Exhibit 10(a)






                       FULL REQUIREMENTS SERVICE AGREEMENT

                                     BETWEEN

                        CONSTELLATION POWER SOURCE, INC.

                                       AND

                       BALTIMORE GAS AND ELECTRIC COMPANY


                               DATED JUNE 14, 2000











*** The  asterisks  on pages 5, 13, 23 and  Exhibit B denote  that  confidential
portions  of this  exhibit  have been  omitted in reliance on Rule 24 b-2 of the
Securities  Exchange Act of 1934. The confidential  portions have been submitted
separately to the Securities and Exchange Commission.







                                TABLE OF CONTENTS





                                                                                             Page
                                                                                            

ARTICLE 1.                 Definitions                                                         2

ARTICLE 2.                 Conditions Precedent; Effective Date; Term                          6

ARTICLE 3.                 Supplier Responsibilities; Full Requirements Service                7

ARTICLE 4.                 Delivery Point; Transmission Service                                9

ARTICLE 5.                 BGE Responsibilities                                               10

ARTICLE 6.                 Billing and Payment                                                11

ARTICLE 7.                 Price                                                              13

ARTICLE 8.                 Events of Default; Remedies                                        14

ARTICLE 9.                 Credit Support                                                     17

ARTICLE 10.                Indemnification                                                    19

ARTICLE 11.                Limitation of Liability                                            19

ARTICLE 12.                Force Majeure                                                      20

ARTICLE 13.                Representations and Warranties                                     21

ARTICLE 14.                Miscellaneous                                                      21

APPENDIX A                 SAMPLE PJM BILL
APPENDIX B                 PRICE FREEZE SERVICE PRICES
APPENDIX C                 LITIGATION DISCLOSURE



                                        i



                       FULL REQUIREMENTS SERVICE AGREEMENT


         THIS  FULL  REQUIREMENTS  SERVICE  AGREEMENT  ("Agreement"),  made  and
 entered  into as of this 14th day of June,  2000 by and  between  Constellation
 Power Source, Inc., a Delaware corporation  ("Supplier" or "CPS") and Baltimore
 Gas and Electric Company, a Maryland  Corporation  ("BGE") (each individually a
 "Party", or collectively, the "Parties").

                               W I T N E S S E T H

         WHEREAS,  on April 8, 1999,  Maryland  enacted the Electric  Choice and
 Competition  Act authorizing  customer  choice and  competition  among electric
 suppliers;

         WHEREAS,  on November 10, 1999 the Maryland  Public Service  Commission
 issued an order approving the terms of a settlement providing for retail choice
 within BGE's service territory;

         WHEREAS,  the Maryland PSC Order directs BGE to supply electric service
 for a  period  of up to six  years  to  those  retail  customers  within  BGE's
 traditional  retail  service  territory that choose not to purchase their power
 supply from alternative competitive suppliers;

         WHEREAS,  the Maryland PSC Order  provides that, in order to ensure the
 reliability  of supply  for  electric  service  provided  by BGE and to further
 ensure  that  BGE  can  meet  its  obligations,  BGE  may  enter  into  a  full
 requirements  contract  with an  Affiliate  for  energy,  capacity,  losses and
 ancillary  services needed by BGE for such specified retail load until June 30,
 2003;

     WHEREAS,  Supplier is  authorized  to makes sales of energy,  capacity  and
ancillary services at market based rates pursuant to Constellation Power Source,
Inc., 79 FERCP.  61,167 (1997) and its market based rates tariff,  Constellation
Power Source,  Inc. Rate Schedule FERC No. 11, Revision No. 2 in accordance with
FERC Delegated  Letter Order of March 29, 2000 in FERC Docket No.  ER00-1598-000
(the "Supplier Tariff");

     WHEREAS,  this Agreement is entered into pursuant to and in accordance with
the Supplier Tariff; and

     WHEREAS,  Supplier and BGE are entering into this Agreement for the purpose
of establishing  the terms and conditions  under which Supplier will supply such
full requirements service to BGE.

