Time:     9:00 A.M.
                April 24, 2001

      Place:    Powell Symphony Hall
                718 North Grand Boulevard
                St. Louis, Missouri


      Admission to the meeting  will be by ticket  only.  If you plan to attend,
please  advise the Company in your proxy vote (by  telephone  or by checking the
appropriate box on the proxy card).  Persons without tickets will be admitted to
the meeting upon verification of their stockholdings in the Company.

      Please vote by proxy (via  telephone or the  enclosed  proxy card) even if
you own only a few  shares.  If you attend the  meeting  and want to change your
proxy vote, you can do so by voting in person at the meeting.



To the Stockholders of


      We will hold the Annual Meeting of Stockholders  of Ameren  Corporation at
Powell  Symphony  Hall,  718 North Grand  Boulevard,  St.  Louis,  Missouri,  on
Tuesday, April 24, 2001, at 9:00 A.M., for the purposes of

      (1)electing Directors of the Company for terms ending in April 2002;

      (2)considering a stockholder proposal relating to releases from the
         Callaway Plant; and

      (3)acting on other proper business presented to the meeting.

      The Board of Directors of the Company presently knows of no other business
to come before the meeting.

      If you owned shares of the Company's Common Stock at the close of business
on March 8, 2001, you are entitled to vote at the meeting and at any adjournment
thereof. All shareowners are requested to be present at the meeting in person or
by proxy so that a quorum may be assured.

      You may vote via telephone or, if you prefer,  you may sign and return the
enclosed  proxy card in the  enclosed  envelope.  Your prompt vote by proxy will
reduce  expenses.  Instructions  for voting by telephone  are included with this
mailing.  If you attend  the  meeting,  you may  revoke  your proxy by voting in

By order of the Chairman and the Board of Directors.

                                    STEVEN R. SULLIVAN

St. Louis, Missouri
March 15, 2001

(First sent or given to stockholders March 15, 2001)

Principal Executive Offices:
One Ameren Plaza
1901 Chouteau Avenue, St. Louis, MO 63103

      This  solicitation  of proxies is made by the Board of Directors of Ameren
Corporation  (the "Company" or "Ameren") for the Annual Meeting of  Stockholders
of the Company to be held on Tuesday,  April 24,  2001,  and at any  adjournment

      As a result of a merger  effective  December 31, 1997 (the "Merger"),  the
Company is a holding company, the principal first tier subsidiaries of which are
Union Electric  Company,  d/b/a AmerenUE  ("Union  Electric"),  Central Illinois
Public Service  Company,  d/b/a  AmerenCIPS  ("CIPS"),  Ameren Services  Company
("Ameren Services"),  AmerenEnergy  Resources Company ("AER"), and AmerenEnergy,


Who Can Vote

      The  accompanying  proxy  card  represents  all shares  registered  in the
name(s)  shown  thereon,   including   shares  in  the  Company's  DRPlus  Plan.
Participants in the Ameren  Corporation  Savings  Investment  Plans will receive
separate proxies for shares in such plans.

      Only  stockholders  of record at the close of business on the Record Date,
March 8, 2001, are entitled to vote at the meeting. The voting securities of the
Company on such date consisted of 137,215,462  shares of Common Stock.  In order
to conduct the meeting,  holders of more than one-half of the outstanding shares
must be present in person or represented by proxy so that there is a quorum.  It
is important  that you vote promptly so that your shares are counted  toward the

      In  determining  whether  a  quorum  is  present  at the  meeting,  shares
registered  in the name of a broker  or other  nominee,  which  are voted on any
matter,  will be  included.  In  tabulating  the number of votes cast,  withheld
votes, abstentions, and non-votes by banks and brokers are not included.

      The Board of  Directors  has  adopted a  confidential  voting  policy  for

How You Can Vote

      By Proxy.  Before the  meeting,  you can give a proxy to vote your shares
                 of the  Company's  Common  Stock in one of the following ways:

-        by calling the toll-free telephone number; or

-        by  completing  and signing  the  enclosed  proxy card and  mailing it
         in time to be  received  before the meeting.

      The telephone voting procedure is designed to confirm your identity and to
allow you to give your voting  instructions.  If you wish to vote by  telephone,
please follow the enclosed instructions.

      If you mail us your  properly  completed and signed proxy card, or vote by
telephone,  your shares of the Company's Common Stock will be voted according to
the  choices  that you  specify.  If you sign and mail your proxy  card  without
marking any choices,  your proxy will be voted as recommended by the Board - FOR
the Board's nominees for Director and AGAINST Item 2. On any other matters,  the
named proxies will use their discretion.

      In Person.  You may come to the  meeting  and cast your vote  there.  Only
stockholders  of record at the close of  business on the Record  Date,  March 8,
2001, are entitled to vote at the meeting.

How You Can Revoke Your Proxy

      You may  revoke  your proxy at any time after you give it and before it is
voted by  delivering  either a written  revocation  or a signed proxy  bearing a
later  date to the  Secretary  of the  Company  or by  voting  in  person at the

                             ITEMS TO BE CONSIDERED

Item (1):  Election of Directors

      Fourteen  directors  are to be elected at the meeting,  to serve until the
next annual meeting of stockholders  and until their  successors are elected and
qualified.  The nominees  designated  by the Board of Directors are listed below
with information about their principal occupations and backgrounds.



Retired Chairman of the Board of Directors and Chief Executive Officer of Union
Electric.  Mr. Cornelius joined Union Electric in 1962, held several management
positions, and became President in 1980. In 1988 he was elected Chairman of the
Board and served in that capacity until his retirement in 1994. He is a member
of the Executive and Contributions Committees of the Board of Directors.
Director of the Company since 1997. Other directorships:
GenAmerica Financial Corporation.  Age: 69.


Retired Vice Chairman of the Company and retired  President and Chief  Executive
Officer of CIPSCO  Incorporated and CIPS. Mr. Greenwalt joined CIPS in 1963, was
elected a senior vice  president  in 1980,  and was named  President  and CEO in
1989. Mr. Greenwalt is a member of the Executive and Contributions Committees of
the Board. Director of the Company since 1997. Age: 68.


