EXHIBIT 4(a)


FIRST SUPPLEMENTAL INDENTURE, dated as of October 13,
2006 (this “First Supplemental Indenture”), between BALTIMORE GAS AND
ELECTRIC COMPANY, a Maryland corporation (the “Issuer”) and DEUTSCHE BANK
TRUST COMPANY AMERICAS,
as trustee (the “Trustee”).


W I T N E S S E T
H


WHEREAS, the Issuer and the Trustee have duly executed
and delivered an Indenture, dated as of July 24, 2006 (the “Indenture”),
providing for the authentication, issuance, delivery and administration of
unsecured debentures, notes or other evidences of indebtedness to be issued in
one or more series by the Issuer (the “Securities”);


WHEREAS, pursuant to the terms of the Indenture, the
Issuer desires to provide for the establishment of new series of Securities
(the “Notes”) to be issued under the Indenture in an unlimited aggregate
principal amount, which may be authenticated and delivered as provided in the
Indenture;


WHEREAS, the Issuer desires to amend the provisions of
the Indenture to issue the Notes under the terms of the Indenture as
supplemented hereby;


WHEREAS, Section 11.01 of the Indenture expressly
permits the Issuer and the Trustee to enter into one or more supplemental
indentures for the purposes, inter alia, of establishing the forms and terms of
Securities to be issued under the Indenture or making certain provisions in the
Indenture which the Issuer deems necessary or desirable, and permits the
execution of such supplemental indentures without the consent of the Holders of
any Securities then outstanding;


WHEREAS, for the purposes hereinabove recited, and
pursuant to due corporate action, the Issuer has duly determined to execute and
deliver to the Trustee this First Supplemental Indenture; and


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


NOW, THEREFORE, in consideration of the premises, the
Issuer and the Trustee mutually covenant and agree as follows:


SECTION 1.           DEFINITIONS.


1.1           All
terms contained in this First Supplemental Indenture shall, except as
specifically provided herein or except as the context may otherwise require,
have the meanings given to such terms in the Indenture.









 



1.2           Unless
the context otherwise requires, the following terms shall have the following
meanings:


“Affiliate” of any specified person means any
other person directly or indirectly controlling or controlled by or under
direct or indirect common control with such specified person. For the purposes
of this definition, “control” when used with respect to any specified person
means the power to direct or cause the direction of the management and policies
of such person, directly or indirectly, whether through the ownership of voting
securities, by contract or otherwise; and the terms “controlling” and “controlled”
have meanings correlative to the foregoing.


“Applicable Procedures” means, with respect to
any transfer or exchange of or for beneficial interests in any Global Note, the
rules and procedures of the Depositary that apply to such transfer or exchange.


“Depositary” means The Depository Trust Company
or any other depositary from time to time specified pursuant to the Indenture.


“Definitive Note” means a certificated Note
registered in the name of the Holder thereof and issued in accordance with
Section 4 hereof, substantially in the form of Exhibit A or B hereto except
that such Note shall not bear the Global Note Legend and shall not have the “Schedule
of Exchanges of Interests in the Global Note” attached thereto.


“Exchange Notes” has the meaning set forth in
the Registration Rights Agreement.


“Exchange Offer” has the meaning set forth in
the Registration Rights Agreement.


“Exchange Offer Registration Statement” has the
meaning set forth in the Registration Rights Agreement.


“Global Note Legend” means the legend set forth
in Section 4.7(b) which is required to be placed on all Global Notes issued
under this First Supplemental Indenture.


“Global Notes” means, individually and
collectively, each of the Restricted Global Notes and the Unrestricted Global
Notes, substantially in the form of Exhibit A or B hereto that bears the Global
Note Legend and that has the “Schedule of Exchanges of Interests in the Global
Note” attached thereto, issued in accordance with Section 4.2(d), 4.4(b) or 4.6
hereof.


“Indirect Participant” means a person who holds
a beneficial interest in a Global Note through a Participant.


“Initial Purchasers” has the meaning set forth
in the Purchase Agreement dated as of October 11, 2006, by and among the
Issuer, Banc of America Securities LLC, Barclays Capital Inc., Citigroup Global
Markets Inc. and Merrill Lynch, Pierce, Fenner & Smith Incorporated (as representatives
of the several Initial Purchasers).



 2
 






 



“Letter of Transmittal” means the letter of
transmittal to be prepared by the Issuer and sent to all Holders of the Notes
for use by such Holders in connection with the Exchange Offer.


“Non-U.S. Person” means any person that is not
a U.S. person as defined in Rule 902(o) under the Securities Act.


“Notes” means the 5.90% Notes due 2016 and the 6.35%
Notes due 2036 as those notes are defined in Sections 2.1 and 2.2,
respectively.


“Participant” means a person who has an account
with the Depositary.


“Participating Broker-Dealer” has the meaning
set forth in the Registration Rights Agreement.


“Private Exchange” has the meaning set forth in
the Registration Rights Agreement.


“Private Exchange Notes” has the meaning set
forth in the Registration Rights Agreement.


“Private Placement Legend” means the legend set
forth in Section 4.7(a) to be placed on all Notes issued under this First
Supplemental Indenture except where otherwise permitted by the provisions of
this First Supplemental Indenture.


“QIB” means a “qualified institutional buyer”
as defined in Rule l44A.


“Registrar” means the registrar specified from
time to time pursuant to Section 3.04 of the Indenture.


“Registration Rights Agreement” means each of the
Registration Rights Agreements for the 5.90% Notes and the 6.35% Notes,
respectively, dated as of the date hereof, by and among the Issuer, Banc of
America Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc.
and Merrill Lynch, Pierce, Fenner & Smith Incorporated (as representatives
of the several initial purchasers listed therein), as such agreements may be
amended, modified or supplemented from time to time.


“Regulation S” means Regulation S under the
Securities Act.


“Restricted Definitive Note” means a Definitive
Note bearing the Private Placement Legend.


“Restricted Global Note” means a Global Note
bearing the Private Placement Legend.


“Ru1e 144” means Rule 144 promulgated under the
Securities Act.


“Rule 144A” means Rule 144A promulgated under
the Securities Act.



 3
 






 



“Securities Act” means the Securities Act of
1933, as amended.


“Shelf Registration Statement” has the meaning
set forth in the Registration Rights Agreement.


“Unrestricted Definitive Note” means one or
more Definitive Notes that do not bear and, pursuant to Section 4.7, are not
required to bear the Private Placement Legend.


“Unrestricted Global Note” means one or more
Global Notes that do not bear and, pursuant to Section 4.7, are not required to
bear the Private Placement Legend.


SECTION 2.           TERMS AND CONDITIONS OF THE SECURITIES.


There is hereby authorized the following series of
Notes:


2.1           5.90%
Notes due 2016.


(a)           A
single series consisting of two tranches of senior unsecured notes
(collectively, the “5.90% Notes due 2016”) are hereby authorized and designated
as the “5.90% Series A Notes due 2016” and the “5.90% Series B Notes due 2016”.


(b)           The
5.90% Notes due 2016 shall initially be limited in aggregate principal amount
to $300,000,000, shall bear interest at a rate of 5.90% per annum (plus
additional interest, if any, pursuant to the applicable Registration Rights
Agreement), shall mature on October 1, 2016, shall be subject to optional
redemption at any time by the Issuer pursuant to the terms set forth in the
form of Note with respect thereto attached as Exhibit A and have such other
terms set forth in such form of Note.


(c)           The
5.90% Series A Notes due 2016 and the 5.90% Series B Notes due 2016 shall be
identical in all material respects except that the (i) 5.90% Series A Notes due
2016 and any 5.90% Series A Notes due 2016 issued in the Private Exchange shall
be issued bearing the Private Placement Legend and (ii) 5.90% Series B Notes due
2016 issued pursuant to the Exchange Offer shall be issued without bearing the
Private Placement Legend.  It is intended
that the 5.90% Series A Notes due 2016 will be exchanged for the 5.90% Series B
Notes due 2016 pursuant to Section 4.6 hereof.


2.2           6.35%
Notes due 2036.


(a)           A
single series consisting of two tranches of senior unsecured notes (collectively,
the “6.35% Notes due 2036”) are hereby authorized and designated as the “6.35%
Series A Notes due 2036” and the “6.35% Series B Notes due 2036”.


(b)           The
6.35% Notes due 2036 shall initially be limited in aggregate principal amount
to $400,000,000, shall bear interest at a rate of 6.35% per annum (plus
additional interest, if any, pursuant to the applicable Registration Rights
Agreement), shall mature on October 1, 2036, shall be subject to optional
redemption at any time by the Issuer pursuant to the terms set forth in the form
of Note with respect thereto attached as Exhibit B and have such other terms
set forth in such form of Note.



 4
 






 



(c)           The
6.35% Series A Notes due 2036 and the 6.35% Series B Notes due 2036 shall be
identical in all material respects except that the (i) 6.35% Series B Notes due
2036 and any 6.35% Series B Notes due 2036 issued in the Private Exchange shall
be issued bearing the Private Placement Legend and (ii) 6.35% Series B Notes due
2036 issued pursuant to the Exchange Offer shall be issued without bearing the
Private Placement Legend.  It is intended
that the 6.35% Series A Notes due 2036 will be exchanged for the 6.35% Series B
Notes due 2036 pursuant to Section 4.6 hereof.


2.3           Issuance
of Additional Securities.  The Issuer shall be permitted
to amend this First Supplemental Indenture in order to increase the aggregate
principal amount of Notes that may be issued hereunder without the consent of
the Holders of Notes so affected.


SECTION 3.           FORM OF NOTES.


3.1           Form
of Global Notes.  The Notes shall be issued in the form of
Global Notes (including the Global Note Legend thereon and the “Schedule of
Exchanges of Interests in the Global Note” attached thereto).  Each Global Note shall represent such of the
outstanding Notes as shall be specified therein and each shall provide that it
shall represent the aggregate principal amount of outstanding Notes from time
to time endorsed thereon and that the aggregate principal amount of outstanding
Notes represented thereby may from time to time be reduced or increased, as
appropriate, to reflect exchanges and redemptions.  Any endorsement of a Global Note to reflect
the amount of any increase or decrease in the aggregate principal amount of
outstanding Notes represented thereby shall be made by the Trustee, as
custodian of the Global Notes, in accordance with instructions given by the
Holder thereof as required by Section 4 hereof.


SECTION 4.           TRANSFER AND EXCHANGE.


Notwithstanding any provisions to the contrary set
forth in Article Two of the Indenture, the following terms and conditions shall
govern the transfer and exchange of the Notes.


