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                                                                    EXHIBIT 10.3

                        ELECTRIC POWER SUPPLY AGREEMENT

                    Between Ameren Energy Marketing Company

                                      And

                    Central Illinois Public Service Company

THIS ELECTRIC POWER SUPPLY AGREEMENT (hereinafter "EPSA") made as of this 1st
day of May, 2000, by and between AMEREN ENERGY MARKETING COMPANY, (hereinafter
"Company") and CENTRAL ILLINOIS PUBLIC SERVICE COMPANY, d.b.a. AmerenCIPS
(hereinafter "Customer")  (Company and Customer may be identified collectively
as "Parties" or individually as a "Party") is for the supply by Company of all
electric power and energy needed to meet the Customer's full requirements for
electric power and energy.

WHEREAS, Company is engaged in the business of purchasing and reselling electric
power and energy; and

WHEREAS, Customer, which is a vertically-integrated electric public utility in
Illinois, is restructuring its operations in response to and in accordance with
the Illinois Electric Service Customer Choice and Rate Relief Law of 1997 (the
"Customer Choice Law") by transferring all of its existing generating facilities
to a newly-formed generation-company affiliate ("Ameren Energy Generating
Company" or "Genco"); and

WHEREAS, Company intends to enter into an agreement to purchase from Genco all
of the capacity and energy available from the generating units that are
transferred by Customer to Genco and any additional generating units that may be
acquired by Genco in the future; and

WHEREAS, Customer is required by the Customer Choice Law to continue to offer
bundled retail electric service within its existing retail electric service area
in Illinois at rates specified by the Illinois Commerce Commission ("ICC")
through December 31, 2004; and

WHEREAS, Customer may continue to make bundled sales of electricity to existing
wholesale electric service customers; and

WHEREAS, Customer is also obligated by the Customer Choice Law to offer retail
electric service to customers in Illinois under unbundled, market-priced tariffs
on file with the ICC and may also sell power to others at market-based rates
("Market Price Sales") through December 31, 2004; and

WHEREAS, Customer desires to acquire from Company all the electric power and
energy that is needed to enable it to provide electric service after the
transfer of its generating units; and

WHEREAS, Company is capable of supplying all such power and energy to Customer
and desires to do so pursuant to the rates, terms and conditions set forth
herein;

NOW THEREFORE, in consideration for the agreements and undertakings established
herein and the mutual benefits derived therefrom, it is agreed as follows:

1.  FIRM ELECTRIC POWER AND ENERGY SERVICE

Company will supply and deliver to Customer all of the firm electric capacity
and energy (hereinafter  "Energy") needed by Customer to serve its native load,
to operate its transmission and distribution system and to provide transmission
and distribution services, to fulfill its obligations under all applicable
federal and state tariffs or contracts, to satisfy regional reliability
requirements, and for any other purpose related to the provision of wholesale or
retail electric service and Customer shall purchase and pay for such Energy in
accordance with the terms of this Agreement.

2.  TERM

Subject to acceptance of this EPSA by the Federal Energy Regulatory Commission
("FERC"), supply and delivery of Energy pursuant to the EPSA shall begin on the
Transfer Date established in the "Asset Transfer Agreement" dated May 1, 2000
between Customer and Genco and terminate at 12:00 P.M. CPT on December 31, 2004.

3.  DELIVERY POINTS

All Energy supplied under this EPSA that is provided by generation sources
acquired by Genco from Customer shall be deemed to be delivered at the bus bar
connecting each such generation source to the Customer's transmission system.
All Energy supplied under this EPSA that is provided by other generation sources
shall be deemed to be delivered at the point of interconnection between
Customer's transmission system and the transmission system over which the Energy
is being delivered.  Energy supplied under this EPSA shall be sixty (60) hertz,
three (3) phase alternating current.

4.  TRANSMISSION

Transmission of Energy to Customer shall be firm transmission as such is defined
in the transmission provider's Open Access Transmission
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Tariff. Company shall be responsible for making all necessary transmission
arrangements for transmission of Energy to the Points of Delivery identified
above from sources not directly interconnected to the Ameren transmission
system, and for any communication with any transmission provider relating to the
transmission and delivery of Energy to Customer, including communications
concerning scheduling, tagging, displacements, disputes, or other operational
issues. Customer shall cooperate with Company for the purpose of attaining the
necessary firm transmission service and for implementing the transmission
service required for supplying the Energy to the Points of Delivery.