Retired  Deputy  Chairman of The May  Department  Stores  Company,  a nationwide
retailing organization.  Mr. Hays joined the May organization in 1969. He served
as Vice  Chairman  from 1982 to 1985 and  President  from 1985 to 1993,  when he
became Deputy  Chairman.  He is a member of the  Executive  and Human  Resources
Committees   of  the  Board.   Director  of  the  Company   since  1997.   Other
directorships: Leggett & Platt Incorporated; Payless Shoe Source, Inc. Age: 68.


Former Chairman of the Board, Firstar  Corporation,  a bank holding company. Mr.
Jacobsen was elected Chief Executive Officer of Mercantile  Bancorporation Inc.,
a bank holding company,  in 1989 and became Chairman of Firstar Corporation upon
Mercantile's  merger with Firstar in 1999. He was elected to  directorship  with
U.S.  Bancorporation  upon its  merger  with  Firstar  in 2001.  Adviser  to the
Company's  Board since 1997. A first-time  nominee as Director of the  Company's
Board. Other  directorships:  U.S.  Bancorporation;  Federal Reserve Bank of St.
Louis; Trans World Airlines. Age: 61.



Chairman of GenAmerica  Financial  Corporation,  which  provides  life,  health,
pension,  annuity and related insurance products and services.  Mr. Liddy joined
GenAmerica as President and Chief  Operating  Officer in 1988 and was elected to
his present position in 1995. Mr. Liddy is a member of the Auditing Committee of
the Board.  Director of the Company since 1997. Other directorships:  Brown Shoe
Company,  Inc.; Ralston Purina Company;  Energizer Holdings,  Inc.;  Reinsurance
Group of America. Age: 65.


Retired Chairman and Chief Executive Officer of AMSTED Industries  Incorporated,
Chicago,  Illinois,  a  manufacturer  of  railroad,  construction,  and  general
industrial  products.  Mr. Lohman was elected  President of AMSTED Industries in
1988 and became Chief Executive Officer in 1990 and Chairman in 1997. Mr. Lohman
is a member of the  Executive  and Human  Resources  Committees  of the Board of
Directors.  Director of the Company  since 1997.  Other  directorships:  Fortune
Brands, Inc. Age: 66.


Chairman,  President  and  Chief  Executive  Officer  of  Illinois  Consolidated
Telephone Company,  Mattoon,  Illinois,  Vice Chairman of McLeodUSA Incorporated
and Chairman of Illuminet  Holdings,  Inc. Mr. Lumpkin was elected  Treasurer of
Illinois  Consolidated  Telephone  Company in 1968,  President in 1977,  and was
named to his present  position in 1990. As a result of a September  1997 merger,
he also serves as Vice  Chairman of  McLeodUSA.  He is a member of the  Auditing
Committee of the Board. Director of the Company since 1997. Other directorships:
McLeodUSA; First Mid-Illinois Bancshares, Inc.; First Mid-Illinois Bank & Trust;
Illuminet Holdings, Inc. Age: 66.


Retired Chairman and Chief Executive  Officer of Boatmen's Trust Company,  which
conducted a general trust  business.  Prior to being elected to such position in
1988, he served as President and Chief Executive  Officer of Centerre Bank, N.A.
He is Chairman of the Human Resources and Nominating Committees of the Board and
is a member of the  Executive  Committee.  Director of the  Company  since 1997.
Other directorships: Brown Shoe Company, Inc. Age: 67.



Principal  in Hanne  Merriman  Associates,  Washington,  D.C.,  retail  business
consultants.  Ms.  Merriman  is a member  of the  Contributions  and  Nominating
Committees   of  the  Board.   Director  of  the  Company   since  1997.   Other
directorships: Ann Taylor Stores Corporation; US Airways Group, Inc.; State Farm
Mutual Automobile  Insurance Co.; The Rouse Company; T. Rowe Price Mutual Funds;
Finlay Enterprises, Inc. Age: 59.


President and Chief Executive Officer of P. L. Miller & Associates, a management
consultant  firm which  specializes  in  strategic  and  financial  planning for
privately held companies and distressed businesses and in international business
development.  He is also a principal in a financial  advisory  firm for small to
middle market companies.  Mr. Miller has served as president of an international
subsidiary of an investment banking firm, and for over 20 years was president of
consumer product  manufacturing  and  distribution  firms. He is a member of the
Auditing Committee of the Board. Director of the Company since 1997. Age: 58.


Chairman, President and Chief Executive Officer of the Company and President and
Chief Executive Officer of Union Electric and Ameren Services. Mr. Mueller began
his career with Union Electric in 1961 as an engineer. He was named Treasurer in
1978,  Vice  President-Finance  in 1983,  Senior  Vice  President-Administrative
Services in 1988;  President in 1993 and Chief  Executive  Officer in 1994.  Mr.
Mueller was elected  Chairman of Ameren and Ameren Services upon the Merger.  He
is a member of the Executive and Contributions Committees of the Board. Director
of the Company since 1997. Mr.  Mueller is Chairman of the Federal  Reserve Bank
of St. Louis.  Other  directorships:  Union Electric  (since 1993);  CIPS (since
1997); Angelica Corporation. Age: 62.


Partner of Cynwyd Investments,  a family real estate  partnership.  Mr. Saligman
also served in various  executive  capacities in the consumer  products industry
for more than 25 years.  He is Chairman of the Auditing  Committee of the Board.
Director of the Company since 1997. Age: 62.



Chairman of Janet McAfee  Inc.,  a  residential  real estate  company  which she
founded in 1975.  She is a member of the  Auditing,  Executive,  and  Nominating
Committees and is Chairman of the Contributions Committee of the Board. Director
of the Company since 1997. Age: 71.


Retired Vice Chairman of Caterpillar,  Inc. Mr.  Wogsland was elected  Executive
Vice  President and director of  Caterpillar in 1987. He served as Vice Chairman
and director from 1990 until his retirement in 1995. Mr. Wogsland is a member of
the Auditing  Committee of the Board.  Director of the Company since 1997.  Age:
      The  fourteen  nominees  for  Director  who receive the most votes will be

      The Board of Directors knows of no reason why any nominee will not be able
to serve as a Director.  If, at the time of the Annual  Meeting,  any nominee is
unable or declines to serve,  the proxies may be voted for a substitute  nominee
approved by the Board.

