Exhibit F

                 [On Letterhead of Steven R. Sullivan, Esquire]


                                December 18, 2003


Securities and Exchange Commission
450 Fifth Street, NW
Washington, D.C.  20549

         RE:  AMEREN CORPORATION, ET AL. - FILE NO. 70-10159
              ----------------------------------------------

Dear Sirs:

     I refer to the Form U-1 Application/Declaration, as amended (the
"Application"), under the Public Utility Holding Company Act of 1935, as amended
(the "Act"), filed jointly with the Securities and Exchange Commission (the
"Commission") by Ameren Corporation ("Ameren") and certain of its direct and
indirect non-utility subsidiaries (each a "Non-Utility Subsidiary" and
collectively the "Non-Utility Subsidiaries") (Ameren and the Non-Utility
Subsidiaries being collectively referred to as the "Applicants"). I am an
attorney licensed to practice in the State of Missouri and have acted as counsel
for the Applicants in connection with the Application. Capitalized terms used
herein that are not specifically defined herein shall have the meanings ascribed
to them in the Application.

     In the Application, the Applicants request that the Commission grant them
authorization to engage in various transactions (the "Proposed Transactions")
during the period through December 31, 2006. Specifically, the authorizations
relate to the following: (i) the acquisition directly or indirectly by Ameren of
the equity securities of one or more Intermediate Subsidiaries, Financing
Subsidiaries, and Special-Purpose Subsidiaries; (ii) the performance of
Development Activities and Administrative Activities by Non-Utility
Subsidiaries, and expenditure of up to $250 million outstanding at any one time
in connection with Development Activities; (iii) the issuance of up to $300
million in the aggregate amount of guarantees by Non-Utility Subsidiaries, in
addition to any guarantees that are exempt under Rules 45(b) and 52(b) ; (iv)
the sale of goods and services among Non-Utility Subsidiaries at market prices
determined without regard to "cost," as determined in accordance with Rules 90
and 91, in certain specified cases; (v) the sale of certain goods and services
by certain Non-Utility Subsidiaries outside the United States, subject to a
request for reservation of jurisdiction; (vi) the performance of agency services
at "cost" by Ameren Energy, Inc. for Union Electric Company and by Ameren Energy
Marketing Company for AmerenEnergy Resources Generating Company in connection
with brokering and marketing of electricity; (vii) investments by Non-Utility
Subsidiaries in Energy Assets or in the equity securities of companies
substantially all of whose assets consist of such Energy Assets; (viii) the
payment of dividends and/or reacquisition of securities held by associate
companies by Non-Utility Subsidiaries out of capital and unearned surplus, to
the extent permitted by law; (ix) the entering into of Anticipatory Hedges by
Non-Utility Subsidiaries; and (x) changes in capitalization of Non-Utility





Subsidiaries, and consolidation or other reorganization of Non-Utility
Subsidiaries.

     In connection with this opinion, I have examined original, certified, or
conformed copies of all such corporate records, agreements, instruments, and
documents of the Applicants and certificates of public officials and officers of
the Applicants, and have made such other investigations, as I have deemed
necessary or appropriate for the purpose of rendering this opinion. In my
examination, I have assumed the genuineness of all signatures, the authenticity
of all documents submitted to me as originals and the conformity to originals of
all documents submitted to me as conformed copies.

     The opinions expressed below with respect to the Proposed Transactions are
subject to the following assumptions and conditions:

     (a) The Proposed Transactions shall have been duly authorized and approved,
to the extent required by the governing documents and applicable state laws, by
the Board of Directors of Ameren or other Applicant, as appropriate.

     (b) The Commission shall have duly entered an appropriate order or orders
with respect to the Proposed Transactions as described in the Application
granting and permitting the Application to become effective under the Act and
the rules and regulations thereunder and the Proposed Transactions are
consummated in accordance with the Application.

     (c) The parties shall have obtained all consents, waivers and releases, if
any, required for the Proposed Transactions under all applicable governing
corporate documents, contracts, agreements, debt instruments, indentures,
franchises, licenses, and permits.

     (d) No act or event other than as described herein shall have occurred
subsequent to the date hereof which would change the opinions expressed above.

     (e) The consummation of the Proposed Transactions shall be conducted under
my supervision and all legal matters incident thereto shall be satisfactory to
me, including the receipt in satisfactory form of opinions of other counsel,
qualified to practice in jurisdictions pertaining to such Proposed Transactions
in which I am not admitted to practice, as I may deem appropriate.

     Based on the foregoing, and subject to the assumptions and conditions set
forth herein, and having regard to legal considerations which I deem relevant, I
am of the opinion that, in the event that Proposed Transactions are consummated
in accordance with the Application:

     1. All state laws applicable to the Proposed Transactions will have been
complied with;

     2. The Applicants are validly organized and duly existing under the laws of
their respective states of incorporation;

     3. The equity securities to be acquired by the Applicants in the Proposed
Transactions will be validly issued, fully paid and nonassessable, and the
holders thereof will be entitled to the rights and privileges appertaining


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thereto set forth in the applicable certificates of incorporation which define
such rights and privileges;

     4. The guarantees to be issued by Non-Utility Subsidiaries will be valid
and binding obligations of such companies in accordance with the terms of such
guarantees; and

     5. The consummation of the Proposed Transactions will not violate the legal
rights of the holder of any securities issued by Applicants.

     I hereby consent to the use of this opinion in connection with the
Application. The opinions expressed herein are intended solely for the benefit
of the Commission and may not be relied upon for any purpose by any other
person.



                                       Sincerely,


                                       /s/ Steven R. Sullivan