SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


--------------------------------------------------------------------------------
In the Matter of:

AMEREN CORPORATION                                QUARTERLY CERTIFICATE
AMEREN SERVICES COMPANY                           PURSUANT TO RULE 24 UNDER THE
UNION ELECTRIC COMPANY                            PUBLIC UTILITY HOLDING COMPANY
CENTRAL ILLINOIS PUBLIC SERVICE                   ACT OF 1935
COMPANY

File Nos. 70-9877, 70-9427, 70-9423 and 70-9133


================================================================================

     Ameren  Corporation  ("Ameren"),  a  registered  holding  company,  and its
subsidiaries  named  above,  hereby  file this  certificate  pursuant to Rule 24
reporting on  transactions  authorized by the Commission by orders dated October
5, 2001  (Holding  Co. Act Release No.  27449),  July 23, 1999  (Holding Co. Act
Release No. 27053), and March 22, 1999 (Holding Co. Act Release No. 26993). This
certificate is filed with respect to transactions consummated during the quarter
ended December 31, 2001.

A.   File No. 70-9877:
     ----------------

     1.   Sales of any Common Stock  (other than  pursuant to the Plans) and the
          purchase price per share and the market price per share at the date of
          the agreement of sale.

          N/A

     2.   The total number of shares of Common  Stock  issued or issuable  under
          options,  warrants or other  stock-purchase  rights granted during the
          quarter under the Plans.

          Dividend Reinvestment and Stock Purchase Plan        435,396
          Long Term Savings Plan 148                            11,787
          Long Term Savings Plan 702                             7,888
          Savings Investment Plan                              106,664
          Long Term Incentive Plan                                   0
                                                               -------

          Total                                                561,735

     3.   If Common Stock has been  transferred  to a seller of  securities of a
          company being acquired,  the number of shares so issued, the value per
          share and whether the shares are restricted to the acquiror.

          N/A

     4.   The amount and terms of any Long-term  Debt,  Preferred Stock or other
          preferred or equity-linked  securities  issued by Ameren,  directly or
          indirectly  through  a  Financing  Subsidiary,   during  the  calendar
          quarter.

          During the 4th quarter of 2001, Ameren Corporation issued $150 million
          floating   rate  notes  due  December   12,  2003.   These  notes  are
          non-callable and bear interest (reset quarterly) at 3-month LIBOR plus
          95 basis points.



     5.   The amount and terms of any  Short-term  Debt issued  directly or
          indirectly by Ameren during the calendar quarter.

          A.  Commercial paper issued through J. P. Morgan Securities, Bank
              of America Securities, and/or Goldman Sachs during the
              quarter, ranging from $290.4 million to $463.9 million, at an
              average interest rate of 2.3%.

          B.  Bank Loans from Banca Di Roma and Mellon Bank:
                     Banca Di Roma - $25,000,000 on 12/11/01 at a rate of 2.0%
                     Mellon Bank - $11,400,000 on 12/11/01 at a rate of 2.0%
                     Mellon Bank - $20,000,000 from 12/21/01 through 12/31/01 at
                     a rate of 2.15%

          Maximum indebtedness at any one time: $463.9 million on 11/21/01.

     6.   A description of the amount, terms and purpose of any Guarantee issued
          during the calendar  quarter by Ameren and the name of the beneficiary
          of such Guarantee.



          Parent          Subsidiary                    Amount             Terms          Purpose
                                                                            
          Ameren Corp.   Ameren Energy Marketing        $10,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Fuels & Svcs.    $ 1,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 3,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Fuels & Svcs.    $ 2,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 3,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Fuels & Svcs.    $ 1,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Communications   $ 1,920,000   10/26/01-12/31/03   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 3,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 3,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Fuels & Svcs.    $   500,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 1,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 4,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Fuels & Svcs.    $   500,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $ 7,000,000   12/20/01-12/31/02   Credit Support
          Ameren Corp.   Ameren Energy Marketing        $10,000,000   12/18/01-12/31/02   Credit Support



     7.   The name and amount  invested  by Ameren in any  Financing  Subsidiary
          during the calendar quarter.

          N/A

     8.   The notional  amount and principal terms of any Interest Rate Hedge or
          Anticipatory Hedge entered into during the quarter and the identity of
          the parties to such instruments.

          No such agreements were entered into during the 4th quarter of 2001.

     9.   Consolidated  balance  sheet of Ameren  as of the end of the  calendar
          quarter.

          Incorporated  by reference to current report on Form 8K dated 02-14-02
          in File No. 1-14756.

B.   File No. 70-9427:
     ----------------

     1.   Balance Sheet and Income  Statement for each  Intermediate  Subsidiary
          for the three, six or nine month period ended.

          N/A

                                       2


     2.   Information  concerning the nature and extent of services  provided by
          Ameren  Development,  Ameren  Energy,  CIC  or any  other  non-utility
          subsidiary that is authorized or permitted under the Act to sell goods
          and services during the quarter,  identifying the associate company to
          which such services are sold, the service and the charge,  and stating
          whether the charge was computed at cost,  market or by another  method
          (as specified herein).

          To be filed confidentially under Rule 104.

     3.   Information   concerning  the  completion  of  any  reorganization  of
          Ameren's  ownership in  Intermediate  Subsidiaries  and/or  Nonutility
          Subsidiaries,  including  the identity of the  companies  involved and
          their line of business and corporate  structure  both before and after
          the reorganization.

          N/A

C.   File No. 70-9423:
     ----------------

     The maximum  outstanding  amount of all borrowings  under or investments in
     the Utility  Money Pool by each Utility Money Pool  participant  during the
     quarter,  and the rate or range of rates  charged  on  Utility  Money  Pool
     borrowings and paid on Utility Money Pool investments during the quarter.

     Maximum contribution/investment for CIPS -                   $24.2 million
     Maximum contribution/investment for Union Electric   -      $116.3 million
     Maximum contribution/investment for Ameren Corporation -     $50.0 million

     Maximum borrowing for Ameren Services -                     $108.0 million
     Maximum borrowing for CIPS -                                 $49.4 million

     Average interest rate for the Utility Money Pool for the quarter:  2.3%

D.   File No. 70-9133:
     ----------------

     1.   The amount and terms of any  Short-term  Debt issued by Union Electric
          or CIPS  (other  than  through  the  Utility  Money  Pool)  during the
          calendar quarter.

          Union  Electric:
          Commercial  paper  issued  through Bank One Capital  Markets,  Goldman
          Sachs,  and/or A. G. Edwards & Sons,  ranging from a low of $0.00 to a
          high of $196.3 million, at an average interest rate of 2.3%.

     2.   The notional  amount and  principal  terms of any Interest  Rate Hedge
          entered  into  during the  quarter by Union  Electric  or CIPS and the
          identity of the parties to such instruments.

          No such agreements were entered into during the 4th quarter of
          2001.


                                       3




                                    SIGNATURE

     The undersigned  registered  holding company has duly caused this quarterly
report 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
                                             --------------------------------
                                                  Steven R. Sullivan
                                             Vice President, General Counsel
                                                       and Secretary
February 28, 2002






                                       4