      During 2000, the Board of Directors met six times. Except for Mr. Jacobsen
who is a first-time nominee,  all nominees attended at least 78% of the meetings
of the Board and the Board Committees of which they were members,  and aggregate
attendance of the nominees as a group exceeded 93%.

      Age  Policy -  Directors  who attain age 72 prior to the date of an annual
meeting cannot be designated as a nominee for election at such meeting. Director
Robert H. Quenon is completing his Board service at the Annual Meeting  pursuant
to this age policy. In addition, the eligibility of former employees, except for
one who has been elected Chief  Executive  Officer of Ameren,  Union Electric or
CIPS, is limited to the date upon which they retire,  resign or otherwise  sever
active employment with the respective company.

      Board  Committees  -  The  Board  of  Directors  has  standing   Auditing,
Contributions, Executive, Human Resources and Nominating Committees, the members
of which are identified in the biographies above. The Auditing,  Human Resources
and Nominating  Committees are comprised entirely of outside directors.  Each of
the members of the Auditing  Committee is independent as defined by the New York
Stock Exchange listing standards.


      The general functions of the Auditing  Committee  include:  (1) reviewing,
with management and the independent  accountants,  the adequacy of the Company's
system of internal accounting  controls;  (2) reviewing the scope and results of
the  annual   examination  and  other  services  performed  by  the  independent
accountants; (3) reviewing, with management and the independent accountants, the
Company's annual audited financial  statements and recommending to the Board the
inclusion of such  financial  statements in the  Company's  Annual Report on SEC
Form  10-K;  (4)  recommending  to the  Board  the  appointment  of  independent
accountants and approving fees for the services they perform;  and (5) reviewing
the  scope  of  audits  and  annual  budget  of  the  Company's  internal  audit
department.  The  Board of  Directors  has  adopted a  written  charter  for the
Auditing  Committee,  which is included as an appendix to this proxy  statement.
The Auditing Committee held three meetings in 2000.

      The  Contributions  Committee  makes  policies  and  recommendations  with
respect to charitable and other contributions.  The Contributions Committee held
three meetings in 2000.

      The  Executive  Committee  has such duties as may be  delegated to it from
time to time by the Board. The Executive Committee did not meet in 2000.

      The Human Resources  Committee  considers the  qualifications of executive
personnel  and  recommends  changes  therein,  considers  or  recommends  salary
adjustments  for certain  employees and  considers and acts on important  policy
matters affecting  Company  personnel.  The Human Resources  Committee held four
meetings in 2000.

      The  Nominating  Committee  considers and  recommends  for Board  approval
candidates  for the Board of Directors,  as  recommended  by  management,  other
members of the Board,  stockholders and other interested parties. The Nominating
Committee held one meeting in 2000.

      Directors'  Compensation  - Directors  who are employees of the Company do
not receive compensation for their services as a Director.

      Each  Director  who is not an employee  of the Company  receives an annual
retainer of $20,000, an annual award of 400 shares of the Company's Common Stock
and a fee of $1,000 for each Board  meeting  and each  Board  Committee  meeting

      An optional  deferred  compensation  plan  available to Directors  permits
non-employee Directors to defer all or part of their annual


retainer and meeting fees.  Deferred  amounts,  plus an interest  factor,  are
used to provide payout distributions  following completion of Board service and
certain death benefits. Costs of the deferred compensation plan are expected to
be recovered through the purchase of life insurance on the participants, with
the Company being the owner and beneficiary of the insurance policies.

Item (2):  Stockholder Proposal Relating to Releases from the Callaway Plant

   Proponents  of the  stockholder  proposal  described  below  notified  the
Company of their  intention  to attend the 2001  Annual  Meeting to present  the
proposal for consideration and action. The names and addresses of the proponents
and the number of shares they hold will be  furnished  by the  Secretary  of the
Company upon receipt of any oral or written request for such information.

WHEREAS:  Nuclear power plants,  including  Callaway,  during routine operation,
release into the air and water radioactive  wastes which we believe increase the
risk of life-shortening illnesses, genetic mutations, and environmental damage;
Though the federal government's  "permissible" concentration levels govern these
      releases,  we  believe  "permissible"  does  not  mean  safe,  but  merely
AmerenUE extracts Missouri River water for Callaway's cooling systems,  and some
      of that water becomes radioactively contaminated;
Some  wastewater streams  contaminated with concentrations of radioactivity that
      exceed  permissible  federal release standards are placed in storage tanks
      until  some of the  shorter-lived  isotopes  can  decay;  some  wastewater
      streams are  re-filtered  before being recycled  (within the plant) or are
      released to the river;  some  wastewater  streams  are merely  pumped into
      other waste  processing  tanks to be diluted  with  cleaner  water  before
      discharge  to the river.  Instruments  monitoring  the flow of  wastewater
      batches after  discharge are set only to detect  gamma-emitting  isotopes;
      some beta emitters  (including tritium and noble gases) and alpha emitters
      can be  released  without  detection.  Unfiltered,  accidental  leaks  and
      releases can also occur through the established liquid effluent pathways;
One   contaminant - tritium, a radioactive  isotope of hydrogen - accumulates in
      the cooling water as a fission and activation product;
Since no economically  feasible technology exists to filter tritium from cooling
      water effluents, it is released in gaseous emissions to the atmosphere and
      in liquid  releases into the Missouri  River - 79 miles  upstream from St.
      Louis County's drinking water intake;

The medical profession typically decontaminates a lab table for spills of even
      90  trillionths  (per  four-inch  square)  of one curie of  radioactivity.
      During  Callaway's  operation  in 1999,  the  Company  reported  releasing
      1,480.8  curies  of  tritium  in  267  batches  of  filtered   radioactive
      wastewater  into the Missouri River.  The company also reported  releasing
      tritium to the atmosphere;
Tritium  can be  ingested  or  inhaled,  potentially  causing  reproductive,
      cellular,  and  genetic  damage.  Its
      half-life is 12.3 years;
Because tritium  and the other  radioactive  isotopes  routinely  released  from
      Callaway will continue emitting radiation  particles and rays for at least
      ten  half-lives,  the impacts of the Callaway  liquid wastes on the water,
      algae, fish and other creatures  (including humans) living downwind can be

RESOLVED:  shareholders request that Ameren describe, in its next annual report,
its efforts to reduce the release of radioactive  materials to the air and water
during Callaway's routine operation.