4.1           Transfer
and Exchange of Global Notes.  A Global Note
may not be transferred as a whole except by the Depositary to a nominee of the
Depositary, by a nominee of the Depositary to the Depositary or to another
nominee of the Depositary, the Depositary or any such nominee to a successor
Depositary or a nominee of such successor Depositary.  All Global Notes will be exchanged by the
Issuer for Definitive Notes if (i) the Issuer delivers to the Trustee notice
from the Depositary that it is unwilling or unable to continue to act as
Depositary or that it is no longer a clearing agency registered under the
Exchange Act and, in either case, a successor Depositary is not appointed by
the Issuer within 90 days after the date of such notice from the Depositary,
(ii) the Issuer in its sole discretion determines that the Global Notes (in
whole but not in part) should be exchanged for individual Notes and delivers a
written notice to such effect to the Trustee or (iii) an Event of Default shall
have occurred and be continuing with respect to the Notes.  Upon the occurrence of any of the preceding
events in (i), (ii) or (iii) above, Definitive Notes shall be issued in such
names as the Depositary shall instruct the Trustee.  Every Note 



 5
 






 



authenticated and
delivered in exchange for, or in lieu of, a Global Note or any portion thereof,
pursuant to this Section 4 hereof, shall be authenticated and delivered in the
form of, and shall be, a Global Note.  A
Global Note may not be exchanged for another Note other than as provided in
this Section 4, however, beneficial interests in
a Global Note may be transferred and exchanged as provided in Section 4.2, 4.3
or 4.6 hereof.


4.2           Transfer
and Exchange of Beneficial Interests in the Global Notes. 
The transfer and exchange of beneficial interests in the Global Notes
shall be effected through the Depositary, in accordance with the provisions of
the Indenture, as supplemented by this First Supplemental Indenture, and the
Applicable Procedures.  Beneficial
interests in any Restricted Global Note bearing the Private Placement Legend
shall be subject to restrictions on transfer comparable to those set forth
herein to the extent required by the Securities Act.  Transfers of beneficial interests in the
Global Notes also shall require compliance with either subparagraph (a) or (b)
below, as applicable, as well as one or more of the other following subparagraphs,
as applicable:


(a)           Transfer of Beneficial Interests in the Same Global Note. 
Beneficial interests in any Restricted Global Note may be transferred to
persons who take delivery thereof in the form of a beneficial interest in the
same Restricted Global Note in accordance with the transfer restrictions set
forth in the Private Placement Legend. 
Beneficial interests in any Unrestricted Global Note may be transferred
to persons who take delivery thereof in the form of a beneficial interest in an
Unrestricted Global Note.  No written
orders or instructions shall be required to be delivered to the Registrar to
register the transfers described in this Section 4.2(a).


(b)           All Other Transfers and Exchanges of Beneficial Interests in Global
Notes.  In connection with all transfers and
exchanges of beneficial interests that are not subject to Section 4.2(a) above,
the transferor of such beneficial interest must deliver to the Depositary
either (1) (A) a written order from a Participant or an Indirect Participant
given to the Depositary in accordance with the Applicable Procedures directing
the Depositary to credit or cause to be credited a beneficial interest in the
Global Note, or in another Global Note in the case of an exchange, in an amount
equal to the beneficial interest to be transferred or exchanged and (B)
instructions given in accordance with the Applicable Procedures containing
information regarding the Participant account to be credited with such increase
or (2) (A) a written order from a Participant or an Indirect Participant given
to the Depositary in accordance with the Applicable Procedures directing the
Depositary to cause to be issued a Definitive Note in an amount equal to the
beneficial interest to be transferred or exchanged and (B) instructions given
by the Depositary to the Registrar containing information regarding the person
in whose name such Definitive Note shall be registered to effect the transfer
or exchange referred to in (A) above. 
Upon consummation of an Exchange Offer by the Issuer in accordance with
Section 4.6 hereof, the requirements of this Section 4.2(b) shall be deemed to
have been satisfied upon receipt by the Registrar of the instructions contained
in the Letter of Transmittal delivered by the holder of such beneficial
interests in the Restricted Global Notes. 
Upon satisfaction of all of the requirements for transfer or exchange of
beneficial interests in Global Notes contained in the Indenture, as
supplemented by this First Supplemental Indenture, and the Notes or 



 6
 






 



otherwise
applicable under the Securities Act, the Trustee shall adjust the principal
amount of the relevant Global Note(s) pursuant to Section 4.8 hereof.


(c)           Transfer of Beneficial Interests to Another Restricted Global Note. 
A beneficial interest in any Restricted Global Note may be transferred
to a person who takes delivery thereof in the form of a beneficial interest in
another Restricted Global Note if the transfer complies with the requirements
of Section 4.2(b) above and the transferor delivers a certificate in the form
of Exhibit C hereto, including the certifications in item (1) thereof.


(d)           Transfer and Exchange of Beneficial Interests in a Restricted Global
Note for Beneficial Interests in the Unrestricted Global Note. 
A beneficial interest in any Restricted Global Note may be exchanged by any
holder thereof for a beneficial interest in an Unrestricted Global Note or
transferred to a person who takes delivery thereof in the form of a beneficial
interest in an Unrestricted Global Note if the exchange or transfer complies
with the requirements of Section 4.2(b) above and:


(i)            such exchange or transfer is effected pursuant to the
Exchange Offer in accordance with the Registration Rights Agreement and the
holder of the beneficial interest to be transferred, in the case of an
exchange, or the transferee, in the case of a transfer, certifies in the
applicable Letter of Transmittal or via the Depositary’s book-entry system that
it is not (A) a broker-dealer, (B) a person participating in the distribution
of the Exchange Notes or (C) a person who is an affiliate (as defined in Rule
144) of the Issuer; or


(ii)           such transfer is effected pursuant to the Shelf
Registration Statement in accordance with the Registration Rights Agreement; or


(iii)          such transfer is effected by a Participating
Broker-Dealer pursuant to the Exchange Offer Registration Statement in
accordance with the Registration Rights Agreement; or


(iv)          the Registrar receives the following:


(A)          if the holder of such
beneficial interest in a Restricted Global Note proposes to exchange such beneficial
interest for a beneficial interest in an Unrestricted Global Note, a
certificate from such holder in the form of Exhibit D hereto, including the
certifications in item (1 )(a) thereof; or


(B)           if the holder of such
beneficial interest in a Restricted Global Note proposes to transfer such
beneficial interest to a person who shall take delivery thereof in the form of
a beneficial interest in an Unrestricted Global Note, a certificate from such
holder in the form of Exhibit C hereto, including the certifications in item
(4) thereof;



 7
 






 



and, in each such case
set forth in this subparagraph (iv), if the Registrar so requests or if the
Applicable Procedures so require, an Opinion of Counsel in form reasonably
acceptable to the Registrar to the effect that such exchange or transfer is in
compliance with the Securities Act and that the restrictions on transfer
contained herein and in the Private Placement Legend are no longer required in
order to maintain compliance with the Securities Act.


If any such transfer is effected pursuant to
subparagraph (ii) or (iv) above at a time when an Unrestricted Global Note has
not yet been issued, the Issuer shall issue and, upon receipt of an Issuer
Order in accordance with Section 2.4 of the Indenture, the Trustee shall authenticate
one or more Unrestricted Global Notes in an aggregate principal amount equal to
the aggregate principal amount of beneficial interests transferred pursuant to
subparagraph (ii) or (iv) above.


Beneficial interests in an Unrestricted Global Note
cannot be exchanged for, or transferred to persons who take delivery thereof in
the form of, a beneficial interest in a Restricted Global Note.


4.3           Transfer
or Exchange of Beneficial Interests for Definitive Notes.


(a)           Beneficial Interests in Restricted Global Notes to Restricted
Definitive Notes.  If any holder of a beneficial interest in a
Restricted Global Note proposes to exchange such beneficial interest for a
Restricted Definitive Note or to transfer such beneficial interest to a person
who takes delivery thereof in the form of a Restricted Definitive Note, then,
upon receipt by the Registrar of the following documentation:


(i)            if the holder of such beneficial interest in a
Restricted Global Note proposes to exchange such beneficial interest for a
Restricted Definitive Note, a certificate from such holder in the form of
Exhibit D hereto, including the certifications in item (2)(a) thereof;


(ii)           if such beneficial interest is being transferred to a
QIB in accordance with Rule l44A, a certificate to the effect set forth in
Exhibit C hereto, including the certifications in item (1) thereof;


(iii)          if such beneficial interest is being transferred to a
Non-U.S. Person in an offshore transaction in accordance with Rule 903 or Rule
904 under the Securities Act, a certificate to the effect set forth in Exhibit C
hereto, including the certifications in item (2) thereof;


(iv)          if such beneficial interest is being transferred
pursuant to an exemption from the registration requirements of the Securities
Act in accordance with Rule 144, a certificate to the effect set forth in
Exhibit C hereto, including the certifications in item (3)(a) thereof;



 8
 






 



(v)           if such beneficial interest is being transferred to
the Issuer or any of its Subsidiaries, a certificate to the effect set forth in
Exhibit C hereto, including the certifications in item (3)(b) thereof; or


(vi)          if such beneficial interest is being transferred
pursuant to an effective registration statement under the Securities Act, a
certificate to the effect set forth in Exhibit C hereto, including the
certifications in item (3)(c) thereof,


the Trustee shall cause
the aggregate principal amount of the applicable Global Note to be reduced
accordingly pursuant to Section 4.8 hereof, and the Issuer shall execute and
the Trustee shall authenticate and deliver to the person designated in the
instructions a Definitive Note in the appropriate principal amount.  Any Definitive Note issued in exchange for a
beneficial interest in a Restricted Global Note pursuant to this Section 4.3(a)
shall be registered in such name or names and in such authorized denomination
or denominations as the holder of such beneficial interest shall instruct the
Registrar through instructions from the Depositary and the Participant or
Indirect Participant.  The Trustee shall
make available for delivery such Definitive Notes to the persons in whose names
such Notes are so registered.  Any
Definitive Note issued in exchange for a beneficial interest in a Restricted
Global Note pursuant to this Section 4.3(a) shall bear the Private Placement
Legend and shall be subject to all restrictions on transfer contained therein.


(b)           Beneficial Interests in Restricted Global Notes to Unrestricted
Definitive Notes.  A holder of a beneficial interest in a
Restricted Global Note may exchange such beneficial interest for an
Unrestricted Definitive Note or may transfer such beneficial interest to a
person who takes delivery thereof in the form of an Unrestricted Definitive
Note only if:


(i)            such exchange or transfer is effected pursuant to the
Exchange Offer in accordance with the Registration Rights Agreement and the
holder of such beneficial interest, in the case of an exchange, or the
transferee, in the case of a transfer, certifies in the applicable Letter of
Transmittal that it is not (1) a broker-dealer, (2) a person participating in
the distribution of the Exchange Notes or (3) a person who is an affiliate (as
defined in Rule 144) of the Issuer;


(ii)           such transfer is effected pursuant to the Shelf
Registration Statement in accordance with the Registration Rights Agreement;


(iii)          such transfer is effected by a Participating
Broker-Dealer pursuant to the Exchange Offer Registration Statement in
accordance with the Registration Rights Agreement; or


(iv)          the Registrar receives the following:


(A)          if the holder of such beneficial interest in a
Restricted Global Note proposes to exchange such beneficial interest for a
Definitive Note that does not bear the Private Placement Legend, a certificate
from such holder in the 



 9
 






 



form of Exhibit D
hereto, including the certifications in item (l)(b) thereof; or


(B)           if the holder of such beneficial interest in a
Restricted Global Note proposes to transfer such beneficial interest to a
person who shall take delivery thereof in the form of a Definitive Note that
does not bear the Private Placement Legend, a certificate from such holder in
the form of Exhibit C hereto, including the certifications in item (4) thereof;


and, in each such case
set forth in this subparagraph (iv), if the Registrar so requests or if the
Applicable Procedures so require, an Opinion of Counsel in form reasonably
acceptable to the Registrar to the effect that such exchange or transfer is in
compliance with the Securities Act and that the restrictions on transfer
contained herein and in the Private Placement Legend are no longer required in
order to maintain compliance with the Securities Act.


