EXHIBIT 4.7



                                                                [Conformed Copy]
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                             UNION ELECTRIC COMPANY



                                       TO



                            BOATMEN'S TRUST COMPANY

                                   AS TRUSTEE



                             SUPPLEMENTAL INDENTURE

                              Dated August 1, 1993

                                   ----------


                             First Mortgage Bonds,

                             7.15% Series due 2023

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                             UNION ELECTRIC COMPANY
                             SUPPLEMENTAL INDENTURE

                              DATED AUGUST 1, 1993

                             ----------------------

             INSERTED FOR CONVENIENCE ONLY AND NOT AS A PART OF THE
                  SUPPLEMENTAL INDENTURE DATED AUGUST 1, 1993


 
                                                                   Page
                                                                   ----
                                                                
     Parties......................................................   1
     Recitals.....................................................   1
     Granting Clauses.............................................   8
     Habendum.....................................................  11
     Subject to Certain Exceptions................................  11
     Grant in Trust...............................................  11
     General Covenant.............................................  11
 
                                   ARTICLE I

                          Description of The New Bonds

     Sec. 1. General description of the New Bonds.............  11
     Sec. 2. Denominations and dating the New Bonds, privilege
               of exchange and other matters..................  12
     Sec. 3. Form of face of the New Bond.....................  13
             Form of Trustee's Certificate....................  14
             Form of reverse of the New Bond..................  15
     Sec. 4. Execution of and form of the New Bonds in
               temporary form.................................  18


                                       i

 
                                   ARTICLE II

                             Issue of The New Bonds


                                            Page
                                            ----
                                                                         
     Sec.    1.  Limitation as to principal amount..............................  18
     Sec.    2.  Initial issue of $75,000,000 aggregate
                 principal amount of the New Bonds..............................  18

                                  ARTICLE III

                                  Redemption of the New Bonds
                                                                         
     Sec.    1.  New Bonds redeemable...........................................  19
                 No improvement, maintenance or analogous
                 fund for the New Bonds.........................................  19
     Sec.    2.  Notice of Redemption...........................................  19

                                       ARTICLE IV

                                        Covenants
                                                                         
     Sec.    1.  Of seisin and title............................................  19
     Sec.    2.  Earnings test required for issue of additional Bonds...........  20
     Sec.    3.  Exclusion of $22,500,000 from net bondable value of property
                 additions available for purposes of the Original Indenture.....  20
     Sec.    4.  Against issuance of additional prior lien bonds secured by
                 unfunded prior liens except under certain conditions...........  20
     Sec.    5.  Against acquisition of property subject to unfunded prior liens
                 except under certain conditions................................  21


                                       ii

 
                                   ARTICLE V

                                  The Trustee
 
 
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                                                                                ----
                                                                              
   Acceptance of trusts by Trustee.............................................  21
   Trustee not responsible for validity of Supplemental Indenture..............  22



                                   ARTICLE VI

              Consents and Agreements of Holders of The New Bonds
                               to Certain Matters
 
     Consent and Agreement to amendments contained in Article VII of the
      Supplemental Indenture dated February 1, 1974 on effective date of
      this Article.............................................................  22
     Definition of "Nuclear fuel"..............................................  22
     Definition of "Permitted liens"...........................................  23
     Definition of "Property additions"........................................  23
     Relating to subdivision (4) of subparagraph (f) of Section 4 of
      Article III of the Original Indenture....................................  23
     Relating to subparagraph (a) of Section 2 of Article VII of the Original
      Indenture................................................................  23
     Effective date of Article VI..............................................  23
 


                                      iii

 
                                  ARTICLE VII

                        Reservations by Company to Amend
                               Original Indenture
                                                                            Page
                                                                            ----

     Sec. 1.  Substitution of 60% for 80% wherever appearing in Article XV
                 of the Original Indenture.................................   24
     Sec. 2.  Reservation of right to amend Article XV of the Original
                 Indenture by adding a new Section 9 thereto...............   24
 

                                 ARTICLE VIII

                           Miscellaneous Provisions
 
     Sec. 1.  Meanings of terms in Supplemental Indenture.................    26
     Sec. 2.  Execution of Supplemental Indenture in counterparts.........    26
     Testimonium..........................................................    26
     Execution............................................................    27
     Acknowledgements.....................................................    28
                                       
                                      iv

 
           SUPPLEMENTAL INDENTURE, dated the 1st day of August, One thousand
        nine hundred and ninety-three (1993) made by and between UNION ELECTRIC
        COMPANY, a corporation organized and existing under the laws of the
        State of Missouri (hereinafter called the "Company"), party of the first
        part, and BOATMEN'S TRUST COMPANY, a corporation organized and existing
        under the laws of the State of Missouri (hereinafter called the
        "Trustee"), as Trustee under the Indenture of Mortgage and Deed of Trust
        dated June 15, 1937, hereinafter mentioned, party of the second part:

           WHEREAS, the Company has heretofore executed and delivered to the
        Trustee its Indenture of Mortgage and Deed of Trust, dated June 15,
        1937, to secure the payment of the principal of and the interest (and
        premium, if any) on all bonds at any time issued and outstanding
        thereunder; and indentures supplemental thereto dated June 15, 1937, May
        1, 1941, March 17, 1942, April 13, 1945, April 27, 1945, October 1,
        1945, April 11, 1947, April 13, 1949, September 13, 1950, December 1,
        1950, September 20, 1951, May 1, 1952, March 1, 1954, May 1, 1955,
        August 31, 1955, April 1, 1956, July 1, 1956, August 1, 1957, February
        1, 1958, March 1, 1958, November 5, 1958, March 16, 1959, June 24, 1959,
        December 11, 1959, August 17, 1960, September 1, 1960, October 24, 1960,
        June 30, 1961, July 1, 1961, August 9, 1962, September 30, 1963,
        November 1, 1963, March 12, 1965, April 1, 1965, April 14, 1966, May 1,
        1966, February 17, 1967, March 1, 1967, February 19, 1968, March 15,
        1968, August 21, 1968, April 7, 1969, May 1, 1969, September 12, 1969,
        October 1, 1969, March 26, 1970, April 1, 1970, June 12, 1970, January
        1, 1971, April 1, 1971, September 15, 1971, December 3, 1973, February
        1, 1974, April 25, 1974, February 3, 1975, March 1, 1975, June 11, 1975,
        May 12, 1976, August 16, 1976, April 26, 1977, October 15, 1977,
        November 7, 1977, December 1, 1977, August 1, 1978, October 12, 1979,
        November 1, 1979, July 7, 1980, August 1, 1980, August 20, 1980,
        February 1, 1981, October 8, 1981, August 27, 1982, September 1, 1982,
        December 15, 1982, March 1, 1983, June 21, 1984, December 12, 1984, June
        11, 1985, March 1, 1986, May 1, 1986, May 1, 1990, December 1, 1991,
        December 4, 1991, January 1, 1992, September 30, 1992, October 1, 1992,
        December 1, 1992, February 1, 1993, February 18, 1993, and May 1, 1993
        respectively, have heretofore been entered into between the Company and
        the Trustee (said Indenture of Mortgage and Deed of Trust, as amended
        and supplemented by said Supplemental Indentures being hereinafter
        sometimes referred to as the "Original Indenture"); and

           WHEREAS, Bonds have heretofore been issued by the Company under the
        Original Indenture as follows:

             (1) $80,000,000 principal amount of First Mortgage and Collateral
           Trust Bonds, 3 3/4% Series due 1962, all of which have been redeemed
           prior to the date of the execution hereof;

                                      -1-

 
             (2) $90,000,000 principal amount of First Mortgage and Collateral
           Trust Bonds, 3 3/8% Series due 1971, which are described in the
           Supplemental Indenture dated May 1, 1941 (hereinafter called the
           "Supplemental Indenture of May 1, 1941"), all of which have been paid
           at maturity prior to the date of the execution hereof;

             (3) $13,000,000 principal amount of First Mortgage and Collateral
           Trust Bonds, 2 3/4% Series due 1975 (herein called the "Bonds of 1975
           Series"), which are described in the Supplemental Indenture dated
           October 1, 1945 (hereinafter called the "Supplemental Indenture of
           October 1, 1945"), all of which have been paid at maturity prior to
           the date of the execution hereof;

             (4) $25,000,000 principal amount of First Mortgage and Collateral
           Trust Bonds, 2 7/8% Series due 1980 (herein called the "Bonds of 1980
           Series"), which are described in the Supplemental Indenture dated
           December 1, 1950 (hereinafter called the "Supplemental Indenture of
           December 1, 1950"), all of which have been paid at maturity prior to
           the date of the execution hereof;