Radioactive releases occur during Callaway's routine operation.  We believe that
the  impact of these  planned  radiation  releases,  no  matter  how  small,  is
cumulative,  irreversible, and potentially dangerous. In addition, the threat of
disastrous accidental releases remains.  Ameren should take responsibility for a
more complete accounting of all radiation releases,  so that the Company and its
shareholders can more accurately assess the plant's impact on the biosphere.


      On-going  measurements at Callaway  consistently  show that plant effluent
releases are less than ten percent of the levels allowed by current regulations.
This  low  level  of  effluent  releases  clearly   demonstrates  the  Company's
successful  commitment to reduce the level of radioactive material released from
the Callaway Plant.  Because  effluent  releases at Callaway are already a small
fraction of allowable  standards,  additional  reporting or  expenditures by the
Company would have minimal  impact,  and the Board  therefore  recommends a vote

      Passage of the proposal requires the affirmative vote of a majority of the
votes cast.


Item (3):  Other Matters

      The  Board  of  Directors  does  not know of any  matter,  other  than the
election of Directors  and the proposal set forth above,  which may be presented
to the meeting.

                               SECURITY OWNERSHIP

      Based on an  Amendment  to  Schedule  13G filed  with the  Securities  and
Exchange  Commission  on February 12,  2001,  Capital  Research  and  Management
Company,  333  South  Hope  Street,  Los  Angeles,  California  90071,  had sole
dispositive  power over  7,137,800  shares of the Company's  Common Stock and no
voting  power with  respect to any such  shares.  Pursuant to Rule  13d-4,  such
Company  disclaimed  beneficial  ownership of the reported shares.  The reported
shares  represent  approximately  5.2% of the  outstanding  Common  Stock of the


                                                     Shares of Common Stock
                                                         of the Company
                                                     Beneficially Owned
                   Name                              as of February 1, 2001
       Paul A. Agathen                                          32,980
       Donald E. Brandt                                         33,222
       William E. Cornelius                                     12,236
       Clifford L. Greenwalt                                    17,083
       Thomas A. Hays                                           10,355
       Thomas H. Jacobsen                                        7,282
       Richard A. Liddy                                          3,852
       Gordon R. Lohman                                          1,742
       Richard A. Lumpkin                                        3,955
       John Peters MacCarthy                                    10,255
       Hanne M. Merriman                                         3,784
       Paul L. Miller, Jr.                                       3,367
       Charles W. Mueller                                       95,541
       Robert H. Quenon                                      4,337
       Gary L. Rainwater                                        19,451
       Garry L. Randolph                                        14,659
       Harvey Saligman                                           4,255
       Janet McAfee Weakley                                      4,875
       James W. Wogsland                                         2,566

       All Directors, nominees for Director
       and executive officers as a group                   489,884


      Includes shares held jointly. Also includes shares issuable within 60
          days upon the  exercise  of stock  options as  follows:  Mr.  Agathen,
          28,175;  Mr. Brandt,  31,675;  Mr.  Mueller,  84,950;  Mr.  Rainwater,
          13,425;  and Mr. Randolph,  12,250.  Reported shares include those for
          which a Director, nominee for Director or executive officer has voting
          or  investment  power  because of joint or fiduciary  ownership of the
          shares or a  relationship  with the  record  owner,  most  commonly  a
          spouse,  even if such  nominee  or  executive  officer  does not claim
          beneficial ownership.

      Shares beneficially owned by all Directors, nominees for Director and
           executive  officers in the aggregate do not exceed one percent of any
           class of equity securities outstanding.

      Director Quenon is completing his Board service at the Annual Meeting.

      There are no family  relationships  between any  Director,  executive
           officer,  or person  nominated  or chosen by the  Company to become a
           Director or executive  officer  except that Charles W. Mueller is the
           father of  Michael G.  Mueller,  who is a Vice  President  of certain
           Company subsidiaries.

                             EXECUTIVE COMPENSATION

Ameren Corporation Human Resources Committee Report on Executive Compensation

      Ameren  Corporation  and its  subsidiaries'  (collectively  referred to as
"Ameren") goal for executive  compensation  is to approximate  the median of the
range  of  compensation  paid  by  similar  companies.  Accordingly,  the  Human
Resources  Committee of the Board of Directors of Ameren  Corporation,  which is
comprised  entirely  of  non-employee  Directors,  makes  annual  reviews of the
compensation  paid  to  the  executive   officers  of  Ameren.  The  Committee's
compensation  decisions with respect to the five highest paid officers of Ameren
Corporation  and its  principal  subsidiaries  are  subject to  approval by such
company's  Board of  Directors.  Following  the annual  reviews,  the  Committee
authorizes  appropriate  changes as determined by the three basic  components of
the executive compensation program, which are:

o        Base salary,

o        A performance-based short-term incentive plan, and

o        Long-term stock-based awards.

      First,  in evaluating  and setting base  salaries for executive  officers,
including  the  Chief   Executive   Officers  of  Ameren   Corporation  and  its
subsidiaries,  the Committee considers:  individual responsibilities,  including
changes which may have occurred since the prior review;


individual  performance in  fulfilling   responsibilities,   including  the
degree  of  competence  and initiative exhibited;  relative contribution to the
results of operations;  the impact of  operating  conditions;  the  effect  of
economic  changes  on salary structure;  and comparisons with compensation paid
by similar companies. Such considerations are subjective, and specific measures
are not used in the review process.

      The  second  component  of  the  executive   compensation   program  is  a
performance-based  Executive  Incentive  Compensation  Plan  established  by the
Ameren Corporation Board, which provides specific,  direct relationships between
corporate results and Plan compensation.  For 2000, Ameren consolidated year-end
earnings  per  share  (EPS)  target  levels  were  set  by the  Human  Resources
Committee.  If EPS  reaches at least the minimum  target  level,  the  Committee
authorizes  incentive  payments  within  prescribed  ranges based on  individual
performance  and  degree of  responsibility.  If EPS fails to reach the  minimum
target level, no payments are made. Under the Plan, it is expected that payments
to the Chief Executive  Officers of Ameren Corporation and its subsidiaries will
range from 0-37% of base salary.  For 2000, actual payments ranged from 28.8% to
35.6% of base salary.

