SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


In the Matter of:

AMEREN CORPORATION, et al.          SUPPLEMENTAL CERTIFICATE OF
                                    NOTIFICATION PURSUANT TO RULE 24 UNDER
                                    THE PUBLIC UTILITY HOLDING COMPANY ACT
                                    OF 1935


File No. 70-10078

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     Ameren Corporation  ("Ameren"),  a registered holding company, on behalf of
itself and its subsidiaries,  Ameren Energy Fuels and Services Company,  CILCORP
Inc.,  Central  Illinois  Light  Company  ("CILCO") and  AmerenEnergy  Resources
Generating  Company (f/k/a Central  Illinois  Generation,  Inc.) ("AERG") hereby
files this supplemental  certificate of notification  under Rule 24 reporting on
the  closing of a  transaction  as  required  by the  Commission  by order dated
January 29, 2003 (Holding Co. Act Release No. 27645).

     On October  3, 2003,  CILCO  transferred  its Duck Creek and E. D.  Edwards
coal-fired  plants  and  its  Sterling  Avenue  combustion   turbine  facilities
representing  approximately 1,100 megawatts of generating capacity,  all located
in Illinois, to its subsidiary, AERG, as a contribution in respect of all of the
outstanding stock of AERG and AERG's assumption of certain liabilities. Prior to
the  transfer,  the  transferred  assets were  released from the lien of CILCO's
Indenture of Mortgage and Deed of Trust which  secures  CILCO's  first  mortgage
bonds.  Also prior to the  transfer,  AERG filed  notification  with the Federal
Energy  Regulatory   Commission  that  it  relinquished  its  "exempt  wholesale
generator" or "EWG" status.

     The undersigned registered holding company has duly caused this certificate
to be signed on its behalf by the undersigned  officer thereunto duly authorized
pursuant to the requirements of the Public Utility Holding Company Act of 1935.

Ameren Corporation


By:  /s/ Steven R. Sullivan                        Date:  October 3, 2003
     ----------------------------
     Steven R. Sullivan
     Vice President Regulatory
     Policy, General Counsel and Secretary