     NOW,  THEREFORE,  in consideration of the premises and the mutual covenants
set forth herein, the Parties hereto agree as follows:

                                        1

                                    ARTICLE 1
                                   DEFINITIONS

     1.1 Definitions. For all purposes of this Agreement, the following terms as
used in this  Agreement  shall have the  following  meanings.  Except  where the
context otherwise requires, definitions and terms expressed in the singular will
include the plural and vice versa.

         "Affiliate"  means,  with  respect to a Person,  any other Person that,
         directly or indirectly through one or more intermediaries, controls, is
         controlled by or is under common  control with such first  Person.  The
         term "control"  means the  possession,  directly or indirectly,  of the
         power to direct or cause the direction of the management or policies of
         a Person,  whether  through  the  ownership  of voting  securities,  by
         contract or otherwise.

         "Aggregate  Retail Load" means the load  obligation  as reported to PJM
         for Price Freeze Service,  Default Service and Special Contract Service
         retail load of BGE during the Delivery Term.

         "Agreement" means this Full Requirements  Service Agreement,  including
         the Appendices, as amended, modified or supplemented from time to time.

         "BGE" means Baltimore Gas and Electric Company, a Maryland  corporation
         and its successors and permitted assigns hereunder.

         "Business  Day" means a day on which  Federal  Reserve  member banks in
         Baltimore Maryland are open for business; and a Business Day shall open
         at 8:00 a.m.  and  close at 5:00 p.m.  Eastern  Standard  (or  Daylight
         Savings) time.

         "CCNPP"  means  Calvert  Cliffs  Nuclear  Power  Plant,  Inc.  and any
         successor thereto.

         "CGI"  means  Constellation  Power  Source  Generation,  Inc.  and any
         successor thereto.

         "Creditworthiness  Criteria"  with respect to a Party or its  guarantor
         means (i) a rating of "Baa3" or better from  Moody's,  "BBB-" or better
         from  S&P or  investment  grade as  determined  by  another  nationally
         recognized rating service reasonably  acceptable to the other Party and
         (ii)  a  Net   Worth  of  at  least   Two   Hundred   Million   Dollars
         ($200,000,000).

         "Default Service" means the retail electric  generation default service
         provided by BGE to its  customers  in Maryland in  accordance  with the
         settlement,  the Maryland PSC Order, and BGE's tariffs on file with the
         Maryland PSC.

         "Delivery  Point"  means  any point on the PJM  Transmission  System as
         elected by Supplier.

                                        2

         "Delivery  Term" means the period  commencing on the Effective Date and
         ending on June 30, 2003, unless this Agreement is earlier terminated in
         accordance with its terms.

         "Effective Date" means 12:01 a.m. on the later of: (a) July 1, 2000; or
         (b) the first day of the month  following the month in which all of the
         conditions  specified in Article 2 are satisfied or waived by the Party
         for whose benefit such condition  exists,  or if such date is less than
         five Business Days prior to the first day of the next succeeding month,
         then  the  first  day  of the  second  month  thereafter,  or as may be
         mutually agreed upon by the Parties.

         "Electricity  Supplier  Coordination  Tariff" means the BGE Electricity
         Supplier  Coordination Tariff approved by the Maryland PSC, as amended,
         modified or supplemented from time to time.

         "FERC" means the Federal Energy Regulatory Commission and any successor
         thereto.

         "Full  Requirements  Service" means  all-requirements  electric service
         (minute by minute, hour by hour, day by day) including, but not limited
         to, the  following  products:  energy,  capacity,  ancillary  services,
         Unaccounted For Energy and associated  losses  necessary to fulfill all
         PJM  obligations as they may change from time to time  associated  with
         providing  all-requirements  electric service to BGE's Aggregate Retail
         Load,  as further  defined or limited  pursuant to Article 3. Such Full
         Requirements  Service shall include  changes in customer demand for any
         reason,  including,  but not limited to, seasonal  factors,  daily load
         fluctuations,  increased or  decreased  usage,  demand side  management
         activities, extremes in weather, and other similar events.