(c)           Beneficial Interests in Unrestricted Global Notes to Unrestricted
Definitive Notes.  If any holder of a beneficial interest in an
Unrestricted Global Note proposes to exchange such beneficial interest for a
Definitive Note or to transfer such beneficial interest to a person who takes
delivery thereof in the form of a Definitive Note, then, upon satisfaction of
the conditions set forth in Section 4.2(b) hereof, the Trustee shall cause the
aggregate principal amount of the applicable Global Note to be reduced
accordingly pursuant to Section 4.8 hereof, and the Issuer shall execute and
the Trustee shall authenticate and make available for delivery to the person
designated in the instructions a Definitive Note in the appropriate principal
amount.  Any Definitive Note issued in
exchange for a beneficial interest pursuant to this Section 4.3(c) shall be
registered in such name or names and in such authorized denomination or
denominations as the holder of such beneficial interest shall instruct the
Registrar through instructions from the Depositary and the Participant or
Indirect Participant.  The Trustee shall make
available for delivery such Definitive Notes to the persons in whose names such
Notes are so registered.  Any Definitive
Note issued in exchange for a beneficial interest pursuant to this Section
4.3(c) shall not bear the Private Placement Legend.


4.4           Transfer
and Exchange of Definitive Notes for Beneficial Interests.


(a)           Restricted Definitive Notes to Beneficial Interests in Restricted
Global Notes.  If any Holder of a Restricted Definitive Note
proposes to exchange such Note for a beneficial interest in a Restricted Global
Note or to transfer such Restricted Definitive Notes to a person who takes
delivery thereof in the form of a beneficial interest in a Restricted Global
Note, then, upon receipt by the Registrar of the following documentation:


(i)            if the Holder of such Restricted Definitive Note
proposes to exchange such Note for a beneficial interest in a Restricted Global
Note, a certificate from such Holder in the form of Exhibit D hereto, including
the certifications in item (2)(b) thereof;



 10
 






 



(ii)           if such Restricted Definitive Note is being
transferred to a QIB in accordance with Rule l44A, a certificate to the effect
set forth in Exhibit C hereto, including the certifications in item (1)
thereof;


(iii)          if such Restricted Definitive Note is being
transferred to a Non-U.S. Person in an offshore transaction in accordance with
Rule 903 or Rule 904 under the Securities Act, a certificate to the effect set
forth in Exhibit C hereto, including the certifications in item (2) thereof;


(iv)          if such Restricted Definitive Note is being
transferred pursuant to an exemption from the registration requirements of the
Securities Act in accordance with Rule 144, a certificate to the effect set
forth in Exhibit C hereto, including the certifications in item (3)(a) thereof;


(v)           if such Restricted Definitive Note is being
transferred to the Issuer or any of its Subsidiaries, a certificate to the
effect set forth in Exhibit C hereto, including the certifications in item
(3)(b) thereof; or


(vi)          if such Restricted Definitive Note is being
transferred pursuant to an effective registration statement under the
Securities Act, a certificate to the effect set forth in Exhibit C hereto,
including the certifications in item (3)(c) thereof;


the Trustee shall cancel
the Restricted Definitive Note, increase or cause to be increased the aggregate
principal amount of the appropriate Restricted Global Note.


(b)           Restricted Definitive Notes to Beneficial Interests in Unrestricted
Global Notes.  A Holder of a Restricted Definitive Note may
exchange such Note for a beneficial interest in an Unrestricted Global Note or
transfer such Restricted Definitive Note to a person who takes delivery thereof
in the form of a beneficial interest in an Unrestricted Global Note only if:


(i)            such exchange or transfer is effected pursuant to the
Exchange Offer in accordance with the Registration Rights Agreement and the
Holder, in the case of an exchange, or the transferee, in the case of a
transfer, certifies in the applicable Letter of Transmittal that it is not (1)
a broker-dealer, (2) a person participating in the distribution of the Exchange
Notes or (3) a person who is an affiliate (as defined in Rule 144) of the
Issuer;


(ii)           such transfer is effected pursuant to the Shelf
Registration Statement in accordance with the Registration Rights Agreement;


(iii)          such transfer is effected by a Participating
Broker-Dealer pursuant to the Exchange Offer Registration Statement in
accordance with the Registration Rights Agreement; or


(iv)          the Registrar receives the following:



 11
 






 



(A)          if the Holder of such Definitive Notes proposes to
exchange such Notes for a beneficial interest in the Unrestricted Global Note,
a certificate from such Holder in the form of Exhibit D hereto, including the
certifications in item (1)(c) thereof; or


(B)           if the Holder of such Definitive Notes proposes to
transfer such Notes to a person who shall take delivery thereof in the form of
a beneficial interest in the Unrestricted Global Note, a certificate from such
Holder in the form of Exhibit C hereto, including the certifications in item (4)
thereof;


and, in each such case
set forth in this subparagraph (iv), if the Registrar so requests or if the
Applicable Procedures so require, an Opinion of Counsel in form reasonably
acceptable to the Registrar to the effect that such exchange or transfer is in
compliance with the Securities Act and that the restrictions on transfer
contained herein and in the Private Placement Legend are no longer required in
order to maintain compliance with the Securities Act.


Upon satisfaction of the conditions of any of the
subparagraphs in this Section 4.4(b), the Trustee shall cancel the Definitive
Notes and increase or cause to be increased the aggregate principal amount of
the Unrestricted Global Note.


(c)           Unrestricted Definitive Notes to Beneficial Interests in Unrestricted
Global Notes.  A Holder of an Unrestricted Definitive Note
may exchange such Note for a beneficial interest in an Unrestricted Global Note
or transfer such Definitive Notes to a person who takes delivery thereof in the
form of a beneficial interest in an Unrestricted Global Note at any time.  Upon receipt of a request for such an
exchange or registration of transfer, the Trustee shall cancel the applicable
Unrestricted Definitive Note and increase or cause to be increased the
aggregate principal amount of one of the Unrestricted Global Notes.


If any such exchange or registration of transfer from
a Definitive Note to a beneficial interest in a Global Note is effected
pursuant to subparagraphs (b)(ii), (b)(iv) or (c) above at a time when an
Unrestricted Global Note has not yet been issued, the Issuer shall issue and,
upon receipt of an Issuer Order in accordance with Section 2.4 of the
Indenture, the Trustee shall authenticate one or more Unrestricted Global Notes
in an aggregate principal amount equal to the principal amount of Definitive
Notes so transferred.


4.5           Transfer
and Exchange of Definitive Notes for Definitive Notes. 
Upon request by a Holder of Definitive Notes and such Holder’s
compliance with the provisions of this Section 4.5, the Registrar shall
register the transfer or exchange of Definitive Notes.  Prior to such registration of transfer or
exchange, the requesting Holder shall present or surrender to the Registrar the
Definitive Notes duly endorsed or accompanied by a written instruction of
transfer in form satisfactory to the Registrar duly executed by such Holder or
by his attorney, duly authorized in writing. 
In addition, the requesting Holder shall provide 



 12
 






 



any additional
certifications, documents and information, as applicable, required pursuant to
the following provisions of this Section 4.5.


(a)           Restricted Definitive Notes to Restricted Definitive Notes. 
Any Restricted Definitive Note may be transferred to and registered in
the name of persons who take delivery thereof in the form of a Restricted
Definitive Note if the Registrar receives the following:


(i)            if the transfer will be made pursuant to Rule l44A,
then the transferor must deliver a certificate in the form of Exhibit C hereto,
including the certifications in item (1) thereof; and


(ii)           if the transfer will be made pursuant to Rule 903 or
Rule 904 under the Securities Act, then the transferor must deliver a
certificate in the form of Exhibit C hereto, including the certifications in
item (2) thereof;


(iii)          if the transfer will be made pursuant to any other
exemption from the registration requirements of the Securities Act, then the
transferor must deliver a certificate in the form of Exhibit C hereto,
including the certifications, certificates and Opinion of Counsel required by
item (3) thereof, if applicable.


(b)           Restricted Definitive Notes to Unrestricted Definitive Notes. 
Any Restricted Definitive Note may be exchanged by the Holder thereof
for an Unrestricted Definitive Note or transferred to a person or persons who take
delivery thereof in the form of an Unrestricted Definitive Note if:


(i)            such exchange or transfer is effected pursuant to the
Exchange Offer in accordance with the Registration Rights Agreement and the
Holder, in the case of an exchange, or the transferee, in the case of a
transfer, certifies in the applicable Letter of Transmittal that it is not (1)
a broker-dealer, (2) a person participating in the distribution of the Exchange
Notes or (3) a person who is an affiliate (as defined in Rule 144) of the Issuer;


(ii)           any such transfer is effected pursuant to the Shelf
Registration Statement in accordance with the Registration Rights Agreement;


(iii)          any such transfer is effected by a Participating
Broker-Dealer pursuant to the Exchange Offer Registration Statement in
accordance with the Registration Rights Agreement; or


(iv)          the Registrar receives the following:


(A)          if the Holder of such Restricted Definitive Notes
proposes to exchange such Notes for an Unrestricted Definitive Note, a
certificate from such Holder in the form of Exhibit D hereto, including the
certifications in item (1)(d) thereof; or



 13
 






 



(B)           if the Holder of such Restricted Definitive Notes
proposes to transfer such Notes to a person who shall take delivery thereof in
the form of an Unrestricted Definitive Note, a certificate from such Holder in
the form of Exhibit C hereto, including the certifications in item (4) thereof;


and, in each such case
set forth in this subparagraph (iv), if the Registrar so requests, an Opinion
of Counsel in form reasonably acceptable to the Issuer to the effect that such
exchange or transfer is in compliance with the Securities Act and that the
restrictions on transfer contained herein and in the Private Placement Legend
are no longer required in order to maintain compliance with the Securities Act.


(c)           Unrestricted Definitive Notes to Unrestricted Definitive Notes. 
A Holder of Unrestricted Definitive Notes may transfer such Notes to a
person who takes delivery thereof in the form of an Unrestricted Definitive
Note.  Upon receipt of a request to
register such a transfer, the Registrar shall register the Unrestricted
Definitive Notes pursuant to the instructions from the Holder thereof.