5.  METERING

The Parties recognize that certain meters used to measure the amount of Energy
received by Customer are owned by Customer.  In order that the accuracy of
registration is maintained in accordance with good utility practice, metering
equipment shall be tested by Customer at suitable intervals.  At the request of
Company, special tests shall be performed, but if less than two percent
inaccuracy is found, Company shall pay for the test.  The expense of all other
tests shall be borne by Customer.

Representatives of each Party may be present at all routine or special tests or
whenever any readings for the purposes of settlements are taken from meters not
having an automatic record.  If any test of metering equipment discloses an
inaccuracy exceeding two percent, the accounts of the Parties shall be adjusted
for the period, not exceeding 90 days, that such inaccuracy is estimated to have
existed.  Should any metering equipment fail to register, the amounts of Energy
delivered and demands established shall be estimated from the best available
data.  Meters shall be adjusted as nearly as practicable to 100.0% at the time
of any meter tests, and Customer shall furnish a copy of any meter test results
when requested by Company.

6.  SYSTEM PLANNING

In order for Company to plan adequately for Customer's Energy requirements,
Customer shall notify Company no later than November 1 of each year of its
annual load plan for the next calendar year during the Term.  Such annual load
plan shall be consistent with the forecasted peak demand reported to the Mid-
American Interconnected Network ("MAIN") for such year.  Customer shall also
provide to Company an update to its annual load plan on or before March 1 of
each year during the Term.

7.  RECORDS

Customer shall provide Company with all records that may reasonably be requested
by Company for the purpose of administering this EPSA.  The Parties shall keep
such records as may be needed to afford a clear history of all transactions
under this Agreement.  The originals of all such records shall be retained by
each party for a minimum of three years and copies shall be delivered to the
other Party upon request.

8.  PRICES

    A.  Charges For Energy Supplied To Customer For Sales Other Than Market
        -------------------------------------------------------------------
        Price Sales
        -----------

    1.  Capacity Charges
        ----------------

Each calendar year, Company will be entitled to be compensated at a rate of
$69,708/MW/Yr. for the quantity ("Quantity") of capacity supplied, which shall
be equal to the greater of:  (1) Customer's forecasted peak demand reported to
MAIN for that year, or (2) Customer's actual annual peak demand ("Peak Demand");
minus the portion of the forecasted or actual peak demand, as applicable,
represented by Market Price Sales.  For the purpose of this provision,
Customer's forecasted peak demand and actual annual peak demand shall be
adjusted for losses to the extent necessary to be determined at the Points of
Delivery.

For capacity supplied by Company during the year ending December 31, 2000, the
annual capacity charge shall be calculated by multiplying the Quantity by the
Rate, and then multiplying the result by a fraction, the numerator of which is
the number of days beginning with the Transfer Date and ending with December 31,
2000, and the denominator of which is 365.

Customer shall pay Company monthly for one-twelfth of the applicable annual
capacity charges for each calendar year during the Term (or a pro rata share of
such annual capacity charges during the year ending December 31, 2000) based on
Customer's forecasted peak demand for such year as reported to MAIN.  Within 10
days after the close of each calendar year, Company shall calculate the
Customer's capacity charges on the basis of Customer's actual annual peak
demand.  In the event that Customer's actual annual peak demand for such year
exceeded its forecasted peak demand that had been reported to MAIN for such
year, Customer shall pay Company for any additional capacity charges that are
due with respect to such year at the time of payment of its next monthly bill.

    2.  Energy Charges
        --------------

In addition to the capacity charges specified above, Customer shall pay Company
an energy charge of $21.81/Mwh for all energy supplied by Company to the Points
of Delivery for sale other than as Market Price Sales.

    B.  Charges For Energy Supplied To Customer For Market Price Sales
        --------------------------------------------------------------

In addition to the charges for Energy supplied to Customer as set forth above,
Customer shall pay Company an amount equal to the amount Customer receives from
retail customers for power and energy sold as Market Price Sales.  Within 15
days following the close of each calendar month, Customer shall advise Company
of the estimated amount of power and energy sold as Market Price Sales for such
month and the average rate per Mwh at which such power and energy was sold.
Payments for all Energy supplied to Customer for Market Price Sales shall be
remitted by Customer to Company in the month following the month in which
Customer receives payment for such Energy.  Within 45 days following the close
of each calendar month, Customer shall advise Company of the actual amounts of
Market Price Sales for such month, and the subsequent payments from Customer to
Company shall be adjusted accordingly.

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9.   REGULATION

The parties recognize that this EPSA is subject to regulation by the FERC
pursuant to Part II of the Federal Power Act.  If the FERC should require the
modification of this EPSA prior to its acceptance, the parties shall, in good
faith, attempt to reach agreement on modifications that would be acceptable to
the FERC in a manner that retains the economic benefits intended to be derived
by each party under this EPSA.