         "Governmental  Authority"  means the government of any federal,  state,
         municipal or other  political  subdivision,  including all agencies and
         instrumentalities of such governments and political subdivisions.

         "Interest Rate" means,  for any date, the lesser of (a) two (2) percent
         over the per annum rate of interest  equal to the prime lending rate as
         may from time to time be  published  in The Wall Street  Journal  under
         "Money Rates" and (b) the maximum rate permitted by applicable law.

         "Load  Serving  Entity  (LSE)"  means  an  entity,   including  a  load
         aggregator or power marketer, that: (i) is serving end-users within the
         PJM Control Area,  and (ii) has been granted the  authority,  or has an
         obligation pursuant to state or local law, regulation or franchise,  to
         sell electric  energy to end-users  within the PJM Control Area, or the
         duly designated agent of such an entity.

         "Maryland  PSC" means the Maryland  Public  Service  Commission and any
         successor thereto.

                                        3

         "Maryland  PSC Order"  means the  November 10, 1999 Order issued by the
         Maryland  PSC  allowing,   among  other   things,   retail  choice  for
         electricity consumers, requiring that BGE provide electricity supply to
         retail  consumers who do not chose an alternate  supplier,  and further
         allowing BGE to enter into a full  requirements  service agreement with
         an Affiliate for Full  Requirements  Service for BGE's Aggregate Retail
         Load.

         "Moody's"  means  Moody's  Investors  Service,  Inc. and any successor
         thereto.

         "Net Worth" means total assets  (exclusive of  intangible  assets) less
         total   liabilities  as  reflected  on  a  balance  sheet  prepared  in
         accordance with generally accepted accounting  principles  consistently
         applied.

         "Operating Committee" means a committee formed by one representative of
         Supplier and one  representative  of BGE for the purposes  described in
         this Agreement and as otherwise directed by the Parties.

         "Person"  means  any  individual,  sole  proprietorship,   corporation,
         partnership,  joint venture,  limited  liability  partnership,  limited
         liability  company,  trust,  unincorporated  association,  institution,
         Governmental Authority or any other entity.

         "PJM"  means  PJM  Interconnection,  L.L.C.,  the  independent  system
         operator for the PJM Control Area organized and operating  pursuant to
         the PJM Operating Agreement and any successor thereto.

         "PJM  Operating  Agreement"  means the Amended and  Restated  Operating
         Agreement of PJM Interconnection,  LLC dated June 2, 1997 and effective
         January 1, 1998,  as  amended,  modified or  supplemented  from time to
         time.

         "PJM OATT" means the PJM Open Access  Transmission  Tariff administered
         by PJM, as amended, modified or supplemented from time to time.

         "PJM Transmission System" has the meaning given in the PJM OATT.

         "Price  Freeze  Service"  means the retail  electric  generation  price
         freeze  service  provided  by BGE  to  its  customers  in  Maryland  in
         accordance  with the  settlement,  the  Maryland  PSC Order,  and BGE's
         tariffs on file with the Maryland PSC.

         "Reliability  Assurance  Agreement"  means  the  Reliability  Assurance
         Agreement  among Load  Serving  Entities in the PJM Control  Area dated
         June 2, 1997, as amended, modified or supplemented from time to time.

