EXHIBIT 4(A)
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                       BALTIMORE GAS AND ELECTRIC COMPANY
                                       TO
                         BANKERS TRUST COMPANY, TRUSTEE

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                             SUPPLEMENTAL INDENTURE
               SUPPLEMENTING DEED OF TRUST DATED FEBRUARY 1, 1919
                             ---------------------

                                   TO SECURE
                                  $125,000,000
                    FLOATING RATE SERIES DUE APRIL 15, 1999
                         FIRST REFUNDING MORTGAGE BONDS

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SUPPLEMENTAL  INDENTURE,  made as  of the  fifteenth  day of  March in  the year
nineteen hundred and  ninety-four, for convenience  of reference, and  effective
from the time of execution and delivery hereof, by and between BALTIMORE GAS AND
ELECTRIC  COMPANY (name changed  from CONSOLIDATED GAS  ELECTRIC LIGHT AND POWER
COMPANY OF BALTIMORE on April 4, 1955), a corporation duly created and organized
under the law of the State of Maryland, hereinafter called the "Company,"  party
of  the first part,  and BANKERS TRUST  COMPANY, a corporation  duly created and
organized under the law of  the State of New  York, having its principal  office
and  place of business at Four Albany  Street, Borough of Manhattan, The City of
New York, hereinafter called the "Trustee," party of the second part.