10.  ACCESS

Customer shall provide, at no cost to Company, a suitable place (including means
of support) on and access to Customer's property for Company to install,
maintain, operate, repair, replace, and remove all equipment and facilities
necessary for Company to perform its obligations under this EPSA.  Customer
shall use reasonable diligence to protect all of Company's equipment located on
Customer's property.

11.  PAYMENT OF BILLS

A. BILLING FOR SERVICE: Bills for Energy supplied to Customer for sales other
   than Market Price Sales will be based upon the Quantity of capacity and
   amount of energy supplied by Company at the Points of Delivery. Within 15
   days after the close of each calendar month, the Company will issue the bill
   to Customer electronically (commonly referred to as "EDI"), or other suitable
   means. If the Company is unable to obtain meter information or final Market
   Price Sales data is unavailable, an estimated bill will be issued, computed
   on the basis of Customer's previous use together with such other information
   as is available. Once all billing information is considered final, the
   estimated bill will be adjusted and any payment due difference will be
   reflected on the next scheduled billing.

B. PAYMENT PERIODS: The last date for payment of the "net amount" shown on the
   bill for Energy supplied to Customer for sales other than Market Price Sales
   shall be seven days after the date the bill is issued (hereinafter "Net
   Payment Period"). Payment of all amounts for all Energy supplied to Customer
   for Market Price Sales shall be due on the same date. In the event of a
   disputed bill Customer shall pay the undisputed portion within the Net
   Payment Period. When the last day of any Net Payment Period falls on a day
   other than a business day of Company, such period will be automatically
   extended to include the next following business day. Other than a business
   day of Company shall include Saturdays, Sundays, and the following holidays:
   New Year's day, Lincoln's Birthday, Washington's Birthday, Martin Luther
   King's Birthday, Good Friday, Memorial Day, Independence Day, Labor Day,
   Columbus Day, Veteran's Day, Thanksgiving day, Friday following Thanksgiving
   day, Christmas Eve (the last day of regular work schedule prior to Christmas
   day), Christmas day and New Year's Eve (the last day of regular work schedule
   prior to New Year's day). Whenever a holiday falls on Sunday the following
   Monday will not be considered a business day. Whenever a holiday falls on a
   Saturday, the prior Friday will not be considered a business day.

C. PAYMENT AND LATE PAYMENTS: Customer shall make payment to Company by wire
   transfer, or other acceptable means, within the Net Payment Period in
   immediately available U.S. funds. When a bill is paid after the last date for
   payment in the "net amount" shown on the bill a late payment charge
   equivalent to one and one half (1 1/2) percent will be assessed each month on
   the unpaid balance.

12.  INDEMNIFICATION

Customer shall indemnify and save harmless and defend Company from and against
any and all claims, demands, damages, costs or expenses arising, growing out of
or resulting in any manner after delivery of Energy to Customer or from improper
or negligent construction, installation, insulation, maintenance or operation of
Customer's lines and appurtenances.

13.  FORCE MAJEURE

In the event of Force Majeure, Company shall notify Customer immediately by oral
communication, confirmed in writing, of such occurrence, reporting the
commencement time and date, estimated duration, and estimated magnitude of the
reduction in Energy deliveries resulting from the Force Majeure situation.
Company shall not be liable for the failure to deliver Energy the full amount or
any part of the Energy to be supplied pursuant to this EPSA for the duration of
the Force Majeure. For the purpose of this provision, "Force Majeure" means an
event or circumstances which prevents Company from performing its obligations
under this EPSA, which is not within the reasonable control of the Company, and
which, by exercise of due diligence, the Company is unable to overcome or avoid
or cause to be avoided.  Force Majeure includes, but is not restricted to,
fires, strikes, labor stoppages, epidemics, floods, earthquakes, lightening
storms, ice, acts of God, riots, civil disturbances, civil war, invasion,
insurrection, military or usurped power, war, sabotage, explosions, failure of
equipment or of contractors or suppliers of materials or fuel, inability to
obtain or ship material, fuel or equipment because of the effect of similar
causes on suppliers or carriers, or an action or restraint by court order or
public or governmental authority (so long as the Company has not applied for or
assisted in the application for such court or governmental action).  Force
Majeure shall not include Company's ability to sell Energy to another purchaser
at a more advantageous price than that contained in this EPSA.  The settlement
of strikes, walkouts, lockouts, and other labor disputes shall be entirely
within the discretion of the Company, and Company may make settlement at such
time and on such terms and conditions as it may deem to be advisable.
Interruption by a transmission provider shall not be deemed to be an event of
Force Majeure unless (i) Company shall have made arrangements with such
transmission provider for the firm transmission, as defined under the
transmission provider's Open Access Transmission Tariff, of the Energy and (ii)
such interruption is due to "force majeure" or "uncontrollable force" or a
similar term as defined under the transmission provider's Open Access
Transmission Tariff, and (iii) no other path is available and no other remedy is
available.