      The third  component  of the 2000  executive  compensation  program is the
Long-Term  Incentive Plan of 1998, which also ties  compensation to performance.
The Plan was  approved  by Ameren  Corporation  shareholders  at its 1998 Annual
Meeting and provides  for the grant of options,  restricted  stock,  performance
awards,  stock  appreciation  rights  and  other  awards.  The  Human  Resources
Committee  determines who  participates  in the Plan and the number and types of
awards to be made. It also sets the terms, conditions,  performance requirements
and limitations  applicable to each award under the Plan.  Awards under the 1998
Plan have  been at levels  that  approximate  the  median of the range of awards
granted by similar companies.

      In  determining  the reported  2000  compensation  of the Chief  Executive
Officers,  as well as compensation for the other executive  officers,  the Human
Resources Committee considered and applied the factors discussed above. Further,
the reported  compensation  reflects an  above-average  level of  achievement in
attaining 2000 EPS. Authorized compensation for the Company's executive officers
fell within the ranges of those paid by similar companies.

                       /s/ John Peters MacCarthy, Chairman
                                      /s/ Thomas A. Hays
                                      /s/ Gordon R. Lohman
                                      /s/ Robert H. Quenon


Compensation Tables

      The following  tables contain  compensation  information,  for the periods
indicated,  for (a) the Chairman,  President and Chief Executive  Officer of the
Company and (b) the four other most highly compensated executive officers of the
Company who were serving as executive officers at the end of 2000.

                           SUMMARY COMPENSATION TABLE

                                     Annual            Securities     All Other
          Name and                 Compensation        Underlying     Compen-
Principal Position  Year  Salary($)   Bonus($)    Options(#)     sation($)
---------------------   ---- ---------   --------     ----------     ---------

C. W. Mueller           2000  660,000    235,200      108,100      79,421 
Chairman of Ameren;     1999  580,000    206,000       75,300      45,850
President and Chief     1998  550,000    198,000       63,800      53,751
Executive Officer,
Ameren, Union Electric
and Ameren Services

G. L. Rainwater         2000   400,000    115,200       32,600       9,450 
President and Chief     1999   342,000     97,500       27,900       4,825
Executive Officer,CIPS; 1998   325,000     93,000       25,800          66
President, AER

D. E. Brandt            2000   342,000     82,100       32,600      47,117 
Senior Vice President,  1999   292,000     78,800       27,900      35,781
Ameren, Union Electric  1998   274,000     79,000       25,800      31,947
and Ameren Services

G. L. Randolph          2000   276,000     78,700       14,100      11,729 
Senior Vice President,  1999   236,000     47,800       10,700       6,833
Union Electric          1998   220,000     47,000        9,700       6,294

P. A. Agathen           2000   272,000     71,800       32,600      27,408 
Senior Vice             1999   242,000     65,300       27,900      22,435
President, Ameren       1998   230,000     63,000       25,800      19,644

Includes compensation received as an officer of Ameren and its subsidiaries.
Amount  includes  (a)  matching  contributions  to the  401(k)  plan and (b)
    above-market earnings on deferred compensation, as follows:

                                       (a)           (b)

                  C. W. Mueller      $7,740        $71,681
                  G. L. Rainwater     5,100          4,350
                  D. E. Brandt        7,703         39,414
                  G. L. Randolph      7,654          4,075
                  P. A. Agathen       5,950         21,458


                              OPTION GRANTS IN 2000

                    Number of    % of Total                           Grant
                       Shares       Options                            Date
                    Underlying    Granted to  Exercise               Present
                      Options     Employees    Price   Expiration    Value
         Name       Granted   in 2000     ($/Sh)      Date        ($)
         ----       ----------    -------      ------     ----        ---
C. W. Mueller        108,100        11.29      31.00     2/11/10    448,615
G. L. Rainwater       32,600         3.41      31.00     2/11/10    135,290
D. E. Brandt          32,600         3.41      31.00     2/11/10    135,290
G. L. Randolph        14,100         1.47      31.00     2/11/10     58,515
P. A. Agathen         32,600         3.41      31.00     2/11/10    135,290

Options  relate to Ameren  Common Stock and vest 25% annually  beginning
    February 11,  2002.  Options are
    not transferable.

The Grant Date Present  Values were  determined  using the  binomial  option
    pricing  model,  a derivative of the  Black-Scholes  option  pricing  model.
    Assumptions used for the model are as follows:  an option term of ten years,
    stock  volatility of 17.39%, a dividend yield of 6.61%,  risk-free  interest
    rate of 6.81%, and a vesting restrictions  discount rate of 3% per year over
    the five-year  vesting period.  The Grant Date Present Value  calculation is
    presented in accordance with SEC proxy requirements,  and the Company has no
    way to determine whether the pricing model can properly  determine the value
    of an option.  There is no  assurance  that the value,  if any,  that may be
    realized will be at or near the value  estimated by the model. No value will
    be  realized  by the  optionee  unless the stock  price  increases  from the
    exercise price, in which case shareholders would benefit commensurately.

                        AGGREGATED OPTION EXERCISES IN 2000
                               AND YEAR-END VALUES

                                                                   Value of
              Shares                     Unexercised             In-the-Money
              Acquired    Value             Options                 Options
                 on     Realized        at Year End(#)          at Year End($)
     Name     Exercise     $      Exercisable Unexercisable    Exercisable Unexercisable
     ----     --------  --------  ----------- -------------  ----------- -------------
C. W. Mueller     -        -       55,875     247,325           404,198    2,828,364

G. L. Rainwater   -        -        6,450      79,850            45,553      906,128

D. E. Brandt      -        -       21,050      85,450           151,366      942,228

G. L. Randolph    -        -        8,100      34,400            58,538      386,294

P. A. Agathen     -        -       17,550      85,450           114,834      942,228

These  columns  represent  the excess of the closing  price of the Company's
    Common  Stock of $46.3125  per share,  as of December  29,  2000,  above the
    exercise  price of the options.  The amounts  under the  Exercisable  column
    report  the  "value"  of options  that are  vested  and  therefore  could be
    exercised.  The Unexercisable column reports the "value" of options that are
    not vested and therefore could not be exercised as of December 31, 2000.