    WHEREAS, The Company heretofore duly executed, acknowledged and delivered to
the Trustee (a) an indenture of mortgage or deed of trust dated February 1, 1919
(which as amended and/or supplemented by the seventy-two supplemental indentures
hereinafter mentioned, is hereinafter called the "Refunding Mortgage"), recorded
among the Land Records  or Mortgage Records  (as the case  may be) of  Baltimore
City,  Baltimore  County, Howard  County, Anne  Arundel County,  Carroll County,
Harford County, Montgomery County, Prince George's County, Calvert County, Cecil
County, and Frederick County, Maryland, and indexed among the Chattel Records of
Baltimore City and each of the  counties aforesaid except Frederick County;  (b)
twenty-six  successive  indentures supplemental  to and  forming  a part  of the
Refunding Mortgage, dated respectively as of December 1, 1920, October 1,  1921,
September  1, 1922,  June 1, 1925,  March 1, 1929,  July 1, 1930,  June 1, 1931,
November 1, 1934, May 1,  1935, July 1, 1935, December  1, 1936, June 15,  1938,
June  1, 1939, January 1, 1941, April 1, 1946, March 1, 1948, December 19, 1949,
December 20, 1949, June 15, 1950, January 15, 1951, June 1, 1953, July 15, 1954,
December 1, 1955, March 1, 1958, June 1, 1960, and July 15, 1962, each  recorded
among  the Land Records  or Mortgage Records  (as the case  may be) of Baltimore
City and the counties aforesaid,  and recorded or indexed  (as the case may  be)
among  the Chattel Records  of Baltimore City and  the counties aforesaid except
Frederick County; (c) forty-four indentures  supplemental to and forming a  part
of  the Refunding Mortgage, dated as of July 15, 1964, April 15, 1966, August 1,
1967, December  15, 1968,  September 15,  1969,  April 1,  1970, July  1,  1970,
September  15, 1970, April 15, 1971, September 1, 1971, January 1, 1972, July 1,
1972, September  15, 1972,  August 15,  1973, February  1, 1974,  July 1,  1974,
September  15, 1974, August  1, 1975, September  15, 1976, July  15, 1977 (three
supplemental indentures), September 15, 1977,  July 1, 1978, September 15,  1979
(two  supplemental indentures),  September 15,  1980, July  8, 1981,  October 1,
1981, July 15, 1982, March 1, 1986, June 15, 1987, October 15, 1989, October 15,
1990, August 15, 1991, January 15, 1992, July 1, 1992, February 15, 1993,  March
1,  1993, March  15, 1993,  April 15,  1993, July  1, 1993,  July 15,  1993, and
October 15, 1993, and each recorded among the Land Records of Baltimore City and
the counties aforesaid (with respect  to personal property and fixtures  located
in  Maryland now  owned or hereafter  acquired by  the Company, the  lien of the
Refunding Mortgage has been perfected as a security interest under the  Maryland
Uniform  Commercial Code, by recording and indexing a financing statement in the
office of the Maryland  State Department of Assessments  and Taxation); (d)  the
aforesaid indenture of mortgage or deed of trust dated February 1, 1919, and the
following indentures supplemental thereto dated as of December 1, 1920, November
1,  1934,  December 1,  1936, June  15, 1938,  January 1,  1941, April  1, 1946,
December 19, 1949, December 20, 1949, June 15, 1950, January 15, 1951, July  15,
1954,  December 1, 1955,  March 1, 1958, June  1, 1960, July  15, 1962, July 15,
1964, April 15,  1966, August 1,  1967, December 15,  1968, September 15,  1969,
April  1, 1970, July 1,  1970, September 15, 1970,  April 15, 1971, September 1,
1971, January  1, 1972,  July 1,  1972,  September 15,  1972, August  15,  1973,
February  1, 1974, July 1,  1974, September 15, 1974,  August 1, 1975, September
15, 1976, July  15, 1977  (three supplemental indentures),  September 15,  1977,
July  1, 1978, September  15, 1979 (two  supplemental indentures), September 15,
1980, July 8,  1981, October 1,  1981, July 15,  1982, March 1,  1986, June  15,
1987,  October 15, 1989,  October 15, 1990,  August 15, 1991,  January 15, 1992,
July 1, 1992, February 15, 1993, March 1, 1993, March 15, 1993, April 15,  1993,
July  1, 1993, July 15,  1993, and October 15, 1993,  have been duly recorded in
mortgage books in the respective  offices of the Recorders  of Deeds in and  for
Adams  County, Armstrong County,  Bedford County, Blair  County, Cambria County,
Cumberland  County,  Franklin   County,  Huntingdon   County,  Indiana   County,
Montgomery  County, Westmoreland County, and  York County, Pennsylvania; (e) and
also Supplemental Indentures  dated July 26,  1965 and June  16, 1967 have  been
duly  recorded in mortgage books  in the respective offices  of the Recorders of
Deeds in  and for  Armstrong and  Indiana Counties,  Pennsylvania; and  (f)  the
aforesaid  indenture of mortgage or deed of trust dated February 1, 1919 and the
following supplemental indentures thereto dated as of December 1, 1920, November
1, 1934,  December 1,  1936, June  15, 1938,  January 1,  1941, April  1,  1946,
December 19, 1949, March 1, 1958, July 15, 1964, April 15, 1966, August 1, 1967,
December  15, 1968, April 1, 1970, April 15, 1971, September 1, 1971, January 1,
1972, July  1, 1972,  September 15,  1972, August  15, 1973,  February 1,  1974,
September 15, 1976, July 15, 1977 (three supplemental indentures), September 15,
1977,  July 1, 1978, September 15,  1979 (two supplemental indentures), March 1,
1986, June  15, 1987,  October 15,  1989,  October 15,  1990, August  15,  1991,
January  15, 1992,  July 1, 1992,  February 15,  1993, March 1,  1993, March 15,
1993, April 15, 1993, July  1, 1993, July 15, 1993,  and October 15, 1993,  have
been  duly recorded in the mortgage books in the office of the Recorder of Deeds
in and for Montgomery  County, Pennsylvania (with  respect to personal  property
and  fixtures located  in Pennsylvania, now  owned or hereafter  acquired by the
Company, the

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lien of the Refunding Mortgage has  been perfected as a security interest  under
the  Pennsylvania Uniform Commercial Code by filing a financing statement in the
office  of  the   Secretary  of   the  Commonwealth  of   the  Commonwealth   of
Pennsylvania);  which Refunding Mortgage  is hereby referred to  and made a part
hereof as fully as  if herein recited at  length, and the several  corporations,
mortgages  or deeds  of trust, indentures,  bonds, notes,  securities and stocks
referred to  in  the  Refunding  Mortgage are,  when  hereinafter  referred  to,
sometimes  referred to by the  short names by which they  are referred to in the
Refunding Mortgage, and  the several words,  terms and expressions  particularly
defined  or construed in  the Refunding Mortgage,  in Section 4  or Section 5 of
Article XI thereof or  elsewhere, when used in  this supplemental indenture  are
used as so defined or construed in the Refunding Mortgage; and