14.  ASSIGNMENT

This EPSA shall inure to the benefit of, and be binding upon, the respective
successors and assigns of Customer and Company.  No assignment of this EPSA
shall be made by a Party except to a wholly owned subsidiary or successor to
substantially all of that Party's business who assumes possession and operates
substantially the same facilities and business as the assignor.
Notwithstanding the foregoing, either Party shall be free to assign this EPSA to
any of its subsidiaries or affiliates, without the written consent of the other
Party.  The assignment by a Party shall not relieve the Party, without the
written consent of the other Party, of any obligation to provide, or to accept
and pay for, as the case may be, the services contracted for hereunder.

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15.  NOTICES

All notices to be given under this EPSA shall be in writing via First Class U.S.
mail, FAX or e-mail and shall be deemed given when sent.  Notices shall be
addressed as set forth below, or to such other address as the party to be
notified may designate from time to time.

     Notice to Company:
     Jim Whitesides
     President
     Ameren Energy Marketing Company
     400 S. Fourth Street
     St. Louis, MO 63102

     Notice to Customer:

     Gary L. Rainwater
     President
     AmerenCIPS
     One Ameren Plaza
     1901 Chouteau Avenue
     St. Louis, MO 63103

16.  WRITTEN MODIFICATION

The rates for service specified herein shall remain in effect for all Energy
supplied by Company through December 31, 2004, and shall not be subject to
change through application to the FERC pursuant to the provisions of Section 205
of the Federal Power Act prior to that time absent the agreement of the Parties.
This EPSA shall not be modified except in writing by amendment, executed by both
parties, making express reference to the EPSA and the specific provisions hereof
modified or amended.

17.  LIMITS OF LIABILITY

IN THE EVENT OF LITIGATION UNDER THIS EPSA, THE PREVAILING PARTY SHALL BE
ENTITLED TO COMPENSATION FOR ANY REASONABLE ATTORNEYS FEES AND OTHER COSTS THAT
MAY BE INCURRED.  UNLESS EXPRESSLY HEREIN PROVIDED, NEITHER PARTY SHALL BE
LIABLE FOR ANY CONSEQUENTIAL, INCIDENTAL, PUNITIVE, EXEMPLARY OR INDIRECT
DAMAGES, LOST PROFITS OR OTHER BUSINESS INTERRUPTION DAMAGES, BY STATUTE, IN
TORT OR CONTRACT, UNDER ANY INDEMNITY PROVISION OR OTHERWISE.  IT IS THE INTENT
OF THE PARTIES THAT THE LIMITATIONS HEREIN IMPOSED ON REMEDIES AND THE MEASURE
OF DAMAGES BE WITHOUT REGARD TO THE CAUSE OR CAUSES RELATED THERETO, INCLUDING
THE NEGLIGENCE OF ANY PARTY, WHETHER SUCH NEGLIGENCE BE SOLE, JOINT OR
CONCURRENT, OR ACTIVE OR PASSIVE.

18.  DUTY TO MITIGATE

Each Party agrees that it has a duty to mitigate damages and covenants that it
will use commercially reasonable efforts to minimize any damages it may incur as
a result of the other Party's performance or non-performance of this EPSA.

19.  WAIVERS

Any waiver at any time by either Company or Customer of its rights with respect
to a default under this EPSA or with respect to any other matter arising in
connection with this EPSA shall not be deemed a waiver with respect to any
subsequent default or matter.  Any delay, short of the statutory period of
limitation, in asserting or enforcing any right under this EPSA shall not be
deemed a waiver of such right.

20.  ENTIRE AGREEMENT

This EPSA contains the entire agreement between the Parties in respect to the
subject matter contained herein, and there are no other understandings or
agreements between Company and Customer in respect thereof.

21.  WARRANTIES

The warranties expressly set forth in this EPSA are the sole warranties given by
either Party to the other Party in connection with the sale and purchase of
Energy hereunder.  EXCEPT AS SET FORTH HEREIN, COMPANY EXPRESSLY NEGATES ANY
OTHER REPRESENTATION OR WARRANTY, WRITTEN OR ORAL, EXPRESSED OR IMPLIED,
INCLUDING, WITHOUT LIMITATION, ANY REPRESENTATION OR WARRANTY WITH RESPECT TO
CONFORMITY TO MODELS OR EXAMPLES, OR MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.