             (5) $30,000,000 principal amount of First Mortgage and Collateral
           Trust Bonds, 3 1/4% Series due 1982 (herein called the "Bonds of 1982
           Series"), which are described in the Supplemental Indenture dated May
           1, 1952 (hereinafter called the "Supplemental Indenture of May 1,
           1952"), all of which have been paid at maturity prior to the date of
           the execution hereof;

             (6) $40,000,000 principal amount of First Mortgage Bonds, 3 3/4%
           Series due 1986 (herein called the "Bonds of 1986 Series"), which are
           described in the Supplemental Indenture dated July 1, 1956
           (hereinafter called the "Supplemental Indenture of July 1, 1956"),
           all of which have been paid at maturity prior to the date of the
           execution hereof;

             (7) $35,000,000 principal amount of First Mortgage Bonds, 4 3/8%
           Series due 1988 (herein called the "Bonds of 1988 Series"), which are
           described in the Supplemental Indenture dated March 1, 1958
           (hereinafter called the "Supplemental Indenture of March 1, 1958"),
           all of which have been paid at maturity prior to the date of the
           execution hereof;

             (8) $50,000,000 principal amount of First Mortgage Bonds, 4 3/4%
           Series due 1990 (herein called the "Bonds of 1990 Series"), which are
           described in the Supplemental Indenture dated September 1, 1960
           (hereinafter called the "Supplemental Indenture of September 1,
           1960"), all of which have been paid at maturity prior to the date of
           the execution hereof;

             (9) $30,000,000 principal amount of First Mortgage Bonds, 4 3/4%
           Series due 1991 (herein called the "Bonds of 1991 Series"), which are
           described in the Supplemental Indenture dated July 1, 1961
           (hereinafter called the

                                      -2-

 
           "Supplemental Indenture of July 1, 1961"), all of which have been
           paid at maturity prior to the date of the execution hereof;

             (10) $30,000,000 principal amount of First Mortgage Bonds, 4 1/2%
           Series due 1993 (herein called the "Bonds of 1993 Series"), which are
           described in the Supplemental Indenture dated November 1, 1963
           (hereinafter called the "Supplemental Indenture of November 1,
           1963"), all of which have been redeemed prior to the date of the
           execution hereof;

             (11) $35,000,000 principal amount of First Mortgage Bonds, 4 1/2%
           Series due 1995 (herein called the "Bonds of 1995 Series"), which are
           described in the Supplemental Indenture dated April 1, 1965
           (hereinafter called the "Supplemental Indenture of April 1, 1965"),
           all of which are outstanding at the date of the execution hereof;

             (12) $30,000,000 principal amount of First Mortgage Bonds, 5 1/2%
           Series due 1996 (herein called the "Bonds of 1996 Series"), which are
           described in the Supplemental Indenture dated May 1, 1966
           (hereinafter called the "Supplemental Indenture of May 1, 1966"), all
           of which are outstanding at the date of the execution hereof;

             (13) $40,000,000 principal amount of First Mortgage Bonds, 5 1/2%
           Series due 1997 (herein called the "Bonds of 1997 Series"), which are
           described in the Supplemental Indenture dated March 1, 1967
           (hereinafter called the "Supplemental Indenture of March 1, 1967"),
           all of which are outstanding at the date of the execution hereof;

             (14) $50,000,000 principal amount of First Mortgage Bonds, 7%
           Series due 1998 (herein called the "Bonds of 1998 Series"), which are
           described in the Supplemental Indenture dated March 15, 1968
           (hereinafter called the "Supplemental Indenture of March 15, 1968"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (15) $35,000,000 principal amount of First Mortgage Bonds, 7 3/8%
           Series due 1999 (herein called the "Bonds of May 1999 Series"), which
           are described in the Supplemental Indenture dated May 1, 1969
           (hereinafter called the "Supplemental Indenture of May 1, 1969"), all
           of which have been redeemed prior to the date of the execution
           hereof;

             (16) $40,000,000 principal amount of First Mortgage Bonds, 8 1/4%
           Series due 1999 (herein called the "Bonds of October 1999 Series"),
           which are described in the Supplemental Indenture dated October 1,
           1969 (hereinafter called the "Supplemental Indenture of October 1,
           1969"), all of which have been redeemed prior to the date of the
           execution hereof;

                                      -3-

 
             (17) $100,000,000 principal amount of First Mortgage Bonds, 9.95%
           Series due 1999 (herein called the "Bonds of November 1999 Series"),
           which are described in the Supplemental Indenture dated November 1,
           1979 (hereinafter called the "Supplemental Indenture of November 1,
           1979"), all of which have been redeemed prior to the date of the
           execution hereof;

             (18) $60,000,000 principal amount of First Mortgage Bonds, 9%
           Series due 2000 (herein called the "Bonds of 2000 Series"), which are
           described in the Supplemental Indenture dated April 1, 1970
           (hereinafter called the "Supplemental Indenture of April 1, 1970"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (19) $50,000,000 principal amount of First Mortgage Bonds, 7 7/8%
           Series due 2001 (herein called the "Bonds of January 2001 Series"),
           which are described in the Supplemental Indenture dated January 1,
           1971 (hereinafter called the "Supplemental Indenture of January 1,
           1971"), all of which have been redeemed prior to the date of the
           execution hereof;

             (20) $50,000,000 principal amount of First Mortgage Bonds, 7 5/8%
           Series due 2001 (herein called the "Bonds of April 2001 Series"),
           which are described in the Supplemental Indenture dated April 1, 1971
           (hereinafter called the "Supplemental Indenture of April 1, 1971"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (21) $60,000,000 principal amount of First Mortgage Bonds, 8 1/8%
           Series due 2001 (herein called the "Bonds of October 2001 Series"),
           which are described in the Supplemental Indenture dated September 15,
           1971 (hereinafter called the "Supplemental Indenture of September 15,
           1971"), all of which have been redeemed prior to the date of the
           execution hereof;

             (22) $70,000,000 principal amount of First Mortgage Bonds, 8 3/8%
           Series due 2004 (herein called the "Bonds of 2004 Series"), which are
           described in the Supplemental Indenture dated February 1, 1974
           (hereinafter called the "Supplemental Indenture of February 1,
           1974"), all of which have been redeemed prior to the date of the
           execution hereof;

             (23) $70,000,000 principal amount of First Mortgage Bonds, 10 1/2%
           Series due 2005 (herein called the "Bonds of 2005 Series"), which are
           described in the Supplemental Indenture dated March 1, 1975
           (hereinafter called the "Supplemental Indenture of March 1, 1975"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (24) $70,000,000 principal amount of First Mortgage Bonds, 8 7/8%
           Series due 2006 (herein called the "Bonds of 2006 Series"), which are
           described in the Supplemental Indenture dated August 16, 1976
           (hereinafter called the

                                      -4-

 
           "Supplemental Indenture of August 16, 1976"), all of which have been
           redeemed prior to the date of the execution hereof;

             (25) $27,085,000 principal amount of First Mortgage Bonds, 5.80%
           Environmental Improvement Series 1977, which are described in the
           Supplemental Indenture dated October 15, 1977 (hereinafter called the
           "Supplemental Indenture of October 15, 1977"), all of which have been
           redeemed prior to the date of the execution hereof;

             (26) $60,000,000 principal amount of First Mortgage Bonds, 8 5/8%
           Series due 2007 (herein called the "Bonds of 2007 Series"), which are
           described in the Supplemental Indenture dated December 1, 1977
           (hereinafter called the "Supplemental Indenture of December 1,
           1977"), all of which have been redeemed prior to the date of the
           execution hereof;

             (27) $55,000,000 principal amount of First Mortgage Bonds, 9.35%
           Series due 2008 (herein called the "Bonds of 2008 Series"), which are
           described in the Supplemental Indenture dated August 1, 1978
           (hereinafter called the "Supplemental Indenture of August 1, 1978"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (28) $60,000,000 principal amount of First Mortgage Bonds,
           Environmental Improvement Series 1980, which are described in the
           Supplemental Indenture dated August 1, 1980 (hereinafter called the
           "Supplemental Indenture of August 1, 1980"), all of which have been
           redeemed prior to the date of the execution hereof;

             (29) $150,000,000 principal amount of First Mortgage Bonds, 15 3/8%
           Series due 1991 (herein called the "Bonds of February 1991 Series"),
           which are described in the Supplemental Indenture dated February 1,
           1981 (hereinafter called the "Supplemental Indenture of February 1,
           1981"), all of which have been redeemed prior to the date of the
           execution hereof;

             (30) $125,000,000 principal amount of First Mortgage Bonds, 15%
           Series due 1992 (herein called the "Bonds of 1992 Series"), which are
           described in the Supplemental Indenture dated September 1, 1982
           (hereinafter called the "Supplemental Indenture of September 1,
           1982"), all of which have been redeemed prior to the date of the
           execution hereof;

