SECURITIES AND EXCHANGE COMMISSION
                                 WASHINGTON, DC 20549



                                    FORM 8-K


                                 CURRENT REPORT




     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934



                Date of Report (Date of earliest event reported):
                                  July 2, 2001





                               AMEREN CORPORATION
             (Exact name of registrant as specified in its charter)




        Missouri                       1-14756                 43-1723446
(State or other jurisdiction         (Commission            (I.R.S. Employer
     of incorporation)               File Number)           Identification No.)




                 1901 Chouteau Avenue, St. Louis, Missouri 63103
              (Address of principal executive offices and Zip Code)






       Registrant's telephone number, including area code: (314) 621-3222


<PAGE>


ITEM 5.    OTHER EVENTS AND REGULATION FD DISCLOSURE

           Reference is made to "Rate Matters" in "Management's Discussion and
Analysis of Financial Condition and Results of Operations" on Page 20 and Note 2
(Missouri Electric) to the "Notes to Consolidated Financial Statements" on Page
31 of the Registrant's 2000 Annual Report to Stockholders pages incorporated by
reference in the Registrant's Form 10-K for the fiscal year ended December 31,
2000 (Year 2000 Form 10-K); to "Rates" under Item 1. Business of the
Registrant's Year 2000 Form 10-K; and to "Rate Matters" in "Management's
Discussion and Analysis of Financial Condition and Results of Operations" and to
Note 5 of the "Notes to Consolidated Financial Statements (Unaudited)" in the
Registrant's Form 10-Q for the quarterly period ended March 31, 2001, for a
discussion of matters relating to the expiration on June 30, 2001 of the
three-year experimental alternative regulation plan (the Plan) approved by the
Missouri Public Service Commission (MoPSC) for the Missouri retail electric
business of the Registrant's subsidiary, Union Electric Company (AmerenUE).

           With the Plan's expiration on June 30, 2001, on July 2, 2001, the
MoPSC staff filed with the MoPSC an excess earnings complaint against AmerenUE
that proposes to reduce AmerenUE's annual electric revenues ranging from $213
million to $250 million. Factors contributing to the MoPSC staff's
recommendation include return on equity (ROE), revenues and customer growth,
depreciation rates and other cost of service expenses. The ROE incorporated into
the MoPSC staff's recommendation ranges from 9.04% to 10.04%. Evidentiary
hearings on the MoPSC staff's recommendation must be conducted before the MoPSC.
The MoPSC is not bound by the MoPSC staff's recommendation. Depending on the
outcome of the Commission's decision, further appeals in the courts may be
warranted. As a result, a final decision on this matter may not occur until
2002. At this time, the Registrant can not predict the outcome of this complaint
proceeding, or its impact on the Registrant's financial position, results of
operations or liquidity; however, the impact could be material.

In the interim, the Registrant is preparing to vigorously attack the MoPSC
staff's recommendation in proceedings before the Commission. In addition, the
Registrant expects to continue negotiations with all pertinent parties with the
intent to continue with a form of incentive regulation similar to the Plan,
which expired on June 30, 2001. The Registrant can not predict the outcome of
these negotiations and their impact on the Registrant's financial position,
results of operations or liquidity.

Safe Harbor Statement

Statements made in this report, which are not based on historical facts, are
"forward-looking" and, accordingly, involve risks and uncertainties that could
cause actual results to differ materially from those discussed. Although such
"forward-looking" statements have been made in good faith and are based on
reasonable assumptions, there is no assurance that the expected results will be
achieved. These statements include (without limitation) statements as to future
expectations, beliefs, plans, strategies, objectives, events, conditions, and
financial performance. In connection with the "Safe Harbor" provisions of the
Private Securities Litigation Reform Act of 1995, the company is providing this
cautionary statement to identify important factors that could cause actual
results to differ materially from those anticipated. The following factors could
cause results to differ materially from management expectations as suggested by
such forward-looking statements: the effects of regulatory actions, including
changes in regulatory policy; and legal and administrative proceedings.