    WHEREAS,  By the  Refunding Mortgage it  is among other  things provided, in
Section 9 of  Article III  thereof, that  from time  to time  the Company,  when
authorized  by a  resolution of  its Board  of Directors,  and the  Trustee may,
subject to the provisions  of the Refunding  Mortgage, execute, acknowledge  and
deliver  indentures  supplemental thereto,  which thereafter  shall form  a part
thereof, for the purpose (among others) of conveying, assuring or confirming to,
or vesting in, the Trustee additional  property now owned or hereafter  acquired
pursuant  to Section 7 of Article I or Section 2 of Article III of the Refunding
Mortgage, adding to the covenants of  the Company in the Refunding Mortgage  for
the  protection  of the  holders of  the Securities,  making provisions  for the
redemption before maturity of any bonds  thereafter to be issued thereunder,  or
making  such provision, not inconsistent with  the Refunding Mortgage, as may be
necessary or desirable with respect to matters or questions arising  thereunder;
and

    WHEREAS,  The Company  has determined  to issue  additional bonds  under and
pursuant to  the provisions  of the  Refunding Mortgage  and has  determined  to
execute,  acknowledge and deliver this  indenture, supplemental to the Refunding
Mortgage and hereafter  to form a  part thereof, for  the purpose of  conveying,
assuring  or confirming to,  or vesting in, the  Trustee additional property now
owned or hereafter acquired pursuant to Section  7 of Article I or Section 2  of
Article III of the Refunding Mortgage, adding to the covenants of the Company in
the  Refunding Mortgage  for the  protection of  the holders  of the Securities,
making provisions for the  redemption before maturity of  bonds hereafter to  be
issued under the Refunding Mortgage, and making such provision, not inconsistent
with  the Refunding Mortgage, as  may be necessary or  desirable with respect to
matters or questions  arising thereunder, and  the Company and  the Trustee  are
willing  so to execute, acknowledge and  deliver this supplemental indenture for
the purposes aforesaid; and

    WHEREAS, At meetings of  the Board of Directors  of the Company duly  called
and  held as provided by  law on the seventeenth day  of September, 1993 and the
eighteenth day of February, 1994,  at which meetings a  quorum of said Board  of
Directors  was present and voted, this supplemental indenture was then and there
submitted to  the  said  Board  of Directors  and  resolutions  authorizing  the
execution,  acknowledgment and delivery  of this supplemental  indenture and the
issuance, certification and delivery of First Refunding Mortgage Bonds under and
pursuant to the provisions of the Refunding Mortgage, as so supplemented by this
supplemental indenture, were unanimously adopted by the affirmative vote of  all
the members so present.

    NOW,  THEREFORE, THIS SUPPLEMENTAL  INDENTURE WITNESSETH: That,  in order to
secure the payment of  the principal of  and interest on all  such bonds at  any
time  issued and  outstanding under the  Refunding Mortgage,  according to their
tenor and  effect,  and to  secure  the performance  of  all the  covenants  and
conditions   contained  in  the  Refunding  Mortgage  as  supplemented  by  this
supplemental indenture, and to declare the terms and conditions upon which  said
bonds  are issued, or  to be issued,  and secured under  the Refunding Mortgage,
Baltimore  Gas  and  Electric  Company,  the   party  of  the  first  part,   in
consideration  of the premises and of the  purchase of such bonds by the holders
thereof, and of  the sum of  one dollar, lawful  money of the  United States  of
America,  to it duly paid by the Trustee at or before the ensealing and delivery
of these presents, the receipt whereof is hereby acknowledged, has executed  and
delivered  these  presents  and  hereby  ratifies,  approves  and  confirms  the
Refunding Mortgage in  all respects as  fully as if  all the terms,  provisions,
covenants  and  conditions thereof  were herein  again set  forth at  length, as
supplemented hereby,  and  has  granted, bargained,  sold,  released,  conveyed,
assigned, transferred, mortgaged, pledged, set over and confirmed, and granted a
security  interest therein,  and by  these presents  does grant,  bargain, sell,
release, convey, assign, transfer, mortgage,  pledge, set over and confirm,  and
grant  a  security interest  therein unto  Bankers Trust  Company, party  of the
second part, and unto its successors  and assigns forever, all and singular  the
premises,  property and franchises of the Company  other than as excepted in the
Refunding Mortgage, now owned or hereafter acquired in Maryland or Pennsylvania.