             (31) $100,000,000 principal amount of First Mortgage Bonds, 13%
           Series due 2013 (herein called the "Bonds of 2013 Series"), which are
           described in the Supplemental Indenture dated March 1, 1983
           (hereinafter called the "Supplemental Indenture of March 1, 1983"),
           all of which have been redeemed prior to the date of the execution
           hereof;

                                      -5-

 
             (32) $100,000,000 principal amount of First Mortgage Bonds, 9 3/8%
           Series due 2016 (herein called the "Bonds of 2016 Series"), which are
           described in the Supplemental Indenture dated March 1, 1986
           (hereinafter called the "Supplemental Indenture of March 1, 1986"),
           all of which have been redeemed prior to the date of the execution
           hereof;

             (33) $100,000,000 principal amount of First Mortgage Bonds, 8 7/8%
           Series due 1996 (herein called the "Bonds of 1996 Series"), which are
           described in the Supplemental Indenture dated May 1, 1986
           (hereinafter called the "Supplemental Indenture of May 1, 1986"), all
           of which have been redeemed prior to the date of the execution
           hereof;

             (34) $60,000,000 principal amount of First Mortgage Bonds,
           Environmental Improvement Series 1990A, which are described in the
           Supplemental Indenture dated May 1, 1990 (hereinafter called the
           "Supplemental Indenture of May 1, 1990"), all of which are
           outstanding at the date of the execution hereof;

             (35) $125,000,000 principal amount of First Mortgage Bonds, 8 3/4%
           Series due 2021 (herein called the "Bonds of 2021 Series"), which are
           described in the Supplemental Indenture dated December 1, 1991
           (hereinafter called the "Supplemental Indenture of December 1,
           1991"), all of which are outstanding at the date of the execution
           hereof;

             (36) $75,000,000 principal amount of First Mortgage Bonds, 8.33%
           Series due 2002 (herein called the "Bonds of 2002 Series"), which are
           described in the Supplemental Indenture dated December 4, 1991
           (hereinafter called the "Supplemental Indenture of December 4,
           1991"), all of which are outstanding at the date of the execution
           hereof;

             (37) $100,000,000 principal amount of First Mortgage Bonds, 7.65%
           Series due 2003 (herein called the "Bonds of 2003 Series"), which are
           described in the Supplemental Indenture dated January 1, 1992
           (hereinafter called the "Supplemental Indenture of January 1, 1992"),
           all of which are outstanding at the date of the execution hereof;

             (38) $204,000,000 aggregate principal amount of First Mortgage
           Bonds, consisting of $100,000,000 principal amount of 6 3/4% Series
           due 1999 and $104,000,000 principal amount of 8 1/4% Series due 2022
           (herein called the "Bonds of 1999 Series" and "Bonds of 2022 Series",
           respectively), which are described in the Supplemental Indenture
           dated October 1, 1992 (hereinafter called the "Supplemental Indenture
           of October 1, 1992"), all of which are outstanding at the date of the
           execution hereof; and

             (39) $170,000,000 aggregate principal amount of First Mortgage
           Bonds, consisting of $85,000,000 principal amount of 7 3/8% Series
           due 2004 and

                                      -6-

 
           $85,000,000 principal amount of 8% Series due 2022 (herein called the
           "Bonds of December 2004 Series" and "Bonds of December 2022 Series",
           respectively, which are described in the Supplemental Indenture dated
           December 1, 1992, (hereinafter called the "Supplemental Indenture of
           December 1, 1992), all of which are outstanding at the date of the
           execution hereof;

             (40) $188,000,000 principal amount of First Mortgage Bonds, 6 7/8%
           Series due 2004 (herein called the "Bonds of August 2004 Series"),
           which are described in the Supplemental Indenture dated February 1,
           1993 (hereinafter called the "Supplemental Indenture of February 1,
           1993"), all of which are outstanding at the date of the execution
           hereof; and

             (41) $148,000,000 principal amount of First Mortgage Bonds, 6 3/4%
           Series due 2008 (herein called the "Bonds of May 2008 Series"), which
           are described in the Supplemental Indenture dated May 1, 1993
           (hereinafter called the "Supplemental Indenture of May 1, 1993"), all
           of which are outstanding at the date of the execution hereof;

        and

           WHEREAS, the Company on August 31, 1955 acquired all of the
        properties of Union Electric Power Company, the Subsidiary as defined in
        Article I of the Original Indenture, upon the dissolution of the
        Subsidiary; the Company, by Supplemental Indenture dated August 31,
        1955, conveyed all of the properties so acquired (other than property of
        the character defined as excepted property in the granting clauses of
        the Original Indenture) to the Trustee upon the terms and trusts in the
        Original Indenture and the indentures supplemental thereto set forth for
        the equal and proportionate benefit and security of all present and
        future holders of the Bonds and coupons issued and to be issued
        thereunder, all the shares of stock of the Subsidiary were released from
        the lien of the Original Indenture; and the Company became entitled to
        change the general designation of the Bonds so as to omit the words "and
        Collateral Trust"; and

           WHEREAS, the Articles of Incorporation of the Company were duly
        amended on April 23, 1956, to change its corporate name from "Union
        Electric Company of Missouri" to "Union Electric Company"; and

           WHEREAS, the Articles of Agreement of the Trustee were duly amended
        effective on January 4, 1982 to change its corporate name from "St.
        Louis Union Trust Company" to "Centerre Trust Company of St. Louis", and
        further amended on December 9, 1988 to change its corporate name from
        "Centerre Trust Company of St. Louis" to "Boatmen's Trust Company"; and

           WHEREAS, the Company is entitled at this time to have authenticated
        and delivered additional Bonds on the basis of the deposit of cash upon
        compliance

                                      -7-

 
        with and pursuant to the provisions of Section 5 of Article III of the
        Original Indenture; and

           WHEREAS, the Company desires by this Supplemental Indenture to
        provide for the creation of a new series of Bonds under the Original
        Indenture, to have the designation provided in Article I, Section 1
        hereof (herein called the "New Bonds"), and the Original Indenture
        provides that certain terms and provisions, as determined by the Board
        of Directors of the Company, of the Bonds of any particular series may
        be expressed in and provided by the execution of an appropriate
        supplemental indenture; and

           WHEREAS, the Company also desires by this Supplemental Indenture to
        continue in effect with respect to the holders of the New Bonds the
        amendments of the Original Indenture contained in the Supplemental
        Indenture dated February 1, 1974, as set forth in Article VII hereof;
        and

           WHEREAS, the Company also desires by this Supplemental Indenture to
        reserve the right to amend the provisions of Article XV of the Original
        Indenture to establish new procedures concerning amendments thereof; and

           WHEREAS, the Original Indenture provides that the Company and the
        Trustee may enter into indentures supplemental to the Original Indenture
        specifically to convey, transfer and assign to the Trustee and to
        subject to the lien of the Original Indenture additional properties
        acquired by the Company; and

           WHEREAS, the Company, in the exercise of the powers and authority
        conferred upon and reserved to it under the provisions of the Original
        Indenture and pursuant to appropriate resolutions of the Board of
        Directors, has duly resolved and determined to make, execute and deliver
        to the Trustee a Supplemental Indenture in the form hereof for the
        purposes herein provided; and

           WHEREAS, all conditions and requirements necessary to make this
        Supplemental Indenture a valid, binding and legal instrument have been
        done, performed and fulfilled and the execution and delivery hereof have
        been in all respects duly authorized;

           NOW, THEREFORE, THIS INDENTURE WITNESSETH:

           That, in consideration of the premises and of the mutual covenants
        herein contained and of the acceptance of this trust by the Trustee and
        of the sum of One Dollar duly paid by the Trustee to the Company at or
        before the time of the execution of this Supplemental Indenture, and of
        other valuable considerations, the receipt whereof is hereby
        acknowledged, and in order further to secure the payment of the
        principal of and interest (and premium, if any) on all Bonds at any time
        issued and outstanding under the Original Indenture, according to their

                                      -8-

 
        tenor and effect, the Company has executed and delivered this
        Supplemental Indenture and has granted, bargained, sold, warranted,
        aliened, remised, released, conveyed, assigned, transferred, mortgaged,
        pledged, set over and confirmed and by these presents does grant,
        bargain, sell warrant, alien, remise, release, convey, assign, transfer,
        mortgage, pledge, set over and confirm unto Boatmen's Trust Company, as
        Trustee, and to its successors in trust under the Original Indenture
        forever, all and singular the following described properties (in
        addition to all other properties heretofore subjected to the lien of the
        Original Indenture and not heretofore released from the lien thereof) -
        that is to say:


                                     FIRST.