4.6           Exchange
Offer.  Upon the occurrence of the Exchange Offer in
accordance with the Registration Rights Agreement, the Issuer shall issue and,
upon receipt of an Issuer Order in accordance with Section 2.4 of the
Indenture, the Trustee shall authenticate (i) one or more Unrestricted Global
Notes in an aggregate principal amount equal to the principal amount of the
beneficial interests in the Restricted Global Notes tendered for acceptance by
persons that certify in the applicable Letters of Transmittal or via the
Depositary’s book-entry system that (x) they are not broker-dealers, (y) they
are not participating in a distribution of the Exchange Notes and (z) they are
not affiliates (as defined in Rule 144) of the Issuer, and accepted for
exchange in the Exchange Offer and (ii) Definitive Notes in an aggregate
principal amount equal to the principal amount of the Restricted Definitive
Notes accepted for exchange in the Exchange Offer.  In addition, if pursuant to the Registration
Rights Agreement, any Holder is entitled to receive Private Exchange Notes
simultaneously with the consummation of the Exchange Offer and so requests, the
Issuer shall issue and, upon receipt of an Issuer Order in accordance with
Section 2.4 of the Indenture, the Trustee shall authenticate (i) one or more
Restricted Global Notes that are identical in all material respects to the
Exchange Notes, except for the Private Placement Legend, in an aggregate
principal amount equal to the principal amount of the beneficial interests in
the Restricted Global Notes accepted for exchange in the Private Exchange and
(ii) Restricted Definitive Notes that are identical in all material respects to
the Exchange Notes, except for the Private Placement Legend, in an aggregate
principal amount equal to the principal amount of the Restricted Definitive
Notes accepted for exchange in the Private Exchange.  Concurrently with the issuance of such Notes,
the Trustee shall cause the aggregate principal amount of the applicable
Restricted Global Notes to be reduced accordingly, and the Issuer shall execute
and the Trustee shall authenticate and make available for delivery to the
persons designated by the Holders of Definitive Notes so accepted Definitive
Notes in the appropriate principal amount.


4.7           Legends. 
The following legends shall appear on the face of all Global Notes and
Definitive Notes issued under this First Supplemental Indenture unless
specifically stated otherwise in the applicable provisions hereof:



 14
 






 



(a)           Private Placement Legend.  Except as
permitted by subparagraph (b) below, each Global Note and each Definitive Note
(and all Notes issued in exchange therefor or substitution thereof) shall bear
the legend in substantially the following form:


“THE HOLDER OF
THIS SECURITY BY ITS ACCEPTANCE HEREOF IS DEEMED TO HAVE AGREED TO BE BOUND BY
THE PROVISIONS OF A REGISTRATION RIGHTS AGREEMENT AMONG BALTIMORE GAS AND
ELECTRIC COMPANY AND THE INITIAL PURCHASERS, DATED OCTOBER 13, 2006 (THE “REGISTRATION
RIGHTS AGREEMENT”).  WE WILL PROVIDE
A COPY OF THE REGISTRATION RIGHTS AGREEMENT TO A HOLDER WITHOUT CHARGE UPON
WRITTEN REQUEST TO US AT OUR PRINCIPAL PLACE OF BUSINESS.


THIS SECURITY HAS
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES
ACT”), OR ANY STATE SECURITIES LAWS. 
NEITHER THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE
REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE
DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS
EXEMPT FROM, OR NOT SUBJECT TO, REGISTRATION.


THE HOLDER OF THIS
SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES TO OFFER, SELL OR OTHERWISE TRANSFER
SUCH SECURITY, PRIOR TO THE DATE (THE “RESALE RESTRICTION TERMINATION DATE”)
WHICH IS TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUE DATE HEREOF AND THE
LAST DATE ON WHICH BALTIMORE GAS AND ELECTRIC COMPANY (THE “COMPANY”) OR
ANY AFFILIATE OF THE COMPANY WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR
OF SUCH SECURITY), ONLY (I) TO THE COMPANY OR ANY SUBSIDIARY THEREOF, (II) FOR
SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A UNDER
THE SECURITIES ACT (“RULE 144A”), TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED
INSTITUTIONAL BUYER” AS DEFINED IN RULE l44A THAT PURCHASES FOR ITS OWN ACCOUNT
OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHICH NOTICE IS GIVEN
THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE l44A, (III) PURSUANT TO
OFFERS AND SALES TO NON U.S. PERSONS THAT OCCUR OUTSIDE THE UNITED STATES
WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT, (IV) PURSUANT TO A
REGISTRATION STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES
ACT, OR (V) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE REGISTRATION
REQUIREMENTS OF THE SECURITIES ACT (INCLUDING UNDER RULE 144 UNDER THE
SECURITIES ACT, IF AVAILABLE), SUBJECT TO THE COMPANY’S AND THE TRUSTEE’S RIGHT
PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER PURSUANT TO CLAUSES (III) OR (V) TO
REQUIRE THE 



 15
 






 



DELIVERY OF AN
OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO EACH
OF THEM, AND IN EACH OF THE FOREGOING CASES, A CERTIFICATE OF TRANSFER IN THE
FORM APPEARING ON THE OTHER SIDE OF THIS SECURITY IS COMPLETED AND DELIVERED BY
THE TRANSFEROR TO THE TRUSTEE.”


If Definitive Notes are
issued, each Definitive Note will bear the following additional legend:


“IN CONNECTION
WITH ANY TRANSFER, THE HOLDER WILL DELIVER TO THE REGISTRAR AND TRANSFER AGENT
SUCH CERTIFICATES AND OTHER INFORMATION AS SUCH TRANSFER AGENT MAY REASONABLY
REQUIRE TO CONFIRM THAT THE TRANSFER COMPLIES WITH THE FOREGOING RESTRICTIONS.”


Notwithstanding the
foregoing, any Global Note or Definitive Note issued pursuant to Sections
4.2(d), 4.3(b), 4.4(b), 4.4(c), 4.5(b), 4.5(c) or 4.6 (and all Notes issued in
exchange therefor or substitution thereof) shall not bear the Private Placement
Legend.


(b)           Global Note Legends.  Each Global
Note shall bear legends in substantially the following form:


“THIS GLOBAL NOTE IS
HELD BY THE DEPOSITARY (AS DEFINED IN THE INDENTURE GOVERNING THIS NOTE) OR ITS
NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT
TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (I) THE TRUSTEE
MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO SECTION 2.02 OF
THE INDENTURE, (II) THIS GLOBAL NOTE MAY BE EXCHANGED IN WHOLE BUT NOT IN PART
PURSUANT TO SECTION 4.1 OF THE FIRST SUPPLEMENTAL INDENTURE, (III) THIS GLOBAL
NOTE MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO SECTION 3.07
OF THE INDENTURE AND (IV) THIS GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR
DEPOSITARY WITH THE PRIOR WRITTEN CONSENT OF THE COMPANY.


UNLESS AND UNTIL
IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN DEFINITIVE FORM, THIS NOTE MAY
NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE
DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER
NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A
SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY. UNLESS THIS
CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”) TO THE
COMPANY OR ITS AGENT FOR 



 16
 






 



REGISTRATION OF
TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE
NAME OF CEDE & CO. OR SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO.  OR SUCH OTHER ENTITY AS MAY BE REQUESTED BY
AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF
FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.”


4.8           Cancellation
and/or Adjustment of Global Notes.  At such time
as all beneficial interests in a particular Global Note have been exchanged for
Definitive Notes or a particular Global Note has been redeemed, repurchased or
canceled in whole and not in part, each such Global Note shall be returned to
or retained and canceled by the Trustee in accordance with Section 3.07 of the
Indenture.  At any time prior to such
cancellation, if any beneficial interest in a Global Note is exchanged for or
transferred to a person who will take delivery thereof in the form of a
beneficial interest in another Global Note or for Definitive Notes, the
principal amount of Notes represented by such Global Note shall be reduced
accordingly and an endorsement shall be made on such Global Note by the Trustee
or by the Depositary at the direction of the Trustee to reflect such reduction;
and if the beneficial interest is being exchanged for or transferred to a
person who will take delivery thereof in the form of a beneficial interest in
another Global Note, such other Global Note shall be increased accordingly and
an endorsement shall be made on such Global Note by the Trustee or by the
Depositary at the direction of the Trustee to reflect such increase.


SECTION 5.           MISCELLANEOUS.


5.1           Ratification
of Indenture.  The Indenture, as supplemented by this First
Supplemental Indenture, is in all respects ratified and confirmed, and this First
Supplemental Indenture shall be deemed a part of the Indenture in the manner
and to the extent herein and therein provided.


5.2           GOVERNING LAW.  THIS FIRST SUPPLEMENTAL
INDENTURE, EACH NOTE AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES UNDER THIS FIRST
SUPPLEMENTAL INDENTURE AND EACH NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.


5.3           Counterparts. 
This First Supplemental Indenture may be executed in several
counterparts, each of which shall be an original, and all collectively but one
instrument.


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



 17















IN WITNESS WHEREOF, the parties hereto have caused
this First Supplemental Indenture to be executed as of the date first above
written.


	
   

  	
  BALTIMORE GAS AND ELECTRIC

  COMPANY, as Issuer

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Jeanne M. Blondia

  	
   

  
	
   

  	
   

  	
  Name:

  	
  Jeanne M. Blondia

  
	
   

  	
   

  	
  Title:

  	
  Treasurer and Assistant

  Secretary

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  DEUTSCHE BANK TRUST COMPANY

  AMERICAS,

  
	
   

  	
  as Trustee

  
	
   

  	
  By Deutsche Bank National Trust Company

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Yana Kalachikova

  	
   

  
	
   

  	
   

  	
  Name: Yana Kalachikova

  
	
   

  	
   

  	
  Title: Assistant Vice President

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ David Contino

  	
   

  
	
   

  	
   

  	
  Name: David Contino

  
	
   

  	
   

  	
  Title: Assistant Vice President

  
					



 















 


EXHIBIT A


[FACE OF 5.90% NOTE DUE 2016]


[Insert
Global Note Legends, if applicable pursuant to the provisions of the 

First Supplemental Indenture]


[Insert
the Private Placement Legend, if applicable pursuant to the provisions of the First
Supplemental Indenture]


	
  No.              

  	
  $                

  
	
   

  	
   

  
	
   

  	
  CUSIP:                  

  



 


BALTIMORE GAS AND ELECTRIC COMPANY


    % [Series A] [Series B] Notes
due       


	
  ORIGINAL ISSUE

  	
  INTEREST PAYMENT

  
	
  DATE:

  	
  DATES: April 1
  and October 1

  
	
   

  	
   

  
	
  INTEREST RATE: 5.90% per annum plus additional
  interest, if any, pursuant to the applicable Registration Rights Agreement
  (as defined below)

  	
   

  



 


MATURITY DATE: October 1,
2016


 


Baltimore Gas and Electric Company, a Maryland
corporation (together with its successors and assigns, the “Issuer”),
for value received, hereby promises to pay to                 ,
or registered assignees, the principal sum of                
on the Maturity Date specified above and to pay interest thereon at the
Interest Rate per annum specified above, semiannually in arrears on each
Interest Payment Date specified above during each year commencing on the
Interest Payment Date next succeeding the Original Issue Date specified above,
and at maturity (or on any redemption or repayment date).


Interest on this Note will accrue from the most recent
Interest Payment Date to which interest has been paid or duly provided for, or,
if no interest has been paid or duly provided for, from the Original Issue
Date, until the principal hereof has been paid or duly made available for
payment (except as provided below).  The
interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date will, subject to certain exceptions described herein, be paid to
the person in whose name this Note (or one or more predecessor Notes) is
registered at the close of business on the 15th day of the calendar 



 A-1
 






 



month prior to such
Interest Payment Date (whether or not a Business Day) (each such date a “Record
Date”); provided, however, that interest payable at maturity (or on any
redemption or repayment date) will be payable to the person to whom the
principal hereof shall be payable.  As
used herein, “Business Day” means any day, other than a Saturday or
Sunday, that is neither a legal holiday nor a day on which banking institutions
are authorized or required by law or executive order to close in Baltimore
Maryland or The City of New York.