Ameren Retirement Plan

      Most salaried employees of Ameren and its subsidiaries earn benefits under
the Ameren  Retirement Plan  immediately  upon  employment.  Benefits  generally
become  vested  after five years of service.  On an annual  basis a  bookkeeping
account in a participant's name is credited with an amount equal to a percentage
of the participant's  pensionable  earnings for the year.  Pensionable  earnings
equals base pay,  overtime and annual  bonuses,  which are equivalent to amounts
shown as "Annual Compensation" in the Summary Compensation Table. The applicable
percentage is based on the  participant's age as of December 31 of that year. If
the participant was an employee prior to July 1, 1998, an additional  transition
credit percentage is credited to the  participant's  account through 2007 (or an
earlier  date if the  participant  had less than 10 years of service on December
31, 1998).

Participant's Age     Regular Credit for      Transition Credit
on December 31     Pensionable Earnings Pensionable Earnings   Total Credits
Less than 30                3%                      1%                   4%

30 to 34                    4%                      1%                   5%

35 to 39                    4%                      2%                   6%

40 to 44                    5%                      3%                   8%

45 to 49                    6%                     4.5%                 10.5%

50 to 54                    7%                      4%                   11%

55 and over                 8%                      3%                   11%

   An additional regular credit of 3% is received for pensionable earnings
   above the Social Security wage base.

      These  accounts also receive  interest  credits based on the average yield
for one-year U.S. Treasury Bills for the previous October, plus 1%. In addition,
certain annuity benefits earned by participants under prior plans as of December
31,  1997  were  converted  to  additional  credit  balances  under  the  Ameren
Retirement Plan as of January 1, 1998. When a participant terminates employment,
the amount credited to the  participant's  account is converted to an annuity or
paid to the  participant in a lump sum. The participant can also choose to defer
distribution, in which case the account balance is credited with interest at the
applicable rate until the future date of distribution.  Benefits are not subject
to any deduction for Social Security or other offset amounts.


      In certain cases pension benefits under the Retirement Plan are reduced to
comply  with  maximum  limitations  imposed  by the  Internal  Revenue  Code.  A
Supplemental   Retirement  Plan  is  maintained  by  Ameren  to  provide  for  a
supplemental benefit equal to the difference between the benefit that would have
been paid if such Code  limitations  were not in effect and the reduced  benefit
payable as a result of such Code limitations.  The plan is unfunded and is not a
qualified plan under the Internal Revenue Code.

      The  following  table  shows the  estimated  annual  retirement  benefits,
including  supplemental  benefits,  which  would be  payable  to each  executive
officer listed if he were to retire at age 65 at his 2000 base salary and annual
bonus, and payments were made in the form of a single life annuity.

          Name             Year of 65th Birthday     Estimated Annual Benefit
      C. W. Mueller              2003                         $383,000

      G. L. Rainwater            2011                          192,000

      D. E. Brandt               2019                          264,000

      G. L. Randolph             2013                          180,000

      P. A. Agathen              2012                           94,000

Change of Control Severance Plan

      Under the Ameren Corporation Change of Control Severance Plan,  designated
officers  of Ameren and its  subsidiaries,  including  current  officers  of the
Company  named in the  Summary  Compensation  Table,  are  entitled  to  receive
severance benefits if their employment is terminated under certain circumstances
within three years after a "change of control". A "change of control" occurs, in
general,  if (i) any  individual,  entity or group  acquires  20% or more of the
outstanding  Common  Stock of  Ameren  or of the  combined  voting  power of the
outstanding  voting  securities  of  Ameren;  (ii)  individuals  who,  as of the
effective date of the Plan,  constitute the Board of Directors of Ameren, or who
have  been  approved  by a  majority  of the  Board,  cease  for any  reason  to
constitute a majority of the Board; or (iii) Ameren enters into certain business
combinations, unless certain requirements are met regarding continuing ownership
of the  outstanding  Common  Stock  and  voting  securities  of  Ameren  and the
membership of its Board of Directors.


      Severance  benefits  are  based  upon a  severance  period of two or three
years,  depending on the officer's  position.  An officer  entitled to severance
will receive the following:  (a) salary and unpaid vacation pay through the date
of  termination;  (b) a pro rata  bonus  for the year of  termination,  and base
salary  and bonus for the  severance  period;  (c)  continued  employee  welfare
benefits for the  severance  period;  (d) a cash payment  equal to the actuarial
value of the additional  benefits the officer would have received under Ameren's
qualified  and  supplemental  retirement  plans if  employed  for the  severance
period;  (e) up to  $30,000  for the  cost  of  outplacement  services;  and (f)
reimbursement  for any excise tax imposed on such  benefits  as excess  payments
under the Internal Revenue Code.

                            AUDITING COMMITTEE REPORT

      The Auditing Committee reviews Ameren  Corporation's  financial  reporting
process on behalf of the Board of Directors. In fulfilling its responsibilities,
the Committee has reviewed and discussed the audited financial  statements to be
included in the 2000 Annual Report on SEC Form 10-K with Ameren's management and
the  independent  accountants.  Management  is  responsible  for  the  financial
statements and the reporting process, including the system of internal controls.
The  independent  accountants  are  responsible for expressing an opinion on the
conformity of those audited  financial  statements  with  accounting  principles
generally accepted in the United States.

          The Auditing Committee has discussed with the independent accountants,
the matters required to be discussed by Statement on Auditing  Standards No. 61,
Communication with Audit Committees,  as amended. In addition, the Committee has
discussed with the independent accountants,  the accountants'  independence from
Ameren and its management  including the matters in the written  disclosures and
the letter required by Independence Standards Board Standard No. 1, Independence
Discussions with Audit  Committees,  received from the independent  accountants.
The Auditing  Committee  has  considered  whether the  independent  accountants'
provision of the services covered under the captions "Independent Accountants" -
"Financial  Information  Systems Design and Implementation  Fees" and "All Other
Fees" in the proxy  statement is compatible with  maintaining  the  accountants'

      In reliance on the reviews and discussions referred to above, the Auditing
Committee recommended to the Board of Directors that the


audited  financial  statements be included in Ameren's Annual Report on SEC Form
10-K for the year ended  December 31, 2000,  for filing with the  Securities and
Exchange Commission.