           ALL power houses, plants, buildings and other structures, dams, dam
        sites, substations, heating plants, gas works, holders and tanks,
        together with all and singular the electric, heating, gas and mechanical
        appliances appurtenant thereto of every nature whatsoever, now owned by
        the Company, including all and singular the machinery, engines, boilers,
        furnaces, generators, dynamos, turbines and motors, and all and every
        character of mechanical appliance for generating or producing
        electricity, steam, gas and other agencies for light, heat, cold, or
        power or other purposes, and all transmission and distribution systems
        used for the transmission and distribution of electricity, steam, gas
        and other agencies for light, heat, cold or power or any other purpose
        whatsoever, whether underground or overhead, surface or otherwise, now
        owned by the Company, including all poles, towers, posts, wires, cables,
        conduits, manholes, mains, pipes, tubes, drains, furnaces, switchboards,
        transformers, conductors, insulators, supports, meters, lamps, fuses,
        junction boxes, regulator stations, and other electric, steam and gas
        fixtures and apparatus; all of the aforementioned property being located
        in the City of St. Louis, the counties of Adair, Audrain, Benton,
        Bollinger, Boone, Butler, Caldwell, Callaway, Camden, Cape Girardeau,
        Clark, Clay, Clinton, Cole, Cooper, Crawford, Daviess, Dunklin,
        Franklin, Gasconade, Howard, Iron, Jefferson, Knox, Lewis, Lincoln,
        Livingston, Macon, Madison, Maries, Marion, Miller, Mississippi,
        Moniteau, Montgomery, Morgan, New Madrid, Osage, Pemiscot, Perry,
        Pettis, Phelps, Pike, Pulaski, Ralls, Randolph, Ray, Reynolds, Ripley,
        St. Charles, St. Francois, Ste. Genevieve, St. Louis, Saline, Schuyler,
        Scott, Stoddard, Warren, Washington, and Wayne, Missouri, the counties
        of Adams, Alexander, Calhoun, Franklin, Hancock, Henderson, Jackson,
        Jersey, Macoupin, Madison, Massac, Monroe, Perry, Pike, Pulaski, St.
        Clair, Union, and Washington, Illinois, and the counties of Des Moines,
        Henry, Johnson, Lee, and Washington, Iowa, upon real estate owned by the
        Company, or occupied by it under rights to so occupy, which real estate
        is described in the Indenture of Mortgage and Deed of Trust dated June
        15, 1937, in the Supplemental Indentures dated May 1, 1941, March 17,
        1942, April 13, 1945, April 27, 1945, October 1, 1945, April 11, 1947,
        April 13, 1949, September 13, 1950, December 1, 1950, September 20,
        1951, May 1, 1952, March 1, 1954, May 1, 1955, August 31, 1955, April 1,
        1956, July 1, 1956, August 1, 1957, February

                                      -9-

 
        1, 1958, March 1, 1958, November 5, 1958, March 16, 1959, June 24, 1959,
        December 11, 1959, August 17, 1960, September 1, 1960, October 24, 1960,
        June 30, 1961, July 1, 1961, August 9, 1962, September 30, 1963,
        November 1, 1963, March 12, 1965, April 1, 1965, April 14, 1966, May 1,
        1966, February 17, 1967, March 1, 1967, February 19, 1968, March 15,
        1968, August 21, 1968, April 7, 1969, May 1, 1969, September 12, 1969,
        October 1, 1969, March 26, 1970, April 1, 1970, January 1, 1971, April
        1, 1971, September 15, 1971, December 3, 1973, February 1, 1974, April
        25, 1974, February 3, 1975, March 1, 1975, June 11, 1975, May 12, 1976,
        August 16, 1976, April 26, 1977, October 15, 1977, November 7, 1977,
        December 1, 1977, August 1, 1978, October 12, 1979, November 1, 1979,
        July 7, 1980, August 1, 1980, August 20, 1980, February 1, 1981, October
        8, 1981, August 27, 1982, September 1, 1982, December 15, 1982, March 1,
        1983, June 21, 1984, December 12, 1984, June 11, 1985, March 1, 1986,
        May 1, 1986, May 1, 1990, December 1, 1991, December 4, 1991, January 1,
        1992, September 30, 1992, October 1, 1992, December 1, 1992, February 1,
        1993, February 18, 1993, May 1, 1993 and in this Supplemental Indenture,
        or attached to or connected with such real estate or transmission or
        distribution systems of the Company leading from or into such real
        estate.

                                    SECOND.

           ALSO (except as in the Original Indenture expressly excepted) all
        franchises and all permits, ordinances, easements, privileges,
        immunities and licenses, all rights to construct, maintain and operate
        overhead, surface and underground systems for the distribution and
        transmission of electricity, steam, gas or other agencies for the supply
        to itself or others of light, heat, cold or power, all rights-of-way,
        all waters, water rights and flowage rights and all grants and consents,
        now owned or, subject to the provisions of Article XII of the Original
        Indenture, which it may hereafter acquire.

           ALSO, (except as in the Original Indenture expressly excepted) all
        inventions, patent rights and licenses of every kind now owned by the
        Company or, subject to the provisions of Article XII of the Original
        Indenture, which it may hereafter acquire.

                                     THIRD.

           ALSO, subject to the provisions of Article XII of the Original
        Indenture, all other property, real, personal and mixed (except as
        therein or herein expressly excepted) of every nature and kind and
        wheresoever situated now or hereafter possessed by or belonging to the
        Company, or to which it is now, or may at any time hereafter be, in any
        manner entitled at law or in equity.

                                      -10-

 
           TO HAVE AND TO HOLD all said properties, real, personal and mixed,
        mortgaged, pledged and conveyed by the Company as aforesaid, or intended
        so to be, unto the Trustee and its successors and assigns forever;

           SUBJECT, HOWEVER, to the exceptions and reservations and matters
        hereinabove recited, to existing leases, to existing liens upon rights
        of way for transmission or distribution line purposes, as defined in
        Article I of the Original Indenture, and any extensions thereof, and
        subject to existing easements for streets, alleys, highways, rights-of-
        way and railroad purposes over, upon and across certain of the property
        hereinbefore described, and subject also to all the terms, conditions,
        agreements, covenants, exceptions and reservations expressed or provided
        in the deeds or other instruments respectively under and by virtue of
        which the Company acquired the properties hereinabove described, and to
        undetermined liens and charges, if any, incidental to construction or
        other existing permitted liens as defined in Article I of the Original
        Indenture;

           IN TRUST, NEVERTHELESS, upon the terms and trusts in the Original
        Indenture and the indentures supplemental thereto, including this
        Supplemental Indenture, set forth, for the equal and proportionate
        benefit and security of all present and future holders of the Bonds and
        coupons issued and to be issued thereunder, or any of them, without
        preference of any of said Bonds and coupons of any particular series
        over the Bonds and coupons of any other series, by reason of priority in
        the time of the issue, sale or negotiation thereof, or by reason of the
        purpose of issue or otherwise howsoever, except as otherwise provided in
        Section 2 of Article IV of the Original Indenture.

           AND IT IS HEREBY COVENANTED, DECLARED AND AGREED, by and between the
        parties hereto, for the benefit of those who shall hold the Bonds and
        coupons, or any of them to be issued under the Original Indenture, as
        follows:


                                   ARTICLE I.

                          DESCRIPTION OF THE NEW BONDS

           SECTION 1.  There is hereby created a new series of Bonds to be
        executed, authenticated and delivered under and secured by the Original
        Indenture which shall, subject to the provisions of Section 1 of Article
        II of the Original Indenture, be designated as "First Mortgage Bonds,
        7.15% Series due 2023" (the "New Bonds") of the Company.  The New Bonds
        shall be executed, authenticated and delivered in accordance with the
        provisions of, and shall in all respects be subject to all of the terms,
        conditions and covenants of, the Original Indenture.

           The New Bonds shall mature August 1, 2023, and shall bear interest at
        the rate per annum set forth in the form of the New Bond contained in
        Section 3 of

                                      -11-

 
        this Article I, payable semi-annually on the first day of February and
        the first day of August in each year.  The New Bonds shall be payable as
        to principal, premium, if any, and interest in any coin or currency of
        the United States of America which at the time of payment is legal
        tender for public and private debts, and shall be payable at the office
        of the Company in the City of St. Louis, Missouri; provided, however,
        that at the option of the Company, interest on the New Bonds may be paid
        by checks mailed to the registered holder in whose name such Bonds are
        registered at the address as it shall appear on the transfer register of
        the Company.

           SECTION 2.  The New Bonds shall be registered Bonds without coupons,
        of the denomination of $1,000 or any integral multiple thereof.

           The New Bonds shall be transferable and exchangeable for the New
        Bonds of other denominations, as in the Original Indenture provided,
        except that payment of a service charge therefor will not be required by
        the Company.