22.  LIMITATION

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This EPSA is not intended to and shall not create rights of any character
whatsoever in favor of any person, corporation, association, or entity other
than the parties to this EPSA, and the obligations herein assumed are solely for
the use and benefit of the parties to this EPSA, their successors in interest,
or assigns.

23.  SURVIVORSHIP OF OBLIGATIONS

The termination of this EPSA shall not discharge any Party from any obligation
it owed to the other Party under the EPSA by reason of any transaction, loss,
cost, damage, expense or liability which shall occur or arise prior to such
termination.  It is the intent of the Parties that any such obligation owed
(whether the same shall be known or unknown as of the termination of this EPSA)
shall survive the termination of this EPSA.  The Parties also intend that the
indemnification and limitation of liability provisions contained in this EPSA
shall remain operative and in full force and effect, regardless of any
termination of this EPSA, except with respect to actions or events occurring or
arising after such termination is effective.

24.  GOVERNING LAW

The interpretation and performance of this EPSA shall be in accordance with and
controlled by the laws of the State of Illinois (including any applicable orders
and regulations issued by the ICC), except as to matters governed by federal
statute.

25.  SAVING CLAUSE

The provisions of this EPSA shall be interpreted where possible in a manner to
sustain their legality and enforcement.  If at any time a provision of this EPSA
is found to be unenforceable, such provision shall be removed and the rest of
this EPSA shall remain intact and in effect as if the removed provision was
never contained therein.

26.  RESOLUTION OF DISPUTES

If a question or controversy arises between the Parties concerning the
observance or performance of any of the terms, provisions or conditions
contained herein or the rights or obligations of either Party under this EPSA,
such question or controversy shall in the first instance be the subject of a
meeting between the Parties to negotiate a resolution of such dispute.  Such
meeting shall be held within fifteen (15) days of a request by either Party.  If
within fifteen (15) days after that meeting, the Parties have not negotiated a
resolution or mutually extended the period of negotiation, either Party may seek
resolution of the question or controversy by arbitration, subject, however, to
any prohibition thereto by any governmental law or regulation.

The Party calling for arbitration ("Initiating Party") shall give written notice
to the other Party setting forth (a) a short and plain statement of the issue(s)
to be arbitrated; (b) a short and plain statement of the claim showing that the
Initiating Party is entitled to relief; and (c) a statement of the relief to
which the Initiating Party claims to be entitled.  Such written notice including
sections (a), (b) and (c) defined above shall not exceed a document length of 20
pages, double spaced utilizing a font of 12.  Within twenty (20) days from the
date of receipt of such notice, the other Party ("Receiving Party") may submit
its written response and give notice in the same manner required above of
additional issues to be arbitrated.  The Initiating Party shall have twenty (20)
days to respond to any issues submitted for arbitration by the Receiving Party.

Within thirty (30) days of the date of the Initiating Party's written notice
requesting arbitration, each party shall designate a competent and disinterested
person to act as that party's designated arbitrator, with the two (2) persons
designated selecting a third neutral arbitrator within twenty (20) days of their
designation.  In the event the first two- (2) arbitrators cannot agree on a
mutually acceptable third arbitrator, they shall apply to the American
Arbitration Association ("AAA") to appoint the third arbitrator.  The
arbitration shall be conducted pursuant to the Federal Rules of Civil Procedure,
the Federal Rules of Evidence, and the Commercial Arbitration Rules of the AAA.

Any decision and award of the majority of arbitrators shall be binding upon both
parties.  The arbitrators shall not award any indirect, special, incidental or
consequential damages against either party.  Judgment upon the award rendered
may be entered in any court of competent jurisdiction.

27.  HEADINGS

The descriptive headings of the sections of this EPSA have been inserted for
convenience of reference only and shall not modify or restrict any of the terms
and provisions thereof.

IN WITNESS WHEREOF, the Parties hereto have caused this EPSA to be executed in
duplicate, by its authorized officers, day and year first above written.


AMEREN ENERGY MARKETING COMPANY          CENTRAL ILLINOIS PUBLIC SERVICE COMPANY


By /s/ James H. Whitesides               By /s/ Gary L. Rainwater
   ------------------------------------     ------------------------------------
(Company Officer Signature)              (Customer Officer Signature)


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  James H. Whitesides                      Gary L. Rainwater
---------------------------------------  ---------------------------------------
(Printed Name)                           (Printed Name)


  President                                President
---------------------------------------  ---------------------------------------
(Title)                                  (Title)

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