The holder of this Note is entitled to the benefits of
the applicable Registration Rights Agreement (as defined in the First
Supplemental Indenture dated as of October 13, 2006 to the Indenture).


Payment of the principal of this Note, any premium and
the interest due at maturity (or on any redemption or repayment date) will be
made in immediately available funds upon surrender of this Note at the office
or agency of the Paying Agent, as defined on the reverse hereof, maintained for
that purpose in the Borough of Manhattan, The City of New York, or at such
other paying agency as the Issuer may determine.  Payment of the principal of and premium, if
any, and interest on this Note will be made by U.S. dollar check mailed to the
address of the person entitled thereto as such address shall appear in the Note
register.  A holder of U.S. $10,000,000 or
more in aggregate principal amount of Notes having the same Interest Payment
Date will be entitled to receive payments of interest, other than interest due
at maturity or on any date of redemption or repayment, by wire transfer of
immediately available funds if appropriate wire transfer instructions have been
received by the Paying Agent in writing not less than 15 calendar days prior to
the applicable Interest Payment Date.


Reference is hereby made to the further provisions of
this Note set forth on the reverse hereof; which further provisions shall for
all purposes have the same effect as if set forth at this place.


Unless the certificate of authentication hereon has
been executed by the Trustee referred to on the reverse hereof by manual
signature, this Note shall not be entitled to any benefit under the Indenture,
as defined on the reverse hereof, or be valid or obligatory for any purpose.



 A-2
 






 



IN WITNESS WHEREOF, the Issuer has caused this Note to
be duly executed under its corporate seal.


DATED:


	
   

  	
  BALTIMORE GAS AND ELECTRIC

  COMPANY

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
  ATTEST:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  
				



 


TRUSTEE’S
CERTIFICATE

OF AUTHENTICATION


This is one of the Notes referred

to in the within-mentioned Indenture.


	
   

  	
  DEUTSCHE
  BANK TRUST COMPANY

  AMERICAS,

  
	
   

  	
  as Trustee

  
	
   

  	
  By Deutsche Bank National Trust Company

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 



 A-3
 






 



[BACK OF 5.90% NOTE
DUE 2016]


This Note is one of a duly authorized issue of 5.90% Series
[A][B] Notes due 2016 (the “Notes”) of the Issuer.  The Notes are issuable under an indenture,
dated as of July 24, 2006 (as amended by the First Supplemental Indenture dated
as of October 13, 2006, the “Indenture”), each between the Issuer and Deutsche
Bank Trust Company Americas, as Trustee (the “Trustee,” which term
includes any successor trustee under the Indenture), to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the
respective rights, limitations of rights, duties and immunities of the Issuer,
the Trustee and holders of the Notes and the terms upon which the Notes are,
and are to be, authenticated and delivered. 
The Issuer has appointed Deutsche Bank Trust Company Americas, at its
principal corporate trust office in The City of New York as the paying agent
(the “Paying Agent,” which term includes any additional or successor
Paying Agent appointed by the Issuer) with respect to the Notes.  To the extent not inconsistent herewith, the
terms of the Indenture are hereby incorporated by reference herein.


This Note may be redeemed in whole or in part at the
option of the Issuer upon payment of the redemption price specified below.  If the Issuer exercises the option to redeem
this Note, the redemption price will equal the greater of (i) 100% of the
principal amount of this Note or (ii) the sum, as determined by the Independent
Investment Banker (defined below), of the present value of the principal amount
of this Note and the remaining scheduled payments of interest on this Note from
the redemption date to the Maturity Date, exclusive of interest accrued to the
redemption date (the “Remaining Life”), discounted from the scheduled payment
dates to the redemption date on a semiannual basis (assuming a 360-day year of
30-day months) at the Treasury Yield (defined below) plus 20 basis points, plus
accrued and unpaid interest on the principal amount being redeemed to the date
of redemption.  Notice of redemption
shall be mailed to the registered holders of the Notes designated for
redemption at their addresses as the same shall appear on the Note register not
less than 30 nor more than 60 days prior to the date fixed for redemption,
subject to all the conditions and provisions of the Indenture.  In the event of redemption of this Note in
part only, a new Note or Notes for the amount of the unredeemed portion hereof
shall be issued in the name of the holder hereof upon the cancellation hereof.


If the Issuer fails to deposit the redemption price
with the Trustee on or prior to the redemption date, then notwithstanding any
notice of redemption that has been given as provided in Section 4.04 of the
Indenture, the Notes or portions of Notes with respect to which such notice has
been given shall not become due and payable on the date and at the place or
places stated in such notice.  In
addition, the failure to redeem the Notes shall not constitute a default or
Event of Default pursuant to Section 7.01 of the Indenture.


For purposes of the immediately preceding paragraph,
the following defined terms shall have the meanings specified:


“Independent Investment Banker” means Merrill Lynch,
Pierce Fenner & Smith Incorporated if (1) the Issuer does not appoint
someone else at least 30 days prior to such redemption date or (2) such other
institution appointed by the Issuer is unwilling or unable to calculate the redemption
price.  If Merrill Lynch, Pierce Fenner
& Smith Incorporated is 



 A-4
 






 



unwilling or unable to
calculate the redemption price, then the Trustee shall appoint an independent
investment banking institution of national standing to make the calculation.


“Treasury Yield” means, with respect to any redemption
date, the rate determined by the Independent Investment Banker from the most
recent statistical release published by the Federal Reserve Bank of New York
entitled “H.15(519) Selected Interest Rate” or any successor publication as
follows: (i) if the H.15 Statistical Release gives a weekly average yield for
United States Treasury Notes having a constant maturity that is the same as the
Remaining Life of the Notes, then the Treasury Yield will equal that weekly
average yield and (ii) in all other cases, the Independent Investment Banker
will calculate the Treasury Yield by interpolating, on a straight line basis,
the weekly average yields from the H.15 Statistical Release on the United
States Treasury Notes having a constant maturity closest to but greater than
the Remaining Life of the Notes and the United States Treasury Notes having a
constant maturity closest to and less than the Remaining Life of the Notes. The
Independent Investment Banker shall round any weekly average yields calculated
by interpolation to the nearest 1/100th of 1% and shall round the percentage up for
any figure of 1/200th of
1% or above. If weekly average yields for United States Treasury Notes are not
available in the H.15 Statistical Release, or anywhere else, the Independent
Investment Banker shall select comparable rates and calculate the Treasury
Yield using such rates.


Interest payments on this Note will include interest
accrued to but excluding the Interest Payment Dates or the Maturity Date (or
any earlier redemption or repayment date), as the case may be.  Interest payments for this Note will be computed
and paid on the basis of a 360-day year of twelve 30-day months.


In the case where the Interest Payment Date or the
Maturity Date (or any redemption or repayment date) does not fall on a Business
Day, payment of interest, premium, if any, or principal otherwise payable on
such date need not be made on such date, but may be made on the next succeeding
Business Day with the same force and effect as if made on the Interest Payment
Date or on the Maturity Date (or any redemption or repayment date), and no
interest on such payment shall accrue for the period from and after the
Interest Payment Date or the Maturity Date (or any redemption or repayment
date) to such next succeeding Business Day.


This Note and all the obligations of the Issuer
hereunder are direct, unsecured obligations of the Issuer and rank without
preference or priority among themselves and pari passu with all other existing
and future unsecured and unsubordinated indebtedness of the Issuer, subject to
certain statutory exceptions in the event of liquidation upon insolvency.


This Note, and any Note or Notes issued upon
registration of transfer or exchange hereof, is issuable only in fully
registered form, without coupons, and is issuable only in denominations of U.S.
$1,000 and any integral multiple of U.S. $1,000 in excess thereof.


The Trustee has been appointed registrar for the
Notes, and the Trustee will maintain at its principal corporate trust office in
The City of New York a register for the registration and transfer of
Notes.  This Note may be transferred at
the aforesaid office of 



 A-5
 






 



the Trustee by
surrendering this Note for cancellation, accompanied by a written instrument of
transfer in form satisfactory to the Trustee and duly executed by the
registered holder hereof in person or by the holder’s attorney duly authorized
in writing, and thereupon the Trustee shall issue in the name of the transferee
or transferees, in exchange herefor, a new Note or Notes having identical terms
and provisions and having a like aggregate principal amount in authorized
denominations, subject to the terms and conditions set forth herein; provided,
however, that the Trustee will not be required (i) to register the
transfer of or exchange any Note that has been called for redemption in whole
or in part, except the unredeemed portion of Notes being redeemed in part, (ii)
to register the transfer of or exchange any Note if the holder thereof has
exercised his right, if any, to require the Issuer to repurchase such Note in
whole or in part, except the portion of such Note not required to be repurchased,
or (iii) to register the transfer of or exchange Notes to the extent and during
the period so provided in the Indenture with respect to the redemption of
Notes.  Notes are exchangeable at said
office for other Notes of other authorized denominations of equal aggregate
principal amount having identical terms and provisions.  All such exchanges and transfers of Notes
will be free of charge, but the Issuer or the Trustee may require payment of a
sum sufficient to cover any tax or other governmental charge in connection
therewith.  All Notes surrendered for
exchange shall be accompanied by a written instrument of transfer in form
satisfactory to the Trustee and executed by the registered holder in person or
by the holder’s attorney duly authorized in writing.  The date of registration of any Note
delivered upon any exchange or transfer of Notes shall be such that no gain or
loss of interest results from such exchange or transfer.


In case any Note shall at any time become mutilated,
defaced or be destroyed, lost or stolen and such Note or evidence of the loss,
theft or destruction thereof (together with the indemnity hereinafter referred
to and such other documents or proof as may be required in the premises) shall
be delivered to the Trustee, a new Note of like tenor will be issued by the
Issuer in exchange for the Note so mutilated or defaced, or in lieu of the Note
so destroyed or lost or stolen, but, in the case of any destroyed or lost or
stolen Note, only upon receipt of evidence satisfactory to the Trustee and the
Issuer that such Note was destroyed or lost or stolen and, if required, upon
receipt also of indemnity satisfactory to each of them.  All expenses and reasonable charges
associated with procuring such indemnity and with the preparation, authentication
and delivery of a new Note shall be borne by the owner of the Note mutilated,
defaced, destroyed, lost or stolen.


So long as this Note shall be outstanding, the Issuer
will cause to be maintained an office or agency for the payment of the
principal of and premium, if any, and interest on this Note as herein provided
in the Borough of Manhattan, The City of New York, and an office or agency in
said Borough of Manhattan for the registration, transfer and exchange as
aforesaid of the Notes.  The Issuer may designate
other agencies for the payment of said principal, premium and interest at such
place or places (subject to applicable laws and regulations) as the Issuer may
decide.  So long as there shall be such
an agency, the Issuer shall keep the Trustee advised of the names and locations
of such agencies, if any are so designated.