           Notwithstanding the provisions of Section 6 of Article II of the
        Original Indenture, the New Bonds shall be dated the date of
        authentication and shall bear interest from the interest payment date to
        which interest on the New Bonds has been paid next preceding the date
        thereof, unless such date is an interest payment date to which interest
        has been paid, in which case they shall bear interest from the date
        thereof, or unless the date thereof is prior to February 1, 1994, in
        which case they shall bear interest from August 1, 1993; provided,
        however, that, subject to the provisions of this Section with respect to
        failure by the Company to pay any interest on an interest payment date,
        the holder of any New Bond dated after a record date (as hereinafter
        defined) for the payment of interest and prior to the date of payment of
        such interest shall not be entitled to payment of such interest and
        shall have no claim against the Company with respect thereto.

           The person in whose name any New Bond is registered at the close of
        business on any record date with respect to any interest payment date
        shall be entitled to receive the interest payable on such interest
        payment date notwithstanding the cancellation of such Bond upon any
        transfer or exchange thereof subsequent to the record date and prior to
        such interest payment date, except if and to the extent the Company
        shall default in the payment of the interest due on such interest
        payment date, in which case such defaulted interest shall be paid to the
        person in whose name such Bond is registered on the date of payment of
        such defaulted interest or on a subsequent record date for such payment
        if one shall have been established as hereinafter provided.  A
        subsequent record date may be established by the Company by notice
        mailed to the holders of the New Bonds not less than ten days preceding
        such record date, which record date shall be not more than thirty days
        prior to the subsequent interest payment date.  The term "record date"
        as used in this Section with respect to any regular interest payment
        date shall mean the January 15 or July 15, as the case may be, next
        preceding such interest payment date, or, if such January 15 or

                                      -12-

 
        July 15 shall be a legal holiday in the State of New York or in the
        State of Missouri or a day on which banking institutions in the Borough
        of Manhattan, The City of New York, or the City of St. Louis, Missouri,
        are authorized by law to close, the next preceding day which shall not
        be a legal holiday or a day on which such institutions are so authorized
        to close.

           SECTION 3.  The New Bonds and the Trustee's certificate on the New
        Bonds shall be substantially in the following forms respectively:



                           [FORM OF FACE OF NEW BOND]
                             UNION ELECTRIC COMPANY
             (Incorporated under the laws of the State of Missouri)
                   First Mortgage Bond, 7.15% Series Due 2023
                               Due August 1, 2023
        No.                                                            $

           UNION ELECTRIC COMPANY, a corporation organized and existing under
        the laws of the State of Missouri (hereinafter called the "Company",
        which term shall include any successor corporation as defined in the
        Amended Indenture referred to on the reverse hereof), for value
        received, hereby promises to pay to ...................................
        ............................. or registered assigns, the sum of
        ..................................................................
        Dollars, on the first day of August 2023 in any coin or currency of the
        United States of America which at the time of payment is legal tender
        for public and private debts, and to pay interest thereon, in like coin
        or currency, at the rate of seven and fifteen one-hundredths per centum
        (7.15%) per annum, payable semi-annually, on February 1 and August 1 in
        each year until maturity, or, if the Company shall default in the
        payment of the principal hereof, until the Company's obligation with
        respect to the payment of such principal shall be discharged as provided
        in the Amended Indenture referred to on the reverse hereof.  Such
        interest shall be payable from the February 1 or August 1, as the case
        may be, next preceding the date hereof to which interest has not been
        paid, unless the date hereof is a February 1 or August 1 to which
        interest has been paid, in which case from the date hereof, or unless
        the date hereof is prior to the first payment of interest, in which case
        from August 1, 1993.  The interest so payable will be paid to the person
        in whose name this Bond, or the Bond in exchange or substitution for
        which this Bond shall have been issued, shall have been registered at
        the close of business on the January 15 or July 15, as the case may be,
        next preceding the date of payment, subject to certain exceptions set
        forth in the Amended Indenture.  The principal of, and interest and
        premium, if any, on, this Bond are payable at the office of the Company
        in the City of

                                      -13-

 
        St. Louis, Missouri; provided, however, that at the option of the
        Company, interest on this Bond may be paid by check mailed to the
        registered holder of this Bond at such holder's address as it shall
        appear on the books of the Company to be kept for that purpose.

           This Bond shall not be entitled to any benefit under the Amended
        Indenture or any indenture supplemental thereto, or become valid or
        obligatory for any purpose, until Boatmen's Trust Company, the Trustee
        under the Amended Indenture, or a successor trustee thereto under the
        Amended Indenture, or an agent therefor, shall have signed the form of
        certificate endorsed hereon.

           The provisions of this Bond are continued on the reverse hereof and
        such continued provisions shall for all purposes have the same effect as
        though fully set forth at this place.

           IN WITNESS WHEREOF, Union Electric Company has caused this Bond to be
        signed in its name by its Chairman of the Board or President or a Vice
        President by his manual signature or a facsimile thereof, and its
        corporate seal (or a facsimile thereof) to be hereto affixed and
        attested by its Secretary or an Assistant Secretary by his manual
        signature or a facsimile thereof.

           Dated,

                            Union Electric Company,

                                          By....................................

                                                             Vice President.
        [Corporate Seal]


        Attest:

        ..............................
                          Secretary.

                        [form of trustee's certificate]

           This Bond is one of the Bonds, of the series designated therein,
        described in the within-mentioned Amended Indenture and Supplemental
        Indenture of August 1, 1993.

                                    Boatmen's Trust Company,
                                    Trustee.

        By Union Electric Company, Agent

                                      -14-

 
                         [form of reverse of new bond]

           This Bond is one of a duly authorized issue of Bonds of the Company
        (herein called the "Bonds"), in unlimited aggregate principal amount, of
        the series hereinafter specified, all issued and to be issued under and
        equally secured by indenture of mortgage and deed of trust, dated June
        15, 1937, executed by the Company to Boatmen's Trust Company, (herein
        called the "Trustee"), as trustee, as amended by indentures supplemental
        thereto dated May 1, 1941, April 1, 1971, February 1, 1974, and July 7,
        1980, between the Company and the Trustee (said mortgage and deed of
        trust, as so amended, being herein called the "Amended Indenture"), to
        which Amended Indenture and all indentures supplemental thereto
        reference is hereby made for a description of the properties mortgaged
        and pledged, the nature and extent of the security, the rights of the
        bearers or registered owners of the Bonds and of the Trustee in respect
        thereto, and the terms and conditions upon which the Bonds are, and are
        to be, secured.  To the extent permitted by, and as provided in, the
        Amended Indenture, modifications or alterations of the Amended
        Indenture, or of any indenture supplemental thereto, and of the rights
        and obligations of the Company and of the holders of the Bonds may be
        made with the consent of the Company by an affirmative vote of not less
        than 80% in amount of the Bonds entitled to vote then outstanding, at a
        meeting of Bondholders called and held as provided in the Amended
        Indenture, and by an affirmative vote of not less than 80% in amount of
        the Bonds of any series entitled to vote then outstanding and affected
        by such modification or alteration, in case one or more but less than
        all of the series of Bonds then outstanding under the Amended Indenture
        are so affected.  The Company has reserved the right to amend the
        Amended Indenture without any consent or other action by holders of
        bonds of any series created by the Supplemental Indenture of August 16,
        1976, or by any supplemental indenture dated thereafter, including the
        Supplemental Indenture of August 1, 1993, to provide that the Amended
        Indenture may be modified or altered with the consent of the holders of
        not less than 60% in aggregate principal amount of the Bonds; and if
        less than all series of Bonds are affected with the consent also of the
        holders of not less than 60% in aggregate principal amount of the Bonds
        of each series so affected.  Additionally, the Company has reserved the
        right to amend the Amended Indenture, as supplemented, to authorize
        amendments thereto by an appropriate written consent of not less than
        60% in aggregate principal amount of the Bonds outstanding without a
        meeting of such Bondholders.  No such modification or alteration shall
        be made which will affect the terms of payment of the principal of, or
        interest or premium on, this Bond, which are unconditional.  The Bonds
        may be issued in series, for various principal sums, may mature at
        different times, may bear interest at different rates and may otherwise
        vary as in the Amended Indenture provided.  This Bond is one of a series
        designated as the "First Mortgage Bonds, 7.15% Series due 2023" (herein
        called the "Bonds of this Series") of the Company, issued under and
        secured by the Amended Indenture and described in the indenture
        (hereinafter called the

                                      -15-

 
        "New Supplemental Indenture") dated August 1, 1993, between the Company
        and the Trustee, supplemental to the Amended Indenture.

           The Bonds of this Series are not entitled to the benefit of any
        improvement, maintenance or analogous fund.

           The Bonds of this Series will be redeemable at the option of the
        Company, in whole or in part, at any time, upon the payment of
        redemption prices applicable to the respective periods set forth below;
        provided, however, that none of such Bonds shall be redeemed prior to
        August 1, 2003.