                                      /s/ Harvey Saligman, Chairman
                                      /s/ Richard A. Liddy
                                      /s/ Richard A. Lumpkin
                                      /s/ Paul L. Miller, Jr.
                                      /s/ Janet McAfee Weakley
                                      /s/ James W. Wogsland


                                PERFORMANCE GRAPH

                         5 Year Cumulative Total Return
                  Ameren Corporation, S&P 500, EEI Index
      Value of $100 invested 12/31/95, including reinvestment of dividends
      YEAR     1995      1996    1997    1998    1999    2000
     ------   -----     ------  ------  ------  ------  ------

AEE             100     132.87  130.33  159.54  166.30  136.80
S&P 500         100     137.50  169.47  226.04  291.05  352.57
EEI Index       100     131.02  132.59  168.88  192.34  156.56

 (1) Information shown for Ameren Corporation prior to 1/1/98 is based on an
     assumed aggregate investment of $100 on 12/31/95 in the Common Stock of the
     companies  whose Common Stock was  exchanged for Ameren Common Stock in the
     Merger,  consisting of $74 invested in Union Electric  Common Stock and $26
     invested in CIPSCO  Incorporated Common Stock. Such amounts were determined
     based upon the percentages,  of the total number of shares of Ameren Common
     Stock  issued in the Merger,  that were issued in exchange for Common Stock
     of Union Electric and CIPSCO Incorporated.

 Edison  Electric  Institute  Index  of  100  investor-owned   electric


                             INDEPENDENT ACCOUNTANTS

Fiscal Year 2000

      PricewaterhouseCoopers LLP served as the Company's independent accountants
in 2000.  Representatives  of the firm are  expected to be present at the annual
meeting  with the  opportunity  to make a  statement  if they so desire  and are
expected to be available to respond to appropriate questions.

      PricewaterhouseCoopers  LLP also served as independent accountants for the
Company's subsidiaries, including Union Electric and CIPS, in 2000.

Audit Fees:

      The    aggregate    fees    billed   or   expected   to   be   billed   by
PricewaterhouseCoopers  LLP for professional  services rendered for the audit of
the Company's annual  financial  statements for fiscal year 2000 and the reviews
of the financial statements included in the Company's Forms 10-Q for such fiscal
year  were  $446,500.  All but  $35,500  of the fees have  been  billed  through
December 31, 2000.

Financial Information Systems Design and Implementation Fees:

      The Company did not engage PricewaterhouseCoopers LLP to provide advice to
the Company regarding  financial  information  systems design and implementation
during the fiscal year ended December 31, 2000.

All Other Fees:

      Fees   and    out-of-pocket    expenses   billed   to   the   Company   by
PricewaterhouseCoopers  LLP during the Company's  2000 fiscal year for all other
non-audit services rendered to the Company totaled $1,006,432.

Fiscal Year 2001

      The Company has not selected its  independent  accountants  for 2001. This
selection is expected to be made by the Board of Directors by the second quarter
of  fiscal  2001  after  consideration  of the  recommendation  of the  Auditing
Committee of the Board of Directors, the present members of which are identified
under "Item (1): Election of Directors" and in the Auditing Committee Report.


                              STOCKHOLDER PROPOSALS

      Any stockholder  proposal intended for inclusion in the proxy material for
the Company's 2002 Annual Meeting of  Stockholders  must be received by November
16, 2001.

      In  addition,  under the  Company's  By-Laws,  stockholders  who intend to
submit a proposal  in person at an Annual  Meeting,  or who intend to nominate a
Director at a meeting,  must  provide  advance  written  notice along with other
prescribed  information.  In  general,  such  notice  must  be  received  by the
Secretary of the Company at the principal  executive  offices of the Company not
later  than 60 or  earlier  than 90 days  prior  to the  meeting.  A copy of the
By-Laws can be obtained by written request to the Secretary of the Company.


      In addition to the use of the mails,  proxies may be solicited by personal
interview,  or by  telephone or other means,  and banks,  brokers,  nominees and
other  custodians  and  fiduciaries  will be  reimbursed  for  their  reasonable
out-of-pocket  expenses in forwarding  soliciting  material to their principals,
the  beneficial  owners of stock of the  Company.  Proxies may be  solicited  by
Directors,  officers  and key  employees  of the  Company on a  voluntary  basis
without  compensation.  The Company will bear the cost of soliciting  proxies on
its behalf.

66149, ST. LOUIS, MISSOURI 63166-6149.

HOME  PAGE  ON  THE  INTERNET  - http://www.ameren.com


                                      A - 3
AMEREN CORPORATION                                                  APPENDIX A

The Auditing Committee shall consist of three or more non-employee  directors of
the Company designated by the Board of Directors who have no relationship to the
Company  that  may  interfere  with the  exercise  of  their  independence  from
management  and the  Company.  The  Auditing  Committee  shall be  approved by a
majority of the whole Board of  Directors  by  resolution  or  resolutions.  The
members of the Auditing  Committee  shall meet the  independence  and experience
requirements of the New York Stock Exchange.  The Auditing  Committee shall have
the authority to retain special legal, accounting or other consultants to advise
the Committee.

It is the Committee's responsibility to:

1.    Recommend to the Board of Directors a firm of independent accountants,
      which firm is  ultimately  accountable  to the Auditing Committee and the
      Board of Directors.

2.    Evaluate  the   Company's   independent   accountants   (and  approve  the
      compensation paid to the independent  accountants) and, where appropriate,
      recommend to the Board of Directors  the  replacement  of the  independent

3.    Ensure that the independent  accountants submit on a periodic basis to the
      Auditing   Committee   a  formal   written   statement   delineating   all
      relationships  between  the  independent  accountants  and the Company and
      actively  engage  in a  dialogue  with the  independent  accountants  with
      respect to any  disclosed  relationships  or services  that may impact the
      accountants'  objectivity and independence;  and, if deemed appropriate by
      the  Auditing  Committee,  recommend  that  the  Board of  Directors  take
      appropriate action to ensure the independence of the accountants.

4.    Review with the  independent  accountants and with management the proposed
      scope of the annual audit  (including  planning and staffing),  past audit
      experience,  the Company's  internal  audit  program,  recently  completed
      internal audits and other matters bearing upon the scope of the audit.