    TOGETHER with all the  rights, privileges and appurtenances  to any of  said
premises,  property and franchises belonging or in anywise appertaining, and the
reversion and reversions,  remainder and remainders,  rents, issues, income  and
profits thereof, and all the estate, right, title and interest which the Company
now  has  or may  hereafter acquire  therein or  thereto  or in  or to  any part
thereof.

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    TO HAVE  AND TO  HOLD, All  and  singular the  said premises,  property  and
franchises,  appurtenances, rents,  issues, income and  profits hereby conveyed,
transferred, assigned and confirmed, or intended so to be, unto the Trustee, its
successors and assigns, forever.

    IN TRUST, NEVERTHELESS, For the equal and proportionate benefit and security
of all holders  of the bonds  and interest  obligations issued or  to be  issued
under  the Refunding Mortgage,  and for the  enforcement of the  payment of said
bonds  and  interest  obligations  when  payable  and  the  performance  of  and
compliance  with  the  covenants and  conditions  of the  Refunding  Mortgage as
supplemented by  this supplemental  indenture, without  preference, priority  or
distinction,  as to  lien or  otherwise of  any series  of bonds  over any other
series of bonds, or of any one bond over any other bonds, by reason of  priority
in  the issue or negotiation  thereof or otherwise, so  that each and every bond
issued or to  be issued under  the Refunding Mortgage  or secured thereby  shall
have  the  same  right,  lien  and privilege  under  the  Refunding  Mortgage as
supplemented by  this supplemental  indenture,  and so  that the  principal  and
interest  of every such bond, subject to  the terms of the Refunding Mortgage as
so supplemented, be equally  and proportionately secured thereby  as if all  had
been duly made, executed, delivered, sold and negotiated simultaneously with the
execution  and delivery  of the Refunding  Mortgage, it being  intended that the
lien and security of the Refunding Mortgage  shall take effect from the date  of
the  execution and delivery  thereof without regard  to the time  of such actual
issue, sale or disposition of  said bonds, and as though  upon said date all  of
said  bonds had  been actually issued,  sold and  delivered to, and  were in the
hands of, holders thereof for value.

    AND IT IS HEREBY  FURTHER COVENANTED AND DECLARED,  That all such bonds  are
issued and certified and delivered, or to be issued and certified and delivered,
and  the mortgaged premises and property are  to be held by the Trustee, subject
to the further covenants, conditions, uses and trusts in the Refunding Mortgage,
as supplemented by this supplemental indenture, set forth, and it is agreed  and
covenanted  by the Company with the Trustee and the respective holders from time
to time of bonds issued under the Refunding Mortgage as follows, viz:

    1.   As  supplemented  hereby,  each  and  all  of  the  terms,  provisions,
covenants,  conditions,  uses  and  trusts  set forth  in  that  portion  of the
Refunding Mortgage beginning with and including the words "Article I. Issue  and
Appropriation of Bonds," and continuing to the end of the Refunding Mortgage, as
supplemented  and amended by the  seventy-two successive supplemental indentures
herein above mentioned, are hereby  expressly ratified, approved and  confirmed,
as fully and with the same force and effect as if the same were herein again set
forth  at  length, provided,  however, that  no  provision of  this Supplemental
Indenture is  intended to  reinstate any  provisions in  the Refunding  Mortgage
which  were amended and superseded by the  amendments to the Trust Indenture Act
of 1939 effective as of November 15, 1990.