              12-Month                            12-Month
               Period              General          Period             General
              Beginning          Redemption       Beginning          Redemption
              August 1,          Price (%)        August 1,          Price (%)
              ---------         ------------      ---------         ------------
                                                           
 
              2003...........      103.01         2013...........      100.00
              2004...........      102.71         2014...........      100.00
              2005...........      102.41         2015...........      100.00
              2006...........      102.11         2016...........      100.00
              2007...........      101.81         2017...........      100.00
              2008...........      101.51         2018...........      100.00
              2009...........      101.21         2019...........      100.00
              2010...........      100.90         2020...........      100.00
              2011...........      100.60         2021...........      100.00
              2012...........      100.30         2022...........      100.00


        in each case, together with accrued interest to the date fixed for
        redemption.

           Such redemption in every case shall be effected upon notice sent by
        the Company to the registered owner hereof, postage prepaid, at least
        thirty and not more than sixty days prior to the date of redemption, all
        subject to the conditions of, and as more fully set forth in, the
        Amended Indenture and the New Supplemental Indenture.

           In case an event of default, as defined in the Amended Indenture,
        shall occur, the principal of all the Bonds at any such time outstanding
        under the Amended Indenture may be declared or may become due and
        payable, upon the conditions and in the manner and with the effect
        provided in the Amended Indenture.  The Amended Indenture provides that
        such declaration may in certain events be waived by the holders of a
        majority in principal amount of the Bonds outstanding.

           This Bond is transferable by the registered owner hereof, in person
        or by duly authorized attorney, on the books of the Company to be kept
        for that purpose at the office of the Company in the City of St. Louis,
        Missouri, upon surrender and cancellation of this Bond and on
        presentation of a duly executed written instrument of transfer, and
        thereupon a new Bond or Bonds of the same series, of the same aggregate
        principal amount and in authorized denominations will be issued to the
        transferee or transferees in exchange herefor, without

                                      -16-

 
        payment of any charge other than stamp taxes and other governmental
        charges incident thereto; and this Bond with or without others of like
        series, may in like manner be exchanged for one or more new Bonds of the
        same series of other authorized denominations but of the same aggregate
        principal amount; all subject to the terms and conditions set forth in
        the Amended Indenture.

           The Bonds of this Series are to be issued initially under a book-
        entry only system and, except as hereinafter provided, will be
        registered in the name of The Depository Trust Company, New York, New
        York ("DTC") or its nominee, which shall be considered to be the holder
        of all of the Bonds of this Series for all purposes of the Mortgage,
        including, without limitation, payment by the Company of principal of
        and interest on such Bonds of this Series and receipt of notices and
        exercise of rights of holders of such Bonds of this Series.  There shall
        be a single global bond of this series which shall be immobilized in the
        custody of DTC or its designee with the owners of book-entry interest in
        Bonds of this Series ("Book-Entry Interests") having no right to receive
        Bonds of this Series in the form of physical securities or certificates.
        Ownership of Book-Entry Interests shall be shown by book-entry on the
        system maintained and operated by DTC, its participants (the
        "Participants") and certain persons acting through the Participants.
        Transfers of ownership of Book-Entry Interests are to be made only by
        DTC and the Participants by that book-entry system, the Company and the
        Trustee having no responsibility therefor so long as Bonds of this
        Series are registered in the name of DTC or its nominee.  DTC is to
        maintain records of the positions of Participants in Bonds of this
        Series, and the Participants and persons acting through Participants are
        to maintain records of the purchasers and owners of Book-Entry
        Interests.  If DTC or its nominee determines not to continue to act as a
        depository for the Bonds of this Series in connection with a book-entry
        only system, another depository, if available, may act instead and the
        single global bond of this series will be transferred into the name of
        such other depository or its nominee, in which case the above provisions
        will continue to apply but to the new depository.  If the book-entry
        only system for Bonds of this Series is discontinued by the Company for
        any reason, upon surrender and cancellation of the single global bond of
        this series registered in the name of the then depository or its
        nominee, new registered Bonds of this Series will be issued in
        authorized denominations to the holders of Book-Entry Interests in
        principal amounts coinciding with the amounts of such Book-Entry
        Interests shown on the book-entry system immediately prior to the
        discontinuance thereof.  Neither the Trustee nor the Company shall be
        responsible for the accuracy of the interests shown on that system.

           No recourse shall be had for the payment of the principal of,
        premium, if any, on or the interest on, this Bond, or for any claim
        based hereon or on the Amended Indenture or any indenture supplemental
        thereto, against any incorporator, or against any stockholder, director
        or officer, past, present or future, of the Company, or of any
        predecessor or successor corporation, either directly or through the
        Company or any such predecessor or successor

                                      -17-

 
        corporation, whether for amounts unpaid on stock subscriptions or by
        virtue of any constitution, statute or rule of law, or by the
        enforcement of any assessment or penalty or otherwise, all such
        liability, whether at common law, in equity, by any constitution,
        statute or otherwise, of incorporators, stockholders, directors or
        officers being released by every owner hereof by the acceptance of this
        Bond and as part of the consideration for the issue hereof, and being
        likewise released by the terms of the Amended Indenture.

                      [end of form of reverse of new bond]



           SECTION 4.  Until New Bonds in definitive form are ready for
        delivery, the Company may execute, and upon its request in writing the
        Trustee shall authenticate and deliver, in lieu thereof, New Bonds in
        temporary form, as provided in Section 9 of Article II of the Original
        Indenture.  New Bonds in temporary form may, in lieu of the specific
        redemption prices, if any, required to be set forth in New Bonds in
        definitive form, include a reference to this Supplemental Indenture for
        a statement of such redemption prices.



                                  ARTICLE II.

                             ISSUE oF THE NEW BONDS

           SECTION 1.  The principal amount of the New Bonds which may be
        authenticated and delivered hereunder are not limited except as the
        Original Indenture limits the principal amount of Bonds which may be
        issued thereunder.

           SECTION 2.  The New Bonds in the aggregate principal amount of
        Seventy-Five Million Dollars ($75,000,000), being the initial issue of
        the New Bonds, may forthwith at any time or from time to time be
        executed by the Company and delivered to the Trustee and shall be
        authenticated by the Trustee and delivered (either before or after the
        filing or recording hereof) to or upon the order of the Company, upon
        compliance by the Company with the applicable provisions of Article III
        and Article XVIII of the Original Indenture.

                                      -18-

 
                                  ARTICLE III.

                          REDEMPTION OF THE NEW BONDS

           SECTION 1.  The New Bonds shall, subject to the provisions of Article
        V of the Original Indenture, be redeemable at any time or from time to
        time prior to maturity, at the option of the Board of Directors of the
        Company or pursuant to Section 8 of Article VIII of the Original
        Indenture, either as a whole or in part, at the then applicable
        redemption price set forth in the form of New Bonds in Section 3 of
        Article I of this Supplemental Indenture, together, in each case, with
        accrued interest to the redemption date.

           In case of the redemption of less than all the outstanding New Bonds,
        the particular New Bonds or portions (equal to $1,000 or an integral
        multiple thereof) of the New Bonds of a denomination larger than $1,000
        to be redeemed shall be determined by lot in such manner as the Trustee
        in its discretion shall deem proper, as in the Original Indenture
        provided.

           Irrespective of the provisions of this Section 1, the New Bonds shall
        not be redeemable at the option of the Company at any time prior to
        August 1, 2003.

           There shall be no improvement, maintenance or analogous fund for the
        New Bonds.

           SECTION 2.  Subject to the provisions of Article V of the Original
        Indenture, notice of redemption shall be delivered by the Company at
        least thirty and not more than sixty days prior to the date of
        redemption, to the registered owners of the New Bonds to be redeemed at
        their addresses as they appear on the transfer register of the Company,
        except that failure to so mail a notice shall not affect the validity of
        the proceedings for redemption of any other New Bonds.



                                  ARTICLE IV.

                                   COVENANTS.

           The Company hereby covenants, warrants and agrees;

           SECTION 1.  That the Company is lawfully seized and possessed of all
        of the mortgaged property described in the granting clauses of this
        Supplemental Indenture; that it has good right and lawful authority to
        mortgage the same as provided in this Supplemental Indenture; and that
        such mortgaged property is, at

                                      -19-

 
        the actual date of the issue of the New Bonds, free and clear of any
        deed of trust, mortgage, lien, charge or encumbrance thereon or
        affecting the title thereto prior to the Original Indenture, except as
        set forth in the granting clauses of the Original Indenture or this
        Supplemental Indenture.

           SECTION 2.  That, so long as any of the New Bonds are outstanding,
        whenever any officers' certificate is required to be filed or deposited
        with the Trustee pursuant to Section 3(b) of Article III of the Original
        Indenture upon an application for the authentication of additional Bonds
        pursuant to Article III of the Original Indenture, such officers'
        certificate shall include, in addition to the matters required to be
        stated therein by said Section 3(b), the statement with respect to the
        net earnings of the Company available for interest after property
        retirement appropriations required by Section 2 of Article V of the
        Supplemental Indenture of July 1, 1956.

