[Letterhead of Steven R. Sullivan]

                                 August 23, 2002


Union Electric Company
1901 Chouteau Avenue
St. Louis, Missouri 63103


Ladies and Gentlemen:

         I am Vice President, General Counsel and Secretary of Union Electric
Company, a Missouri corporation (the "COMPANY"). The Company and Union Electric
Capital Trust I, a Delaware business trust, have filed with the Securities and
Exchange Commission (the "COMMISSION") a Registration Statement on Form S-3
(Registration Nos. 333-87506 and 333-87506-01) (the "REGISTRATION STATEMENT")
under the Securities Act of 1933, as amended (the "SECURITIES ACT"), with
respect to up to $750,000,000 maximum aggregate offering price of securities,
which was declared effective by the Commission on August 13, 2002. On August 22,
2002, the Company issued and sold $173,000,000 of its 5.25% Senior Secured Notes
due 2012 (the "NOTES") pursuant to an indenture dated as of August 15, 2002
between the Company and The Bank of New York, as trustee (the "INDENTURE").

         In connection with the issuance and sale of the Notes by the Company, I
have reviewed originals (or copies certified or otherwise identified to my
satisfaction) of the Registration Statement (including the exhibits thereto),
the Restated Articles of Incorporation and By-Laws of the Company as in effect
on the date hereof, the Indenture, a specimen of the Notes, corporate and other
documents, records and papers and certificates of public officials. In
connection with such review, I have assumed the genuineness of all signatures,
the legal capacity of natural persons, the conformity to the originals of the
documents submitted to me as certified or photostatic copies, the authenticity
of the originals of such documents and all documents submitted to me as
originals and the correctness of all statements of fact contained in such
original documents. I am a member of the Bar of the State of Missouri and, for
purposes of this opinion, do not hold myself out as an expert on the laws of any
jurisdiction other than the State of Missouri.

         On the basis of such review, I am of the opinion that the Notes have
been legally issued by the Company and constitute the valid and binding
obligations of the Company, subject to bankruptcy, insolvency, fraudulent
conveyance, reorganization, moratorium and other similar laws affecting
creditors' rights, to general equitable principles (whether considered in a
proceeding in equity or at law) and to an implied covenant of reasonableness,
good faith and fair dealing.




         I hereby consent to the filing of this opinion as an exhibit to the
Company's Current Report on Form 8-K dated August 23, 2002, which is
incorporated by reference in the Registration Statement.


                                          Very truly yours,


                                          /s/ Steven R. Sullivan
                                          -----------------------------------
                                          Steven R. Sullivan
                                          Vice President, General Counsel and
                                          Secretary.