    2.  One  series of bonds  to be issued  under and secured  by the  Refunding
Mortgage  shall be designated as Floating Rate  Series due April 15, 1999, First
Refunding Mortgage Bonds (hereinafter called "bonds of the Designated  Series").
Bonds  of the  Designated Series  shall be  issued only  as registered  bonds in
denominations of  one  thousand dollars  and  multiples thereof.  Bonds  of  the
Designated  Series may  be exchanged  for a  like aggregate  principal amount of
bonds of  the  Designated  Series  of other  denominations.  Each  bond  of  the
Designated  Series shall be  dated the date of  its authentication, shall mature
April 15, 1999, shall be payable as to principal and interest in lawful money of
the United  States of  America which  shall be  legal tender  at the  time  such
payment  becomes due, at the  principal office of Bankers  Trust Company (or its
successor in trust), in the Borough of Manhattan, in The City of New York, or at
such other institutions as  designated by the  Company, provided, however,  that
each  installment  of  interest  may  be paid  by  mailing  checks,  or  by wire
transfers, for such interest payable to the order of the person entitled thereto
to the registered  address of  such person  as it appears  on the  books of  the
Company,  and shall bear interest from the fifteenth day of January, April, July
or October, as the case may be, to which interest has been paid on the bonds  of
the  Designated Series (unless the date of such  bond is prior to July 15, 1994,
in which case  it shall bear  interest from March  21, 1994), 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  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. Bonds of the Designated Series shall bear interest at the three
month London interbank  offered rate ("LIBOR")  plus .15 per  cent per annum  as
calculated  and  reset in  the manner  and at  the times  as described  below in
Section 3, payable quarterly on the  fifteenth days of January, April, July  and
October  in each year (the "Interest Payment Dates"). The first interest payment
shall be made on  July 15, 1994.  The interest payable  on any interest  payment
date  shall be paid to the persons in whose names bonds of the Designated Series
were registered at the close of business on the record date for such payment  of
interest  notwithstanding any cancellation of bonds  of the Designated Series on
any transfer or  exchange thereof  between such  record date  and such  interest
payment  date; except that  if the Company  shall default in  the payment of any
interest due on such interest payment date such defaulted interest shall be paid
to the persons  in whose  names bonds of  the Designated  Series are  registered
either at the close of business on the subsequent

                                       73

record  date  fixed for  payment  of such  defaulted  interest, or  (if  no such
subsequent record date shall have  been fixed) at the  close of business on  the
day  preceding  the date  of payment  of such  defaulted interest.  A subsequent
record date for payment of defaulted interest may be established by or on behalf
of the Company by notice to holders  of bonds of the Designated Series 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 herein  shall mean, with respect  to any regular interest  payment
date, the close of business on the last day of the calendar month next preceding
such  interest payment date.  The bonds may  also be represented  by a permanent
global bond or bonds, registered in the name of The Depository Trust Company, as
depositary (the "Depositary"), or  a nominee of the  Depositary (each such  bond
represented by a permanent global bond being referred to herein as a "Book-Entry
Bond").  Beneficial interests in Book-Entry Bonds will only be evidenced by, and
transfers thereof  will only  be  effected through,  records maintained  by  the
Depositary's  participants. The Company shall not  be required to make transfers
or exchanges of bonds of the Designated  Series during a period of fifteen  days
preceding the mailing of notice of a partial redemption of bonds of such Series,
or  to  transfer or  exchange bonds  of  the Designated  Series, or  the portion
thereof, which  shall have  been designated  for redemption.  Upon thirty  days'
notice  in  the  manner set  forth  in Article  X,  Section 2  of  the Refunding
Mortgage, bonds  of the  Designated  Series at  any  time outstanding  shall  be
redeemable  prior to maturity, as a  whole at any time, or  in part from time to
time, at the option  of the Company,  at 100% of  principal amount, if  redeemed
otherwise than by operation of the sinking fund, and, at any time after July 31,
1996,  by operation of the sinking fund provided  for by Article X, Section 3 of
the Refunding Mortgage, at  100% of principal amount,  with accrued interest  to
the date of redemption, provided, however, that prior to April 15, 1996, none of
the bonds of the Designated Series may be redeemed.

    3.   Bonds of the Designated Series  will bear interest at the interest rate
calculated based upon three month LIBOR  plus .15%. LIBOR will be determined  on
the second London Business Day (as defined below) prior to the first day of each
Interest Period (the "Interest Determination Date"). The period commencing on an
Interest  Payment Date and ending on  and excluding the next succeeding Interest
Payment Date is called an "Interest  Period," with the exception that the  first
Interest  Period shall extend  from March 21,  1994 to July  15, 1994, the first
Interest Payment Date. LIBOR will be determined by Bankers Trust Company  acting
as  calculation agent (the "Calculation Agent") in accordance with the following
provisions:

        (a) With  respect to  any  Interest Determination  Date, LIBOR  will  be
    determined  on the basis of the offered  rates for deposits of not less than
    $1,000,000 having  the index  maturity of  three months,  commencing on  the
    second  business  day on  which  dealings in  deposits  in U.S.  dollars are
    transacted  in  the   London  interbank  market   ("London  Business   Day")
    immediately  following such Interest Determination Date, which appear on the
    Reuters Screen LIBO  Page as of  11:00 A.M., London  time, on that  Interest
    Determination Date. If at least two such offered rates appear on the Reuters
    Screen  LIBO Page, the rate for such Interest Determination Date will be the
    arithmetic mean  of such  offered  rates as  determined by  the  Calculation
    Agent.

        (b)  With respect to an Interest  Determination Date on which fewer than
    two offered rates for the three  month index maturity appear on the  Reuters
    Screen  LIBO Page as described in (a) above, LIBOR will be determined on the
    basis of  the  rates at  approximately  11:00  A.M., London  time,  on  such
    Interest  Determination Date  at which deposits  in U.S.  dollars having the
    three month  index  maturity  are  offered to  prime  banks  in  the  London
    interbank market by four major banks in the London interbank market selected
    by  the  Calculation  Agent commencing  on  the second  London  Business Day
    immediately following such  Interest Determination Date  and in a  principal
    amount  not less than $1,000,000 that in the Calculation Agent's judgment is
    representative for  a single  transaction in  such market  at such  time  (a
    "Representative  Amount"). The Calculation Agent  will request the principal
    London office of each of such banks  to provide a quotation of its rate.  If
    at  least  two  such  quotations  are  provided,  LIBOR  for  such  Interest
    Determination Date will be the arithmetic mean of such quotations. If  fewer
    than two quotations are provided, LIBOR for such Interest Determination Date
    will be the arithmetic mean of the rates quoted at approximately 11:00 A.M.,
    New York City time, on such Interest Determination Date by three major banks
    in  The City of  New York, selected  by the Calculation  Agent, for loans in
    U.S. dollars to leading European banks having the three month index maturity
    commencing on  the second  London Business  Day immediately  following  such
    Interest  Determination  Date  and  in  a  Representative  Amount; PROVIDED,
    HOWEVER, that  if  fewer than  three  banks  selected as  aforesaid  by  the
    Calculation  Agent are  quoting as mentioned  in this sentence,  the rate of
    interest in effect for the applicable period will be the same as the rate of
    interest in effect for the immediately preceding Interest Period.

    4.  The  recitals of  fact contained herein,  in the  Refunding Mortgage  as
hereby   supplemented,  and  in  the  bonds   (other  than  the  certificate  of
authentication of the Trustee on the bonds), shall be taken as the statements of
the Company, and the  Trustee assumes no responsibility  for the correctness  of
the  same. The Trustee  makes no representations  to the value  of the mortgaged
property or any part thereof, or as to  the title of the Company thereto, or  as
to  the value or validity of the  security afforded thereby and by the Refunding
Mortgage, or as to the

                                       74

value or  validity  of any  securities  at any  time  held under  the  Refunding
Mortgage,  or as to the validity of this supplemental indenture or the Refunding
Mortgage or  of the  bonds issued  thereunder, and  the Trustee  shall incur  no
responsibility,  except  as otherwise  provided  in the  Refunding  Mortgage, in
respect of such matters.

    5.  If and to the extent  that any provision of this supplemental  indenture
limits, qualifies, or conflicts with another provision of the Refunding Mortgage
required to be included therein by any of Sections 310 to 317, inclusive, of the
Trust  Indenture Act of 1939, as amended, such required provision shall control;
provided, however that nothing in this supplemental indenture contained shall be
so construed as to relieve the Company or the Trustee of any duty or  obligation
which  it would  otherwise have to  any holder  of any bond  or bonds heretofore
issued under the Refunding Mortgage, or so construed as to grant to the  Trustee
any  rights as against any  holder of bond or  bonds heretofore issued under the
Refunding Mortgage not granted under  said Refunding Mortgage, and no  provision
in  this supplemental indenture contained shall impair  any of the rights of any
holder of any bond or bonds heretofore issued under the Refunding Mortgage.