           SECTION 3.  That, so long as any of the New Bonds are outstanding,
        the Company will not apply for the authentication and delivery of
        additional Bonds pursuant to Section 4 of Article III of the Original
        Indenture or the withdrawal of cash from the trust estate or the
        reduction of the amount of cash required to be paid into the trust
        estate or to satisfy the maintenance and improvement funds under any
        provision of the Original Indenture or the Supplemental Indentures
        creating prior series of Bonds, on the basis of the amount of
        $15,000,000 excluded from net bondable value of property additions not
        subject to an unfunded prior lien pursuant to Section 3 of Article V of
        the Supplemental Indenture of October 1, 1945, or on the basis of the
        amount of $7,500,000 excluded from net bondable value of property
        additions not subject to an unfunded prior lien pursuant to Section 3 of
        Article V of the Supplemental Indenture of July 1, 1956.

           SECTION 4.  That, so long as any of the New Bonds are outstanding,
        the Company will not issue or permit to be issued any prior lien bonds
        secured by an unfunded prior lien in addition to the prior lien bonds
        secured by such unfunded prior lien at the time of first acquisition by
        the Company of property subject thereto (other than in lieu of lost,
        stolen or mutilated bonds or on the exchange for bonds already
        outstanding of an equal principal amount of other bonds of the same
        issue and the same series, if any, and of the same maturity), except
        upon compliance with the provisions of Section 16 of Article IV of the
        Original Indenture, nor unless the net earnings of the Company available
        for interest after property retirement appropriations (determined as
        provided in Section 2 of Article V of the Supplemental Indenture of July
        1, 1956), for any twelve consecutive calendar months during the period
        of fifteen calendar months immediately preceding the first day of the
        month in which the additional prior lien bonds are to be issued, have
        been, in the aggregate, equal to not less than

                                      -20-

 
        twice the annual interest charges on the indebtedness specified in
        subparagraphs (i) and (ii) of paragraph (1) of Section 2(a) of said
        Article V; provided that, if the application for the issue of such
        additional prior lien bonds is upon the basis of payment at maturity of
        prior lien bonds theretofore sold or otherwise disposed of or the
        redemption or purchase thereof after a date two years prior to the date
        of maturity, the additional requirement imposed by this Section 4 with
        respect to net earnings of the Company available for interest after
        property retirement appropriations shall not apply.  Any officers'
        certificate with respect to net earnings of the Company, required to be
        filed with the Trustee as a condition precedent to the issue of such
        additional prior lien bonds, shall include, in addition to the matters
        otherwise required to be stated therein, the matters required to be
        stated in an officers' certificate pursuant to paragraphs (1) and (2) of
        Section 2(a) of said Article V.

           SECTION 5.  That, so long as any of the New Bonds are outstanding,
        the Company will not acquire, by purchase, merger or otherwise, any
        property subject to a lien or liens which will on acquisition be an
        unfunded prior lien or prior liens, except upon compliance with the
        provisions of Section 14 of Article IV of the Original Indenture, nor
        unless the net earnings of such property available for interest after
        property retirement appropriations (determined in the manner provided in
        Section 2 of Article V of the Supplemental Indenture of July 1, 1956),
        for any twelve consecutive calendar months during the period of fifteen
        calendar months immediately preceding the first day of the month in
        which the first acquisition of property subject to such lien or liens
        occurs, have been, in the aggregate, equal to not less than twice the
        amount of annual interest charges, on all outstanding indebtedness
        secured by such lien or liens.  Any officers' certificate with respect
        to net earnings of such property, required to be filed with the Trustee
        as a condition precedent to the acquisition of such property, shall
        include, in addition to the matters otherwise required to be stated
        therein, the matters required to be stated in an officers' certificate
        pursuant to Section 2 of said Article V applicable, however, only to the
        net earnings of such property and to the indebtedness secured by such
        liens to which such property is subject.



                                   ARTICLE V.

                                  THE TRUSTEE.

           The Trustee hereby accepts the trusts hereby declared and provided,
        and agrees to perform the same upon the terms and conditions in the
        Original Indenture and in this Supplemental Indenture set forth, and
        upon the following terms and conditions:

                                      -21-

 
           The Trustee shall not be responsible in any manner whatsoever for or
        in respect of the validity or sufficiency of this Supplemental Indenture
        or the due execution hereof by the Company or for or in respect of the
        recitals contained herein, all of which recitals are made by the Company
        solely.



                                  ARTICLE VI.

              CONSENTS AND AGREEMENTS OF HOLDERS OF THE NEW BONDS
                               TO CERTAIN MATTERS

           The Company, and the holders of the New Bonds by their acceptance and
        holding thereof, hereby consent and agree as follows:

              (A)  When the provisions of this Article VI shall become effective
           as provided in Subdivision (B) hereof, the provisions of the Original
           Indenture shall become and shall be deemed to have been, amended,
           effective on said date, by the Supplemental Indenture dated February
           1, 1974, in the following respects:

           (1) by inserting the following paragraph after the definition of
        "Nonbondable property" in Article I of the Original Indenture;

           "Nuclear fuel:

              The term 'Nuclear fuel' shall mean (a) any fuel element, including
           nuclear fuel and associated means (and any similar or analogous
           device or substance), whether or not classified as fuel and whether
           or not chargeable to operating expenses, comprising or intended to
           comprise or formerly comprising the core, or other part of a nuclear
           reactor or any similar or analogous device, (b) any fuel element,
           including nuclear fuel and associated means (and any similar or
           analogous device or substance) while in the process of fabrication or
           preparation and special nuclear or other materials held for use in
           such fabrication or preparation, (c) any substances or materials
           formerly comprising such nuclear fuel and associated means (or any
           similar or analogous device or substance) and which substances or
           materials are undergoing or have undergone reprocessing and (d)
           uranium, thorium, plutonium, and any other substance or material from
           time to time used or selected for use by the Company as fuel
           material, or as potential fuel material, in a nuclear reactor or any
           similar or analogous device."

                                      -22-

 
           (2)  by deleting the word "and" at the end of subparagraph (e) of the
        definition of "Permitted liens" in Article I of the Original Indenture,
        changing the period at the end of subparagraph (f) of such definition to
        "; and", and adding a new subparagraph (g) reading as follows:

              "(g) any controls, liens, restrictions, regulations, easements,
           exceptions or reservations of any governmental authority applying
           particularly to 'Nuclear fuel'."

           (3) by deleting the word "and" at the end of subparagraph (d) of the
        third paragraph of the definition of "Property additions" in Article I
        of the Original Indenture, changing the period at the end of
        subparagraph (e) to "; and" and adding a new subparagraph (f) reading as
        follows:

              "(f) anything in this Indenture notwithstanding, the term
           'Property additions' shall include 'Nuclear fuel'."

           (4) by inserting after the words "such property additions" when first
        used in subdivision (4) of subparagraph (f) of Section 4 of Article III
        of the Original Indenture the following:

                ", provided that, in the case of property additions constituting
              all or part of a facility for the production of electricity by use
              of a nuclear reactor or any similar or analogous device, or
              Nuclear fuel materials, assemblies or components for use therein,
              in respect of which the application is made prior to receipt of
              necessary authority to operate such facility, such opinion need
              only state that (i) the Company has necessary authority to own
              such property additions and (ii) in the case of property additions
              for which construction authority is necessary, the Company has
              necessary authority to construct the same."

        and

           (5) by inserting after the words "any machinery or equipment," in
        subparagraph (a) of Section 2 of Article VII of the Original Indenture
        the following:

              "or any Nuclear fuel materials, assemblies or components,"

               (B)  The provisions of this Article VI shall become effective on
             the earliest date on which either (a) no Bonds of a Series prior to
             the Bonds of 2004 Series (as described in the Supplemental
             Indenture dated February 1, 1974) shall be outstanding or (b) the
             amendment to the Original Indenture provided in Article VII of the
             Supplemental Indenture dated February 1,

                                      -23-

 
           1974, shall have become effective upon vote of the holders of Bonds
           as provided in Article XV of the Original Indenture, provided that no
           vote of the holders of the Bonds of 2004 Series or Bonds of any
           series created thereafter shall be required for effecting such
           amendments.



                                  ARTICLE VII.

                           RESERVATIONS BY COMPANY TO
                           AMEND ORIGINAL INDENTURE.

           SECTION 1.  The Company reserves the right, subject to appropriate
        corporate action, but without any consent or other action by holders of
        Bonds of any series created by the Supplemental Indenture of August 16,
        1976, or by any supplemental indenture dated thereafter, including this
        Supplemental Indenture, to make such amendments to the Original
        Indenture, as supplemented, as shall be necessary in order to amend
        Article XV thereof so as to substitute "sixty percent. (60%)" for
        "eighty percent. (80%)" wherever appearing in said Article XV.