With respect to moneys paid by the Issuer and held by
the Trustee or any Paying Agent for payment of the principal of or interest or
premium, if any, on any Notes that 



 A-6
 






 



remain unclaimed at the
end of two years after such principal, interest or premium shall have become
due and payable (whether at maturity or upon call for redemption or otherwise),
(i) the Trustee or such Paying Agent shall notify the holders of such Notes
that such moneys shall be repaid to the Issuer and any person claiming such
moneys shall thereafter look only to the Issuer for payment thereof and (ii)
such moneys shall be so repaid to the Issuer. 
Upon such repayment all liability of the Trustee or such Paying Agent
with respect to such moneys shall thereupon cease, without, however, limiting
in any way any obligation that the Issuer may have to pay the principal of or
interest or premium, if any, on this Note as the same shall become due.


No provision of this Note or of the Indenture shall
alter or impair the obligation of the Issuer, which is absolute and
unconditional, to pay the principal of, premium, if any, and interest on this
Note at the time, place and rate, and in the coin and currency, herein prescribed
unless otherwise agreed between the Issuer and the registered holder of this
Note.


Prior to due presentment of this Note for registration
of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee
may treat the holder in whose name this Note is registered as the owner hereof
for all purposes, whether or not this Note be overdue, and none of the Issuer,
the Trustee or any such agent shall be affected by notice to the contrary.


No recourse under or upon any obligation, covenant or
agreement contained in the Indenture, or in this Note, or because of the
indebtedness evidenced hereby, shall be had against any incorporator, as such,
or against any past, present or future stockholder, officer or director, as
such, of the Issuer or of any successor, either directly or through the Issuer
or any successor, under any rule of law, statute or constitutional provision or
by the enforcement of any assessment or by any legal or equitable proceeding or
otherwise, all such liability being, by the acceptance hereof and as part of
the consideration for the issuance hereof, expressly waived and released.


This Note shall for all purposes be governed by, and
construed in accordance with, the laws of the State of New York.


All terms used in this Note which are defined in the
Indenture and not otherwise defined herein shall have the meanings assigned to
them in the Indenture.



 A-7
 






 



Assignment Form


	
  To assign this Note, fill in
  the form below: (I) or (we) assign and transfer this Note to

  
	
  (Insert assignee’s soc. sec. or tax I.D. no.)

  
	
   

  



 


 


 


 


(Print or type assignee’s
name, address and zip code)


and irrevocably appoint


	
  to transfer this Note on the books of the
  Issuer. The agent may substitute another to act for him.

  
	
   

  



 


Date:


Your Signature:


(Sign exactly as
your name appears on the face of this Note)


Tax Identification
No:


	
  SIGNATURE GUARANTEE:

  
	
   

  
	
   

  



                


Signatures must be
guaranteed by an “eligible guarantor institution” meeting the requirements of
the Registrar, which requirements include membership or participation in the
Security Transfer Agent Medallion Program (“STAMP”) or such
other “signature guarantee program” as may be determined by the Registrar in
addition to, or in substitution for, STAMP, all in accordance with the
Securities Exchange Act of 1934, as amended.



 A-8
 






 



SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL NOTE(1)


The following exchanges of a part of this Global Note
for an interest in another Global Note or for a Definitive Note, or exchanges
of a part of another Global Note or Definitive Note for an interest in this
Global Note, have been made:


	
  Date of

  Exchange

  	
   

  	
  Amount of

  decrease in

  Principal Amount

  of this Global

  Note

  	
   

  	
  Amount of

  increase in

  Principal Amount

  of this Global Note

  	
   

  	
  Principal Amount

  of this Global

  Note following

  such decrease (or

  increase)

  	
   

  	
  Signature of

  authorized officer

  of Trustee

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  



 






(1) This should be
included only if the Note is issued in global form.



 A-9














 


EXHIBIT B


[FACE OF 6.35% NOTE DUE 2036]


[Insert
Global Note Legends, if applicable pursuant to the provisions of the 

First Supplemental Indenture]


[Insert
the Private Placement Legend, if applicable pursuant to the provisions of the
First Supplemental Indenture]


 


	
  No.              

  	
  $                

  
	
   

  	
  CUSIP:                

  



 


BALTIMORE GAS AND ELECTRIC COMPANY


    % [Series A] [Series B] Notes
due       


	
  ORIGINAL ISSUE

  	
  INTEREST PAYMENT

  
	
  DATE:

  	
  DATES: April 1 and
  October 1

  
	
   

  	
   

  
	
  INTEREST RATE: 6.35% per annum plus additional
  interest, if any, pursuant to the applicable Registration Rights Agreement
  (as defined below)

  	
   

  



 


MATURITY DATE: October 1, 2036


Baltimore Gas and Electric Company, a Maryland
corporation (together with its successors and assigns, the “Issuer”),
for value received, hereby promises to pay to                 ,
or registered assignees, the principal sum of                
on the Maturity Date specified above and to pay interest thereon at the Interest
Rate per annum specified above, semiannually in arrears on each Interest
Payment Date specified above during each year commencing on the Interest
Payment Date next succeeding the Original Issue Date specified above, and at
maturity (or on any redemption or repayment date).


Interest on this Note will accrue from the most recent
Interest Payment Date to which interest has been paid or duly provided for, or,
if no interest has been paid or duly provided for, from the Original Issue
Date, until the principal hereof has been paid or duly made available for
payment (except as provided below).  The
interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date will, subject to certain exceptions described herein, be paid to
the person in whose name this Note (or one or more predecessor Notes) is
registered at the close of business on the 15th day of the calendar 



 B-1
 






 



month prior to such
Interest Payment Date (whether or not a Business Day) (each such date a “Record
Date”); provided, however, that interest payable at maturity (or on any
redemption or repayment date) will be payable to the person to whom the
principal hereof shall be payable.  As
used herein, “Business Day” means any day, other than a Saturday or
Sunday, that is neither a legal holiday nor a day on which banking institutions
are authorized or required by law or executive order to close in Baltimore
Maryland or The City of New York.


The holder of this Note is entitled to the benefits of
the applicable Registration Rights Agreement (as defined in the First
Supplemental Indenture dated as of October 13, 2006 to the Indenture).


Payment of the principal of this Note, any premium and
the interest due at maturity (or on any redemption or repayment date) will be
made in immediately available funds upon surrender of this Note at the office
or agency of the Paying Agent, as defined on the reverse hereof, maintained for
that purpose in the Borough of Manhattan, The City of New York, or at such
other paying agency as the Issuer may determine.  Payment of the principal of and premium, if
any, and interest on this Note will be made by U.S. dollar check mailed to the
address of the person entitled thereto as such address shall appear in the Note
register.  A holder of U.S. $10,000,000
or more in aggregate principal amount of Notes having the same Interest Payment
Date will be entitled to receive payments of interest, other than interest due
at maturity or on any date of redemption or repayment, by wire transfer of
immediately available funds if appropriate wire transfer instructions have been
received by the Paying Agent in writing not less than 15 calendar days prior to
the applicable Interest Payment Date.


Reference is hereby made to the further provisions of
this Note set forth on the reverse hereof; which further provisions shall for
all purposes have the same effect as if set forth at this place.


Unless the certificate of authentication hereon has
been executed by the Trustee referred to on the reverse hereof by manual
signature, this Note shall not be entitled to any benefit under the Indenture,
as defined on the reverse hereof, or be valid or obligatory for any purpose.



 B-2
 






 



IN WITNESS WHEREOF, the Issuer has caused this Note to
be duly executed under its corporate seal.


DATED:


	
   

  	
  BALTIMORE
  GAS AND ELECTRIC

  
	
   

  	
  COMPANY

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  
	
   

  	
   

  	
   

  
	
   

  	
  ATTEST:

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  



 


TRUSTEE’S
CERTIFICATE

OF AUTHENTICATION


This is one of the Notes referred

to in the within-mentioned Indenture.


	
   

  	
  DEUTSCHE
  BANK TRUST COMPANY

  AMERICAS,

  
	
   

  	
  as Trustee

  
	
   

  	
  By Deutsche Bank National Trust Company

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 



 B-3
 






 



[BACK OF 6.35%
NOTE DUE 2036]


This Note is one of a duly authorized issue of 6.35%%
Series [A][B] Notes due 2036 (the “Notes”) of the Issuer.  The Notes are issuable under an indenture,
dated as of July 24, 2006 (as amended by the First Supplemental Indenture dated
as of October 13, 2006, the “Indenture”), each between the Issuer and
Deutsche Bank Trust Company Americas, as Trustee (the “Trustee,” which
term includes any successor trustee under the Indenture), to which Indenture
and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and
immunities of the Issuer, the Trustee and holders of the Notes and the terms
upon which the Notes are, and are to be, authenticated and delivered.  The Issuer has appointed Deutsche Bank Trust
Company Americas, at its principal corporate trust office in The City of New
York as the paying agent (the “Paying Agent,” which term includes any
additional or successor Paying Agent appointed by the Issuer) with respect to
the Notes.  To the extent not
inconsistent herewith, the terms of the Indenture are hereby incorporated by
reference herein.


This Note may be redeemed in whole or in part at the
option of the Issuer upon payment of the redemption price specified below.  If the Issuer exercises the option to redeem
this Note, the redemption price will equal the greater of (i) 100% of the
principal amount of this Note or (ii) the sum, as determined by the Independent
Investment Banker (defined below), of the present value of the principal amount
of this Note and the remaining scheduled payments of interest on this Note from
the redemption date to the Maturity Date, exclusive of interest accrued to the
redemption date (the “Remaining Life”), discounted from the scheduled payment
dates to the redemption date on a semiannual basis (assuming a 360-day year of
30-day months) at the Treasury Yield (defined below) plus 25 basis points, plus
accrued and unpaid interest on the principal amount being redeemed to the date
of redemption.  Notice of redemption
shall be mailed to the registered holders of the Notes designated for
redemption at their addresses as the same shall appear on the Note register not
less than 30 nor more than 60 days prior to the date fixed for redemption,
subject to all the conditions and provisions of the Indenture.  In the event of redemption of this Note in
part only, a new Note or Notes for the amount of the unredeemed portion hereof
shall be issued in the name of the holder hereof upon the cancellation hereof.


If the Issuer fails to deposit the redemption price
with the Trustee on or prior to the redemption date, then notwithstanding any
notice of redemption that has been given as provided in Section 4.04 of the
Indenture, the Notes or portions of Notes with respect to which such notice has
been given shall not become due and payable on the date and at the place or
places stated in such notice.  In
addition, the failure to redeem the Notes shall not constitute a default or
Event of Default pursuant to Section 7.01 of the Indenture.


For purposes of the immediately preceding paragraph,
the following defined terms shall have the meanings specified:


“Independent Investment Banker” means Merrill Lynch,
Pierce Fenner & Smith Incorporated if (1) the Issuer does not appoint
someone else at least 30 days prior to such redemption date or (2) such other
institution appointed by the Issuer is unwilling or unable to calculate the
redemption price.  If Merrill Lynch,
Pierce Fenner & Smith Incorporated is 



 B-4
 






 



unwilling or unable to
calculate the redemption price, then the Trustee shall appoint an independent
investment banking institution of national standing to make the calculation.