    6.  All the provisions of this supplemental indenture shall become effective
immediately. This supplemental  indenture and all  the provisions thereof  shall
form  a part  of the  Refunding Mortgage  and all  references or  mention in the
Refunding Mortgage to the Refunding Mortgage or to any of the terms, provisions,
covenants, conditions,  uses or  trusts thereof  or the  recitals or  statements
therein  or to the recording, filing or refiling thereof, shall be applicable to
the terms,  provisions,  covenants, conditions,  uses  and trusts  of,  and  the
recitals  and  statements  in,  this supplemental  indenture  and  the Refunding
Mortgage as  hereby supplemented,  and  to the  recording, filing  and  refiling
thereof,  as fully  and with  the same  force and  effect as  if all  the terms,
provisions, covenants, conditions, uses and trusts of, and all the recitals  and
statements  in, the Refunding Mortgage were herein again set forth at length and
the entire Refunding Mortgage  as hereby supplemented were  herein set forth  at
length as one new instrument.

    IN  TESTIMONY WHEREOF, on this fourteenth  day of March, 1994, Baltimore Gas
and Electric Company  has caused these  presents to be  signed in its  corporate
name by its President or a Vice President, and its corporate seal to be hereunto
affixed,  duly attested by its Secretary  or an Assistant Secretary; and Bankers
Trust Company has also caused these presents to be signed in its corporate  name
by  its President or  a Vice President  or an Assistant  Vice President, and its
corporate seal to  be hereunto affixed,  duly attested by  one of its  Assistant
Secretaries.

                                           BALTIMORE GAS AND ELECTRIC COMPANY,
                                          By __________/s/_C.W. SHIVERY_________
                                                       Vice President

Attest _______/s/_L.H. CHURCH______ (Seal)
           Assistant Secretary


                         
STATE OF MARYLAND:          SS:
CITY OF BALTIMORE:


    I HEREBY CERTIFY, that on this fourteenth day of March, 1994, before me, the
subscriber,  a Notary Public  of the State of  Maryland, in and  for the City of
Baltimore  aforesaid,  personally  appeared  C.W.  Shivery,  Vice  President  of
Baltimore  Gas and Electric Company,  and on behalf of  the said corporation did
acknowledge the foregoing instrument to be the act and deed of Baltimore Gas and
Electric Company.

    IN TESTIMONY WHEREOF, I have hereunto set  my hand and Notarial Seal on  the
day and year aforesaid.

                                          ___________/s/_GWEN SMETANA___________
                                                      Notary Public

                                              My Commission expires 11/17/97

                 [BANKERS TRUST COMPANY signature on next page]

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                                                  BANKERS TRUST COMPANY,
                                          By ________/s/_ROBERT CAPORALE________
                                                       Vice President

Attest ______/s/_SHIKHA DOMBEK_____ (Seal)
           Assistant Secretary


                         
STATE OF NEW YORK:          SS:
COUNTY OF NEW YORK:


    I  HEREBY CERTIFY,  that on  this 14th  day of  March, 1994,  before me, the
subscriber, a Notary Public of the State of  New York, in and for the County  of
New  York  aforesaid, personally  appeared  Robert Caporale,  Vice  President of
Bankers Trust Company, and on behalf of the said corporation did acknowledge the
foregoing instrument to be the act and deed of Bankers Trust Company; and at the
same time such Vice President, for and on behalf of said corporation, made  oath
in  due form of law that the consideration stated in the foregoing deed of trust
is true and  bona fide  as therein set  forth, and  also that he/she  is a  Vice
President  and agent of the said Bankers  Trust Company, Trustee, grantee in the
foregoing instrument and duly authorized to make this affidavit.

    IN TESTIMONY WHEREOF, I have hereunto set  my hand and Notarial Seal on  the
day and year aforesaid.

                                          ____________/s/_JOHN FLORIO___________
                                                      Notary Public

                                              My Commission expires 12/20/95

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                            CERTIFICATE OF RESIDENCE

    Bankers  Trust Company, Mortgagee and Trustee within named, hereby certifies
that its precise residence is Four  Albany Street, in the Borough of  Manhattan,
in The City of New York, in the State of New York.

                                          BANKERS TRUST COMPANY,

                                          By ________/s/_ROBERT CAPORALE________
                                                       Vice President

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