           SECTION 2.  The Company reserves the right, subject to appropriate
        corporate action, but without any consent or other action by holders of
        Bonds of any series created by the Supplemental Indenture of August 16,
        1976, or by any supplemental indenture dated thereafter, including this
        Supplemental Indenture, to make such amendments to the Original
        Indenture, as supplemented, as shall be necessary in order to amend
        Article XV thereof by adding thereto a Section 9 to read as follows:

               "SECTION 9.  (A)  Anything in this Article XV contained to the
             contrary notwithstanding, the Trustee shall receive the written
             consent (in any number of instruments of similar tenor executed by
             Bondholders or by their attorneys appointed in writing) of the
             holders of sixty percent. (60%) or more in principal amount of the
             Bonds outstanding hereunder, and, if the rights of one or more, but
             less than all, series of Bonds then outstanding are to be affected
             by action taken pursuant to such consent, then also by consent of
             the holders of at least sixty per cent. (60%) in principal amount
             of each  series of Bonds so to be affected and outstanding
             hereunder (at the time the last such needed consent is delivered to
             the Trustee) in lieu of the holding of a meeting pursuant to this
             Article XV and in lieu of all action at such a meeting and with the
             same force and effect as a resolution duly adopted in accordance
             with the provisions of Section 6 of this Article XV.

                                      -24-

 
              (B)  Instruments of consent shall be witnessed or in the
           alternative may (a) have the signature guaranteed by a bank or trust
           company or a registered dealer in securities, (b) be acknowledged
           before a Notary Public or other officer authorized to take
           acknowledgements, or (c) have their genuineness otherwise established
           to the satisfaction of the Trustee.

              The amount of Bonds payable to bearer, and the series and serial
           numbers thereof, held by a person executing an instrument of consent
           (or whose attorney has executed an instrument of consent in his
           behalf), and the date of his holding the same may be proved by
           exhibiting the Bonds to and obtaining a certificate executed by (i)
           any bank or trust or insurance company, or (ii) any trustee,
           secretary, administrator or other proper officer of any pension,
           welfare, hospitalization or similar fund or funds, or (iii) the
           United States of America, any Territory thereof, the District of
           Columbia, any State of the United States or any public
           instrumentality of the United States, or of any State or of any
           Territory, or (iv) any other person or corporation satisfactory to
           the Trustee.  A Bondholder in any of the foregoing categories may
           sign a certificate in his own behalf.

              Each such certificate shall be dated and shall state, in effect,
           that as of the date thereof, a coupon Bond or Bonds bearing a
           specified serial number or numbers was deposited with or exhibited to
           the signer of such certificate.  The holding by the person named in
           any such certificate of any Bond specified therein shall be presumed
           to continue unless (1) any certificate bearing a later date issued in
           respect of the same Bond shall be produced, (2)  the Bond specified
           in such certificate (or any Bond or Bonds issued in exchange or
           substitution for such Bond) shall be produced by another holder, or
           (3) the Bond specified in such certificate shall be registered as to
           principal in the name of another holder or shall have been
           surrendered in exchange for a fully registered bond registered in the
           name of another holder.  The Trustee may nevertheless, in his
           discretion, require further proof in cases where it deems further
           proof desirable.  The ownership of registered Bonds shall be proved
           by the registry books.

               (C)  Until such time as the Trustee shall receive the written
             consent of the necessary per cent. in principal amount of the Bonds
             required by the provisions of subsection (A) above for action
             contemplated by such consent, any holder of a Bond, the serial
             number of which is shown by the evidence to be included in the
             Bonds the holders of which have consented to such action, may, by
             filing written notice with the Trustee at its principal office and
             upon proof of holding as provided in subsection (B) above, revoke
             such consent so far as it concerns such Bond.  Except as aforesaid,
             any such action taken by the holder of any Bond shall be conclusive
             and binding upon

                                      -25-

 
           such holder and upon all future holders of such Bond (and any Bond
           issued in lieu thereof or exchanged therefor), irrespective of
           whether or not any notation of such consent is made upon such Bond,
           and in any event any action taken by the holders of the percentage in
           aggregate principal amount of the Bonds specified in subsection (A)
           above in connection with such action shall be conclusively binding
           upon the Company, the Trustee and the holders of all the Bonds."



                                 ARTICLE VIII.

                           MISCELLANEOUS PROVISIONS.

           SECTION 1.  Except as otherwise defined herein, all terms contained
        in this Supplemental Indenture shall, for all purposes thereof, have the
        meanings given to such terms in Article I of the Original Indenture.

           SECTION 2.  This Supplemental Indenture may be simultaneously
        executed in any number of counterparts, each of which when so executed
        shall be deemed to be an original; but such counterparts shall together
        constitute but one and the same instrument.

           IN WITNESS WHEREOF, said Union Electric Company has caused this
        Supplemental Indenture to be executed on its behalf by its Chairman of
        the Board or President or one of its Vice Presidents and its corporate
        seal to be hereto affixed and said seal and this Supplemental Indenture
        to be attested by its Secretary or one of its Assistant Secretaries; and
        said Boatmen's Trust Company, in evidence of its acceptance of the trust
        hereby created, has caused this Supplemental Indenture to be executed on
        its behalf by its President or one of its Vice Presidents, and its
        corporate seal to be hereto affixed and said seal and

                                      -26-

 
        this Supplemental Indenture to be attested by its Secretary, or one of
        its Assistant Secretaries; all as of the 1st day of August, One thousand
        nine hundred and ninety-three.

                               UNION ELECTRIC COMPANY,
                                 1901 Chouteau Avenue
        [Corporate Seal]         St. Louis, Missouri.

                               By  Donald E. Brandt
        Attested:                   Senior Vice President.


         James C. Thompson
               Secretary.


        Signed, sealed and delivered by
         UNION ELECTRIC COMPANY
         in the presence of:

         Mark E. Blair

         G. L. Waters

               As Witnesses.

                               BOATMEN'S TRUST COMPANY,
                                  510 Locust Street,
        [Corporate Seal]          St. Louis, Missouri.

                               By  H. E. Bradford
        Attested:                   Senior Vice President.

         Jerry L. Rector
                 Assistant Secretary.


        Signed, sealed and delivered by
         BOATMEN'S TRUST COMPANY
         in the presence of:

         Lisa A. Godiner

         P. C. QuiBelle

                               As Witnesses.

                                      -27-

 
        STATE OF MISSOURI,  }
                            }  SS.:
        CITY OF ST. LOUIS,  }

           On this 4th day of August, 1993, before me appeared DONALD E. BRANDT,
        to me personally known, who, being by me duly sworn, did say that he is
        a Senior Vice President of UNION ELECTRIC COMPANY, a corporation, and
        that the seal affixed to the foregoing instrument is the corporate seal
        of said corporation, and that said instrument was signed and sealed in
        behalf of said corporation by authority of its Board of Directors, and
        said DONALD E. BRANDT acknowledged said instrument to be the free act
        and deed of said corporation.

           IN TESTIMONY WHEREOF, I have hereto set my hand and affixed my
        official seal at my office, in the City and State aforesaid, the day and
        year last above written.

        [Notarial Seal]

                                                Barbara Lungwitz
                                       ----------------------------------- 
                                                BARBARA LUNGWITZ
                                        NOTARY PUBLIC - STATE OF MISSOURI
                                       MY COMMISSION EXPIRES SEPT. 2, 1995
                                               CITY OF ST. LOUIS



        STATE OF MISSOURI,  }
                            }  SS.:
        CITY OF ST. LOUIS,  }

           On this 4th day of August, 1993, before me appeared H. E. BRADFORD,
        to me personally known, who, being by me duly sworn, did say that he is
        a Senior Vice President of BOATMEN'S TRUST COMPANY, a corporation, and
        that the seal affixed to the foregoing instrument is the corporate seal
        of said corporation, and that said instrument was signed and sealed in
        behalf of said corporation, as the trustee thereunder by authority of
        its Board of Directors, and said H. E. BRADFORD, acknowledged said
        instrument to be the free act and deed of said corporation as the
        trustee under said instrument.

           IN TESTIMONY WHEREOF, I have hereto set my hand and affixed my
        official seal at my office, in the City and State aforesaid, the day and
        year last above written.

        [Notarial Seal]
                                                Barbara Lungwitz
                                       ----------------------------------- 
                                                BARBARA LUNGWITZ
                                        NOTARY PUBLIC - STATE OF MISSOURI
                                       MY COMMISSION EXPIRES SEPT. 2, 1995
                                               CITY OF ST. LOUIS

                                      -28-