                                      -2-
<PAGE>



                                    SIGNATURE

           Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                                   AMEREN CORPORATION
                                                       (Registrant)


                                              By   /s/ Donald E. Brandt
                                            --------------------------------
                                                       Donald E. Brandt
                                                Senior Vice President, Finance
                                                 (Principal Financial Officer)


Date:  July 6, 2001
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SECURITIES AND EXCHANGE COMMISSION
                                 WASHINGTON, DC 20549

                                    FORM 8-K

                                 CURRENT REPORT

     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

                Date of Report (Date of earliest event reported):
                                  July 2, 2001

                               AMEREN CORPORATION
             (Exact name of registrant as specified in its charter)

        Missouri                       1-14756                 43-1723446
(State or other jurisdiction         (Commission            (I.R.S. Employer
     of incorporation)               File Number)           Identification No.)

                 1901 Chouteau Avenue, St. Louis, Missouri 63103
              (Address of principal executive offices and Zip Code)

       Registrant's telephone number, including area code: (314) 621-3222
ITEM 5.    OTHER EVENTS AND REGULATION FD DISCLOSURE

           Reference is made to "Rate Matters" in "Management's Discussion and
Analysis of Financial Condition and Results of Operations" on Page 20 and Note 2
(Missouri Electric) to the "Notes to Consolidated Financial Statements" on Page
31 of the Registrant's 2000 Annual Report to Stockholders pages incorporated by
reference in the Registrant's Form 10-K for the fiscal year ended December 31,
2000 (Year 2000 Form 10-K); to "Rates" under Item 1. Business of the
Registrant's Year 2000 Form 10-K; and to "Rate Matters" in "Management's
Discussion and Analysis of Financial Condition and Results of Operations" and to
Note 5 of the "Notes to Consolidated Financial Statements (Unaudited)" in the
Registrant's Form 10-Q for the quarterly period ended March 31, 2001, for a
discussion of matters relating to the expiration on June 30, 2001 of the
three-year experimental alternative regulation plan (the Plan) approved by the
Missouri Public Service Commission (MoPSC) for the Missouri retail electric
business of the Registrant's subsidiary, Union Electric Company (AmerenUE).

           With the Plan's expiration on June 30, 2001, on July 2, 2001, the
MoPSC staff filed with the MoPSC an excess earnings complaint against AmerenUE
that proposes to reduce AmerenUE's annual electric revenues ranging from $213
million to $250 million. Factors contributing to the MoPSC staff's
recommendation include return on equity (ROE), revenues and customer growth,
depreciation rates and other cost of service expenses. The ROE incorporated into
the MoPSC staff's recommendation ranges from 9.04% to 10.04%. Evidentiary
hearings on the MoPSC staff's recommendation must be conducted before the MoPSC.
The MoPSC is not bound by the MoPSC staff's recommendation. Depending on the
outcome of the Commission's decision, further appeals in the courts may be
warranted. As a result, a final decision on this matter may not occur until
2002. At this time, the Registrant can not predict the outcome of this complaint
proceeding, or its impact on the Registrant's financial position, results of
operations or liquidity; however, the impact could be material.

In the interim, the Registrant is preparing to vigorously attack the MoPSC
staff's recommendation in proceedings before the Commission. In addition, the
Registrant expects to continue negotiations with all pertinent parties with the
intent to continue with a form of incentive regulation similar to the Plan,
which expired on June 30, 2001. The Registrant can not predict the outcome of
these negotiations and their impact on the Registrant's financial position,
results of operations or liquidity.

Safe Harbor Statement

Statements made in this report, which are not based on historical facts, are
"forward-looking" and, accordingly, involve risks and uncertainties that could
cause actual results to differ materially from those discussed. Although such
"forward-looking" statements have been made in good faith and are based on
reasonable assumptions, there is no assurance that the expected results will be
achieved. These statements include (without limitation) statements as to future
expectations, beliefs, plans, strategies, objectives, events, conditions, and
financial performance. In connection with the "Safe Harbor" provisions of the
Private Securities Litigation Reform Act of 1995, the company is providing this
cautionary statement to identify important factors that could cause actual
results to differ materially from those anticipated. The following factors could
cause results to differ materially from management expectations as suggested by
such forward-looking statements: the effects of regulatory actions, including
changes in regulatory policy; and legal and administrative proceedings.

                                      -2-
SIGNATURE

           Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                                   AMEREN CORPORATION
                                                       (Registrant)

                                              By   /s/ Donald E. Brandt
                                            --------------------------------
                                                       Donald E. Brandt
                                                Senior Vice President, Finance
                                                 (Principal Financial Officer)

Date:  July 6, 2001