5.    Review and discuss with management and the  independent  accountants the
      annual  audited  financial  statements to be included in the Company's
      Form 10-K filing, including matters regarding accounting and auditing
      principles as well as internal  controls that could have a  significant
      effect on the Company's  financial


      statements  and  any  other  matters required  to be discussed  by the
      Statement on Auditing  Standards  No. 61, as modified or supplemented,
      relating to the conduct of the audit. The Auditing Committee shall also
      recommend to the Board of Directors that the Company's  annual financial
      statements,  together  with  the report of  their independent accountants
      as to their  examination,  be included in the Company's  Annual Report on
      Form 10-K.

6.    The Chairman of the Auditing  Committee,  management  and the  independent
      accountants  will  review and discuss the  Company's  quarterly  financial
      statements  contained in its Form 10-Q prior to filing with the Securities
      and Exchange Commission.

7.    Review  with  management  any  suggestions  and   recommendations  of  the
      independent  accountants  and internal  auditors  concerning the Company's
      auditing  and  accounting  principles  and  practices,   and  management's
      responses to significant findings and recommendations.

8.    Meet on a regular basis with a representative  or  representatives  of the
      Internal  Audit  Department  of the Company and review the Internal  Audit
      Department's Reports of Operations.

9.    Review the independent accountant's assessment of the Company's Internal
      Audit function.

10.   Review the appointment, replacement, reassignment or dismissal of the
      Manager of Internal Audit.

11.   Review  whether the Company's  Statement of Policy on Business  Ethics and
      Conflicts  of Interest  have been  communicated  by the Company to all key
      employees  of the  Company  with a direction  that all such key  employees
      certify that they have read, understand and are not aware of any violation
      of the Statement of Policy on Business Ethics and Conflicts of Interest.

12.   In conjunction  with  management,  the Manager of Internal Audit,  and the
      independent accountants, review significant financial risks to the Company
      and the steps taken to manage such risks.

13.   Review policies and procedures  related to officers' expense accounts and
      perquisites,  including use of corporate assets.

14.   Review legal and  regulatory  matters  that may have a material  effect on
      financial statements,  related Company compliance policies, and reports to


15.   Separately  meet with internal  auditors,  independent  accountants  and
      management at least  annually to review matters requiring private

16.   Meet at least four times per year, or more  frequently  if  circumstances
      require. The Committee may ask members of management or others to attend
      and provide information.

17.   Report its significant activities and actions to the Board of Directors
      on a periodic basis.

18.   Prepare a report for inclusion in the Company's  annual proxy statement as
      required by rules of the Securities and Exchange  Commission and submit it
      to the Board of Directors for approval.

19.   Review and  reassess  the  adequacy of the  Auditing Committee charter on
      an annual basis and submit any recommended changes to the Board of
      Directors for approval.

20.   Obtain from  independent  accountants  assurance  that  Section 10A of the
      Private Securities Litigation Reform Act of 1995 has not been implicated.

The Auditing  Committee's  responsibility  is oversight  and  monitoring  of the
Company's audit,  accounting and financial reporting functions and practices, by
monitoring,  on behalf of the Board,  the  Company's  accounting  and  financial
reporting practices and the Company's system of internal controls; reviewing the
financial   information  and  related  disclosures  that  will  be  provided  to
shareowners;  and  communicating  regularly  with  management  and the Company's
independent outside accountants  regarding such matters.  The Board of Directors
recognizes,  however, that in carrying out its oversight  responsibilities,  the
Auditing  Committee is not providing  any expert or special  assurance as to the
Company's financial statements or any professional  certification as to the work
of the  independent  outside  accountants  engaged by the Company.  The Board of
Directors  further  recognizes that the Company's  management is responsible for
preparing the Company's  financial  statements and that the independent  outside
accountants are responsible for auditing those financial statements.


P. O. BOX 66149, ST. LOUIS, MISSOURI 63166-6149                            PROXY


The undersigned  hereby appoints  CHARLES W. MUELLER and STEVEM R. SULLIVAN, and
either  of  them,  each  with  the  power  of  substitution,  as  proxy  for the
undersigned,  to vote all the  shares of  capital  stock of  AMEREN  CORPORATION
represented  hereby at the Annual Meeting of  Stockholders  to be held at Powell
Symphony Hall, 718 North Grand Boulevard, St. Louis, Missouri, on April 24, 2001
at 9:00 A.M.,  and at any  adjournment  thereof,  upon all  matters  that may be
submitted to a vote of stockholders including the matters described in the proxy
statement furnished herewith, subject to any directions indicated on the reverse
side of this proxy form and in their  discretion on any other matter that may be
submitted to a vote of stockholders.

                              A. HAYS, THOMAS H. JACOBSEN, RICHARD A LIDDY,
                              GORDON R. LOHMAN, RICHARD A. LUMPKIN,
                              JOHN PETERS MacCARTHY, HANNE M. MERRIMAN,
                              PAUL L. MILLER, JR., CHARLES W. MUELLER,
                              W. WOGSLAND

PLEASE VOTE, DATE AND SIGN ON THE REVERSE SIDE hereof and return this proxy form
promptly in the enclosed envelope.  If you attend the meeting and wish to change
your vote, you may do so automatically by casting your ballot at the meeting.

                          SEE REVERSE SIDE

                                   - -  THANK YOU FOR YOUR PROMPT ATTENTION  - -

                                               FOLD AND DETACH HERE

/ x /      Please mark votes                   This proxy will be voted as specified below.  If no direction is made, this
           as in this example.                 proxy will be voted FOR all nominees listed on the reverse side and as
                                               recommended by the Board on the other items listed below.


            FOR all nominees    WITHHOLD AUTHORITY
            (except as listed   all nominees
                                                                                      FOR    AGAINST  ABSTAIN
ITEM 1            /     /          /     /                         ITEM 2            /   /    /   /    /   /
ELECTION OF                                                        REPORT ON CALLAWAY
DIRECTORS                                                          PLANT RELEASES

                                                                        ATTENDANCE CARD REQUESTED      /   /
FOR ALL EXCEPT:__________________________________

                                                         [AMEREN LOGO]             DATED________________2001   REVERSE

                                                                       SIGNATURE - Please sign exactly as name appears hereon.

                                                                       CAPACITY (OR SIGNATURE IF HELD JOINTLY)

                                                                       Shares registered in the name of a Custodian or Guardian
                                                                       must be signed by such.  Executors, administrators,
                                                                       trustees, etc. should so indicate when signing.