“Treasury Yield” means, with respect to any redemption
date, the rate determined by the Independent Investment Banker from the most
recent statistical release published by the Federal Reserve Bank of New York
entitled “H.15(519) Selected Interest Rate” or any successor publication as
follows: (i) if the H.15 Statistical Release gives a weekly average yield for
United States Treasury Notes having a constant maturity that is the same as the
Remaining Life of the Notes, then the Treasury Yield will equal that weekly
average yield and (ii) in all other cases, the Independent Investment Banker
will calculate the Treasury Yield by interpolating, on a straight line basis,
the weekly average yields from the H.15 Statistical Release on the United
States Treasury Notes having a constant maturity closest to but greater than
the Remaining Life of the Notes and the United States Treasury Notes having a
constant maturity closest to and less than the Remaining Life of the Notes. The
Independent Investment Banker shall round any weekly average yields calculated
by interpolation to the nearest 1/100th of 1% and shall round the percentage up for
any figure of 1/200th of
1% or above. If weekly average yields for United States Treasury Notes are not
available in the H.15 Statistical Release, or anywhere else, the Independent
Investment Banker shall select comparable rates and calculate the Treasury
Yield using such rates.


Interest payments on this Note will include interest
accrued to but excluding the Interest Payment Dates or the Maturity Date (or
any earlier redemption or repayment date), as the case may be.  Interest payments for this Note will be computed
and paid on the basis of a 360-day year of twelve 30-day months.


In the case where the Interest Payment Date or the
Maturity Date (or any redemption or repayment date) does not fall on a Business
Day, payment of interest, premium, if any, or principal otherwise payable on
such date need not be made on such date, but may be made on the next succeeding
Business Day with the same force and effect as if made on the Interest Payment
Date or on the Maturity Date (or any redemption or repayment date), and no
interest on such payment shall accrue for the period from and after the
Interest Payment Date or the Maturity Date (or any redemption or repayment
date) to such next succeeding Business Day.


This Note and all the obligations of the Issuer
hereunder are direct, unsecured obligations of the Issuer and rank without
preference or priority among themselves and pari passu with all other existing
and future unsecured and unsubordinated indebtedness of the Issuer, subject to
certain statutory exceptions in the event of liquidation upon insolvency.


This Note, and any Note or Notes issued upon
registration of transfer or exchange hereof, is issuable only in fully
registered form, without coupons, and is issuable only in denominations of U.S.
$1,000 and any integral multiple of U.S. $1,000 in excess thereof.


The Trustee has been appointed registrar for the
Notes, and the Trustee will maintain at its principal corporate trust office in
The City of New York a register for the registration and transfer of
Notes.  This Note may be transferred at
the aforesaid office of 



 B-5
 






 



the Trustee by
surrendering this Note for cancellation, accompanied by a written instrument of
transfer in form satisfactory to the Trustee and duly executed by the
registered holder hereof in person or by the holder’s attorney duly authorized
in writing, and thereupon the Trustee shall issue in the name of the transferee
or transferees, in exchange herefor, a new Note or Notes having identical terms
and provisions and having a like aggregate principal amount in authorized
denominations, subject to the terms and conditions set forth herein; provided,
however, that the Trustee will not be required (i) to register the
transfer of or exchange any Note that has been called for redemption in whole
or in part, except the unredeemed portion of Notes being redeemed in part, (ii)
to register the transfer of or exchange any Note if the holder thereof has
exercised his right, if any, to require the Issuer to repurchase such Note in
whole or in part, except the portion of such Note not required to be repurchased,
or (iii) to register the transfer of or exchange Notes to the extent and during
the period so provided in the Indenture with respect to the redemption of
Notes.  Notes are exchangeable at said
office for other Notes of other authorized denominations of equal aggregate
principal amount having identical terms and provisions.  All such exchanges and transfers of Notes
will be free of charge, but the Issuer or the Trustee may require payment of a
sum sufficient to cover any tax or other governmental charge in connection
therewith.  All Notes surrendered for
exchange shall be accompanied by a written instrument of transfer in form
satisfactory to the Trustee and executed by the registered holder in person or
by the holder’s attorney duly authorized in writing.  The date of registration of any Note delivered
upon any exchange or transfer of Notes shall be such that no gain or loss of
interest results from such exchange or transfer.


In case any Note shall at any time become mutilated,
defaced or be destroyed, lost or stolen and such Note or evidence of the loss,
theft or destruction thereof (together with the indemnity hereinafter referred
to and such other documents or proof as may be required in the premises) shall
be delivered to the Trustee, a new Note of like tenor will be issued by the
Issuer in exchange for the Note so mutilated or defaced, or in lieu of the Note
so destroyed or lost or stolen, but, in the case of any destroyed or lost or
stolen Note, only upon receipt of evidence satisfactory to the Trustee and the
Issuer that such Note was destroyed or lost or stolen and, if required, upon
receipt also of indemnity satisfactory to each of them.  All expenses and reasonable charges
associated with procuring such indemnity and with the preparation, authentication
and delivery of a new Note shall be borne by the owner of the Note mutilated,
defaced, destroyed, lost or stolen.


So long as this Note shall be outstanding, the Issuer
will cause to be maintained an office or agency for the payment of the
principal of and premium, if any, and interest on this Note as herein provided
in the Borough of Manhattan, The City of New York, and an office or agency in
said Borough of Manhattan for the registration, transfer and exchange as
aforesaid of the Notes.  The Issuer may
designate other agencies for the payment of said principal, premium and
interest at such place or places (subject to applicable laws and regulations)
as the Issuer may decide.  So long as
there shall be such an agency, the Issuer shall keep the Trustee advised of the
names and locations of such agencies, if any are so designated.


With respect to moneys paid by the Issuer and held by
the Trustee or any Paying Agent for payment of the principal of or interest or
premium, if any, on any Notes that 



 B-6
 






 



remain unclaimed at the
end of two years after such principal, interest or premium shall have become
due and payable (whether at maturity or upon call for redemption or otherwise),
(i) the Trustee or such Paying Agent shall notify the holders of such Notes
that such moneys shall be repaid to the Issuer and any person claiming such
moneys shall thereafter look only to the Issuer for payment thereof and (ii)
such moneys shall be so repaid to the Issuer. 
Upon such repayment all liability of the Trustee or such Paying Agent
with respect to such moneys shall thereupon cease, without, however, limiting
in any way any obligation that the Issuer may have to pay the principal of or
interest or premium, if any, on this Note as the same shall become due.


No provision of this Note or of the Indenture shall
alter or impair the obligation of the Issuer, which is absolute and
unconditional, to pay the principal of, premium, if any, and interest on this
Note at the time, place and rate, and in the coin and currency, herein prescribed
unless otherwise agreed between the Issuer and the registered holder of this
Note.


Prior to due presentment of this Note for registration
of transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee
may treat the holder in whose name this Note is registered as the owner hereof
for all purposes, whether or not this Note be overdue, and none of the Issuer,
the Trustee or any such agent shall be affected by notice to the contrary.


No recourse under or upon any obligation, covenant or
agreement contained in the Indenture, or in this Note, or because of the
indebtedness evidenced hereby, shall be had against any incorporator, as such,
or against any past, present or future stockholder, officer or director, as
such, of the Issuer or of any successor, either directly or through the Issuer
or any successor, under any rule of law, statute or constitutional provision or
by the enforcement of any assessment or by any legal or equitable proceeding or
otherwise, all such liability being, by the acceptance hereof and as part of
the consideration for the issuance hereof, expressly waived and released.


This Note shall for all purposes be governed by, and
construed in accordance with, the laws of the State of New York.


All terms used in this Note which are defined in the
Indenture and not otherwise defined herein shall have the meanings assigned to
them in the Indenture.



 B-7
 






 



Assignment Form


	
  To assign this Note, fill in
  the form below:  (I) or (we) assign and
  transfer this Note to

  
	
  (Insert assignee’s soc. sec. or tax I.D. no.)

  
	
   

  



 


 


 


 


(Print or type assignee’s
name, address and zip code)


and irrevocably appoint


	
  to transfer this Note on the books of the
  Issuer.  The agent may substitute
  another to act for him.

  



 


Date:


Your Signature:


(Sign exactly as
your name appears on the face of this Note)


Tax Identification
No:


	
  SIGNATURE GUARANTEE:

  
	
   

  
	
   

  



 


Signatures must be
guaranteed by an “eligible guarantor institution” meeting the requirements of
the Registrar, which requirements include membership or participation in the
Security Transfer Agent Medallion Program (“STAMP”) or such
other “signature guarantee program” as may be determined by the Registrar in
addition to, or in substitution for, STAMP, all in accordance with the
Securities Exchange Act of 1934, as amended.



 B-8
 






 



SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL NOTE(2)


The following exchanges of a part of this Global Note
for an interest in another Global Note or for a Definitive Note, or exchanges
of a part of another Global Note or Definitive Note for an interest in this
Global Note, have been made:


	
  Date of

  Exchange

  	
   

  	
  Amount of

  decrease in

  Principal Amount

  of this Global

  Note

  	
   

  	
  Amount of

  increase in

  Principal Amount

  of this Global Note

  	
   

  	
  Principal Amount

  of this Global

  Note following

  such decrease (or

  increase)

  	
   

  	
  Signature of

  authorized officer

  of Trustee

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
    

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  



 


 






(2) This should be included only if the Note is issued
in global form.



 B-9















EXHIBIT C


[FORM OF CERTIFICATE OF TRANSFER]


Baltimore Gas and Electric Company


750 East Pratt Street


Baltimore, MD 21202


Attention:              Secretary
of the Company


Deutsche Bank Trust Company Americas


60 Wall Street, 27th Floor


New York, NY 10005

Attention: Trust and Securities Services


Re:  [    ]% Series [A][B] Notes
due [        ]


Reference
is hereby made to the Indenture, dated as of July 24, 2006, as amended by the First
Supplemental Indenture, dated as of October 13, 2006 (as so amended and
supplemented, the “Indenture”),
between Baltimore Gas and Electric Company, a Maryland corporation, as issuer
(the “Company”), and Deutsche Bank Trust
Company Americas, as trustee. 
Capitalized terms used but not defined herein shall have the meanings
given to them in the Indenture.


                   ,
(the “Transferor”) owns and proposes to
transfer the Note[s] or interest in such Note[s] specified in Annex A hereto,
in the principal amount of $                   
in such Note[s] or interests (the “Transfer”), to                    
(the “Transferee”), as further specified in
Annex A hereto.  In connection with the
Transfer, the Transferor hereby certifies that:


[CHECK ALL THAT APPLY]


1.                                       o  Check if Transferee will take delivery of a beneficial interest in a
Restricted Global Note or a Restricted Definitive Note Pursuant to Rule 144A.  The Transfer is being effected pursuant to
and in accordance with Rule l44A under the United States Securities Act of
1933, as amended (the “Securities Act”),
and, accordingly, the Transferor hereby further certifies that the beneficial
interest or Restricted Definitive Note is being transferred to a person that
the Transferor reasonably believed and believes is purchasing the beneficial
interest or Restricted Definitive Note for its own account, or for one or more
accounts with respect to which such person exercises sole investment
discretion, and such person and each such account is a “qualified institutional
buyer” within the meaning of Rule 144A in a transaction meeting the
requirements of Rule 144A and such Transfer is in compliance with any
applicable blue sky securities laws of any state of the United States.  Upon consummation of the proposed Transfer in
accordance with the terms of the Indenture, the transferred beneficial interest
or Restricted Definitive Note



 C-1
 






 



will be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the Restricted Global Note and/or the Restricted Definitive Note and in the
Indenture and the Securities Act.


