corresponding election under the Chicago
          Mercantile Exchange Senior Management Supplemental Deferred Savings
          Plan.

     4.10.  Forfeitures and Adjustments for Partial Distributions. In the event
that a Hardship Distribution under subsection 4.4 or a distribution pursuant to
a Cash-Out Election under subsection 4.9 is made with respect to any
Participant, the portion of his Account balance that is not distributable by
reason of subsection 4.1 or 4.2 (but not any vested amount that is forfeited as
a penalty under subsection 4.9) shall be credited to a "Subaccount" maintained
in the

<PAGE>

Participant's name which shall be adjusted from time to time in accordance with
subsection 3.3 based on the assumed investment alternatives selected by the
Participant thereunder. Upon the Participant's subsequent termination of
employment or any subsequent distribution to the Participant, the balance in
his Subaccount shall be treated as follows:

     (a)  If the Participant's subsequent termination of employment or
          distribution occurs after such Subaccount is fully vested and
          nonforfeitable in accordance with subsection 4.1 or 4.2, the balance
          of such Subaccount shall be distributable to or on behalf of the
          Participant in accordance with Section 4.

     (b)  If the Participant's subsequent termination of employment or
          distribution occurs before the balance of the Subaccount is fully
          vested, the nonforfeitable balance in the Subaccount shall be an
          amount determined as follows:

          (i)     first, an amount equal to the nonforfeitable balance of his
                  Account at the time of the previous Hardship Distribution or
                  Cash-out Election (including the 10 percent penalty amount in
                  the case of a Cash-out Election) shall be added to his
                  Subaccount balance;

          (ii)    next, his Subaccount balance, as adjusted under subparagraph
                  (i) next above, shall be reduced to an amount equal to the
                  product of such balance multiplied by his vested percentage
                  determined under subsection 4.1 or 4.2, as applicable, at the
                  time of the subsequent termination or distribution; and

          (iii)   finally, the adjusted Subaccount balance, as determined under
                  subparagraph (ii) next above, shall be reduced (but not below
                  zero) by an amount equal to the amount added to his Subaccount
                  balance under subparagraph (i) next above.

           The amount determined after the foregoing adjustments shall be
           nonforfeitable and distributable to or for his benefit in accordance
           with Section 4. The portion of his Subaccount balance, if any, which
           is not vested in accordance with this subsection 4.10 shall be
           forfeited if the Participant has terminated active employment with
           the Exchange, or, if the Participant's employment has not terminated,
           shall continue to be adjusted in accordance with subsection 3.3, and
           shall be further adjusted under this subsection 4.10 upon the
           Participant's subsequent termination of employment or any subsequent
           distribution in accordance with the terms of the Plan.

Notwithstanding the foregoing provisions of this subsection 4.9, and without
limiting the amending authority reserved to the Exchange by the provisions of
Section 5 of the Plan, the Exchange may amend this subsection 4.9 at any time
and in any respect, even as to amounts previously credited to a Participant's
Account, to the extent that the Exchange determines that

                                      -2-
<PAGE>

such amendment is necessary or desirable by reason of any change in tax laws or
regulations or interpretations thereof; provided, however, that no such
amendment shall apply with respect to amounts actually distributed under this
subsection 4.9 before the later of the date on which the amendment is adopted or
effective."

     IN WITNESS WHEREOF, the undersigned officer of the Exchange has caused
these presents to be executed on behalf of the Exchange this   day of December,
1998.

                                CHICAGO MERCANTILE EXCHANGE


                                By /s/ Craig S. Donohue
                                   ------------------------------------

                                  Its SVP & General Counsel
                                      ---------------------------------

                                      -3-
<PAGE>

                                                         Exhibit 10-
                                               Chicago Mercantile Exchange Inc.
                                              Registration Statement on Form S-4


                          CHICAGO MERCANTILE EXCHANGE
                    SUPPLEMENTAL EXECUTIVE RETIREMENT TRUST
                    ---------------------------------------
<PAGE>

                               TABLE OF CONTENTS
                               -----------------
<TABLE>
<CAPTION>
ARTICLE                                                                    PAGE
-------                                                                    ----
<S>  <C>                                                                   <C>
I    The Trust and the Plan ..............................................    2
          Establishment of Trust .........................................    2
          Irrevocability .................................................    2
          Name ...........................................................    2
          Plan ...........................................................    2
          Plan Administrator .............................................    2

II   Management and Control of Trust Fund Assets..........................    2
          The Trust Fund .................................................    2
          Trust Contributions ............................................    2
          Investment Guidelines ..........................................    2
          General Powers .................................................    3

III  Accounting and Distribution of Trust Assets..........................    4
          Statement of Account ...........................................    4
          Benefit Payments ...............................................    5
          Participant Subaccounts.........................................    5

IV   Compensation, Expenses and Liability ................................    6
          Compensation and Expenses ......................................    6
          Liability of Trustee ...........................................    6

V    Trust Fund Assets ...................................................    6
          Use of Trust Assets ............................................    6
          Claims of Creditors ............................................    6
          Claims of Participants .........................................    8
          Spendthrift Clause .............................................    8
          No Funding Requirement .........................................    8

VI   Tax Matters .........................................................    8
          Nature of Trust ................................................    8
          Federal and State Reporting Requirements .......................    8

VII  Miscellaneous .......................................................    9
          Disagreement as to Acts ........................................    9
          Persons Dealing With Trustee ...................................    9
          Evidence .......................................................    9
          Waiver of Notice ...............................................    9
          Counterparts ...................................................    9
          Governing Laws .................................................    9
          Successors, Etc. ...............................................    9
          Service of Legal Process .......................................    9

VIII Changes of Trustee...................................................   10
          Resignation ....................................................   10
          Removal of Trustee .............................................   10
</TABLE>

                                      -i-
<PAGE>

<TABLE>
<CAPTION>
ARTICLE                                                                    PAGE
-------                                                                    ----
<S>                                                                        <C>
          Duties of Resigned or Removed Trustee and of
               Successor Trustee .........................................   10

IX   Amendment and Termination ...........................................   10
          Amendment ......................................................   10
          Termination Upon Satisfaction of Plan Liabilities ..............   10
          Termination With Consent of Participants .......................   11
</TABLE>


                                     -ii-