2.                                       o  Check if Transferee will take delivery of a beneficial interest in a
Restricted Global Note or a Restricted Definitive Note Pursuant to Regulation S.  The Transfer is being effected pursuant to
and in accordance with Rule 903 or Rule 904 under the Securities Act and,
accordingly, the Transferor hereby further certifies that (i) the Transfer is
not being made to a person in the United States and (x) at the time the buy
order was originated, the Transferee was outside the United States or such
Transferor and any person acting on its behalf reasonably believed and believes
that the Transferee was outside the United States or (y) the transaction was
executed in, on or through the facilities of a designated offshore securities
market and neither such Transferor nor any person acting on its behalf knows
that the transaction was prearranged with a buyer in the United States, (ii) no
directed selling efforts have been made in contravention of the requirements of
Rule 903(b) or Rule 904(b) of Regulation S under the Securities Act and (iii)
the transaction is not part of a plan or scheme to evade the registration
requirements of the Securities Act.  Upon
consummation of the proposed transfer in accordance with the terms of the
Indenture, the transferred beneficial interest or Restricted Definitive Note
will be subject to the restrictions on transfer enumerated in the Private
Placement Legend printed on the Restricted Global Note and/or the Restricted
Definitive Note and in the Indenture and the Securities Act.


3.                                       o  Check and complete if Transferee will take delivery of a beneficial
interest in a Definitive Note pursuant to any provision of the Securities Act
other than Rule 144A or Regulation S.  The Transfer is being effected in compliance
with the transfer restrictions applicable to beneficial interests in Restricted
Global Notes and Restricted Definitive Notes and pursuant to and in accordance
with the Securities Act and any applicable blue sky securities laws of any
state of the United States, and accordingly the Transferor hereby further
certifies that (check one):


(a)           o 
such Transfer is being effected pursuant to and in accordance with Rule
144 under the Securities Act;


or


(b)           o 
such Transfer is being effected to the Company or a subsidiary thereof;


or



 C-2
 






 



(c)           o 
such Transfer is being effected pursuant to an effective registration
statement under the Securities Act and in compliance with the prospectus
delivery requirements of the Securities Act.


4.                                       o  Check if Transferee will take delivery of a beneficial interest in an
Unrestricted Global Note or of an Unrestricted Definitive Note.


(a)           o  Check if Transfer is pursuant to Rule 144.  (i) The Transfer is being effected pursuant
to and in accordance with Rule 144 under the Securities Act and in compliance
with the transfer restrictions contained in the Indenture and any applicable
blue sky securities laws of any state of the United States and (ii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act.  Upon consummation of the proposed
Transfer in accordance with the terms of the Indenture, the transferred
beneficial interest or Definitive Note will no longer be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the Restricted Global Notes, on Restricted Definitive Notes and in the
Indenture.


(b)           o  Check if Transfer is Pursuant to Regulation S.  (i) The Transfer is being effected pursuant
to and in accordance with Rule 903 or Rule 904 under the Securities Act and in
compliance with the transfer restrictions contained in the Indenture and any
applicable blue sky securities laws of any state of the United States and (ii)
the restrictions on transfer contained in the Indenture and the Private
Placement Legend are not required in order to maintain compliance with the
Securities Act.  Upon consummation of the
proposed Transfer in accordance with the terms of the Indenture, the
transferred beneficial interest or Definitive Note will no longer be subject to
the restrictions on transfer enumerated in the Private Placement Legend printed
on the Restricted Global Notes, on Restricted Definitive Notes and in the
Indenture.


(c)           o  Check if Transfer is Pursuant to Other Exemption.  (i) The Transfer is being effected pursuant
to and in compliance with an exemption from the registration requirements of
the Securities Act other than Rule 144, Rule 903 or Rule 904 and in compliance
with the transfer restrictions contained in the Indenture and any applicable
blue sky securities laws of any State of the United States and (ii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act.  Upon consummation of the proposed
Transfer in accordance with the terms of the Indenture, the transferred
beneficial interest or Definitive Note will not be subject to the restrictions
on transfer enumerated in the Private Placement Legend printed on the
Restricted Global Notes or Restricted Definitive Notes and in the Indenture.


This
certificate and the statements contained herein are made for your benefit and
the benefit of the Company.



 C-3
 






 



 


	
   

  	
   

  	
   

  
	
  

  	
    [Insert
  Name of Transferor]

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
  Dated:

  	
   

  	
  ,

  	
   

  	
   

  	
   

  
								



 



 C-4
 






 



ANNEX A TO
CERTIFICATE OF TRANSFER


1.             The Transferor owns and proposes to transfer the
following:


[CHECK ONE OF (a) OR (b)]


(a)           o  a
beneficial interest in the Restricted Global Note; or


(b)           o  a
Restricted Definitive Note.


2.             After the Transfer the Transferee will hold:


[CHECK ONE]


(a)           o  a
beneficial interest in the:


(i)            o 
Restricted Global Note (CUSIP             ),
or


(ii)           o 
Unrestricted Global Note (CUSIP             );
or


(b)           o 
Restricted Definitive Note; or


(c)           o 
an Unrestricted Definitive Note,


in
accordance with the terms of the Indenture.



 C-5















EXHIBIT D


[FORM OF CERTIFICATE OF EXCHANGE]


Baltimore Gas and Electric Company


750 East Pratt Street


Baltimore, MD 21202


Attention:              Secretary
of the Company


Deutsche Bank Trust Company Americas


60 Wall Street, 27th Floor


New York, NY 10005

Attention: Trust and Securities Services


Re: [    ]%
Series [A][B] Notes due [            ]


Reference
is hereby made to the Indenture, dated as of July 24, 2006, as amended by the First
Supplemental Indenture, dated as of October 13, 2006 (as so amended and
supplemented, the “Indenture”),
between Baltimore Gas and Electric Company, a Maryland corporation, as issuer
(the “Company”), and Deutsche Bank Trust
Company Americas, as trustee. 
Capitalized terms used but not defined herein shall have the meanings
given to them in the Indenture.


                       ,
(the “Owner”) owns and proposes to exchange
the Note[s] or interest in such Note[s] specified herein, in the principal
amount of $                       
in such Note[s] or interests (the “Exchange”).  In connection with the Exchange, the Owner
hereby certifies that:


1.                                      Exchange of Restricted
Definitive Notes or Beneficial Interests in a Restricted Global Note for
Unrestricted Definitive Notes or Beneficial Interests in an Unrestricted Global
Note.


(a)           o  Check if Exchange is from beneficial interest in a Restricted Global
Note to beneficial interest in an Unrestricted Global Note.  In connection with the Exchange of the Owner’s
beneficial interest in a Restricted Global Note for a beneficial interest in an
Unrestricted Global Note in an equal principal amount, the Owner hereby
certifies (i) the beneficial interest is being acquired for the Owner’s own
account without transfer, (ii) such Exchange has been effected in compliance
with the transfer restrictions applicable to the Global Notes and pursuant to
and in accordance with the United States Securities Act of 1933, as amended
(the “Securities Act”), (iii) the restrictions
on transfer contained in the Indenture and the Private Placement Legend are not
required in order to maintain compliance with the Securities Act and (iv) the
beneficial interest in an Unrestricted Global Note is being acquired in
compliance with any applicable blue sky securities laws of any state of the
United States.


(b)           o 
Check if Exchange is from beneficial interest in a Restricted Global
Note to Unrestricted Definitive Note.  In connection
with the Exchange of the Owner’s beneficial interest in a Restricted Global
Note for an Unrestricted Definitive Note, the Owner hereby certifies (i) the
Definitive Note is being acquired for the Owner’s own account without transfer,
(ii) such Exchange has been effected in compliance with the transfer
restrictions applicable to the Restricted Global Notes and pursuant to and in
accordance with the Securities Act, (iii) the restrictions on transfer
contained in the Indenture and the Private Placement Legend are not required in
order to maintain compliance with



 D-1
 






 



the Securities Act and (iv) the Definitive Note is
being acquired in compliance with any applicable blue sky securities laws of
any state of the United States.


(c)           o 
Check if Exchange is from Restricted Definitive Note to beneficial
interest in an Unrestricted Global Note.  In connection
with the Owner’s Exchange of a Restricted Definitive Note for a beneficial
interest in an Unrestricted Global Note, the Owner hereby certifies (i) the
beneficial interest is being acquired for the Owner’s own account without
transfer, (ii) such Exchange has been effected in compliance with the transfer
restrictions applicable to Restricted Definitive Notes and pursuant to and in
accordance with the Securities Act, (iii) the restrictions on transfer
contained in the Indenture and the Private Placement Legend are not required in
order to maintain compliance with the Securities Act and (iv) the beneficial
interest is being acquired in compliance with any applicable blue sky
securities laws of any state of the United States.


(d)           o 
Check if Exchange is from Restricted Definitive Note to Unrestricted
Definitive Note.  In connection with the Owner’s Exchange of a
Restricted Definitive Note for an Unrestricted Definitive Note, the Owner
hereby certifies (i) the Unrestricted Definitive Note is being acquired for the
Owner’s own account without transfer, (ii) such Exchange has been effected in
compliance with the transfer restrictions applicable to Restricted Definitive Notes
and pursuant to and in accordance with the Securities Act, (iii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities Act
and (iv) the Unrestricted Definitive Note is being acquired in compliance with
any applicable blue sky securities laws of any state of the United States.


2.                                      Exchange of Restricted
Definitive Notes or Beneficial Interests in Restricted Global Notes for
Restricted Definitive Notes or Beneficial Interests in Restricted Global Notes.


(a)           o  Check if Exchange is from beneficial interest in a Restricted Global
Note to Restricted Definitive Note. 
In connection with the Exchange of the Owner’s beneficial interest in a
Restricted Global Note for a Restricted Definitive Note with an equal principal
amount, the Owner hereby certifies that the Restricted Definitive Note is being
acquired for the Owner’s own account without transfer.  Upon consummation of the proposed Exchange in
accordance with the terms of the Indenture, the Restricted Definitive Note
issued will continue to be subject to the restrictions on transfer enumerated
in the Private Placement Legend printed on the Restricted Definitive Note and
in the Indenture and the Securities Act.


(b)           o 
Check if Exchange is from Restricted Definitive Note to beneficial
interest in a Restricted Global Note.  In connection
with the Exchange of the Owner’s Restricted Definitive Note for a beneficial
interest in the Restricted Global Note, the Owner hereby certifies (1) the
beneficial interest is being acquired for the Owner’s own account without
transfer and (ii) such Exchange has been effected in compliance with the
transfer restrictions applicable to the Restricted Global Notes and pursuant to
and in accordance with the Securities Act, and in compliance with any
applicable blue sky securities laws of any state of the United States.  Upon consummation of the proposed Exchange in
accordance with the terms of the Indenture, the beneficial interest issued will
be subject to the restrictions on transfer enumerated in the Private Placement
Legend printed on the relevant Restricted Global Note and in the Indenture and
the Securities Act.



 D-2
 






 



This
certificate and the statements contained herein are made for your benefit and
the benefit of the Company.


	
   

  	
   

  	
   

  
	
  

  	
  [Insert Name of Owner]

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
  Dated:

  	
   

  	
  ,

  	
   

  	
   

  	
   

  
								



 



 D-3