         "Required  Regulatory  Approvals"  means FERC  approval  of each of the
         applications  of CGI and CCNPP for  authority  to sell  electricity  at
         market based rates including  associated waivers such that, among other
         things, the agreement between CGI and CPS and the

                                        4


          agreement  between  CCNPP and CPS are not be required to be filed with
          FERC until 30 days after service commences under each agreement;  FERC
          approval  of the  application  of CPS to modify its market  based rate
          tariff  to  remove  any   restriction   preventing   it  from  selling
          electricity to BGE thereunder or otherwise  requiring CPS to file this
          Agreement  between  it and  BGE  with  FERC  in a  manner  other  than
          inclusion in CPS's quarterly report;  FERC approval of the application
          of  BGE  to  modify  its  market  based  rate  tariff  to  remove  any
          restriction  preventing it from selling  electricity to CPS thereunder
          or  otherwise  requiring  the  filing of  agreements  for the sales of
          electricity  among  BGE and its  affiliates  with  FERC  prior  to the
          commencement  of  such  sales;   Maryland  PSC  approval  of  the  BGE
          settlement  providing for,  among other things,  the  commencement  of
          retail choice within the BGE service territory;  Maryland PSC approval
          of the asset transfer and other transactions taken pursuant to the BGE
          settlement;  Pennsylvania  Public Utility  Commission  approval of the
          asset transfer and other transactions being undertaken pursuant to the
          BGE  settlement;  FERC  approval  of  the  transfer  by  BGE  of  FERC
          jurisdictional  facilities and contracts  associated  therewith;  FERC
          approval of the  Interconnection  Agreements between CCNPP and BGE and
          between CGI and BGE; FERC authorization for the issuance of securities
          and  assumption  of  liabilities;  receipt from the  Internal  Revenue
          Service of a favorable  Private  Letter Ruling with respect to the tax
          free distributions of certain assets from BGE to Constellation  Energy
          Group  and its  affiliates;  and  the  Nuclear  Regulatory  Commission
          approval of the transfer of the Calvert Cliffs Operating Licenses from
          BGE to CCNPP, all without material modification or condition. Further,
          CCNPP  and CGI  shall  have  made  good  faith  filings  with the FERC
          relating to exempt  wholesale  generator status such that each will be
          accorded  such status as of the later of July 1, 2000 or when  service
          commences hereunder.

          "Special  Contract  Service"  means  the  retail  electric  generation
          service provided by BGE to *** and ***.

          "S&P"  means  Standard & Poor's  Ratings  Group,  a division of McGraw
          Hill, Inc. and any successor thereto.

          "Supplier"  means  Constellation   Power  Source,   Inc.,  a  Delaware
          corporation and its successors and permitted assigns hereunder.

          "Taxes" means any or all ad valorem, property, severance,  generation,
          first use, conservation, Btu or energy, transportation, utility, gross
          receipts,   privilege,   sales,  use,   consumption,   excise,  lease,
          transaction,  and other taxes,  governmental charges,  licenses, fees,
          permits and assessments,  or increases therein, other than taxes based
          on net income or net worth.

          "Unaccounted  For Energy" means the difference  between the hourly BGE
          system load and the sum of (i) the  estimated  hourly  customer  loads
          (interval metered and profiled) and (ii) losses.







*** The asterisk  denotes that  confidential  portions of this exhibit have been
omitted in reliance on Rule 24 b-2 of the  Securities  Exchange Act of 1934. The
confidential  portions  have been  submitted  separately to the  Securities  and
Exchange Commission.

                                        5


1.2  Additional  Defined  Terms.  Each of the  following  terms has the  meaning
     specified in the Article, Section or Appendix set forth opposite such term:




     Term                                                               Section/Appendix
                                                                             
     AAA                                                                        14.11
     Affected Party                                                             8.4
     ALM                                                                        5.4
     Bankruptcy Proceeding                                                      8.1
     Claims                                                                     10
     Confidential Information                                                   14.7
     Defaulting Party                                                           8.1
     Early Termination Date                                                     8.4
     Event of Default                                                           8.1
     Force Majeure                                                              12.1(a)
     Initial Supplier Credit Support                                            9.1(a)
     Interdepartmental Customers                                                3.4
     Margin                                                                     8.2(c)
     Non-Defaulting Party                                                       8.2
     Price                                                                      7.1
     Settlement Amount                                                          8.2(b)
     Term                                                                       2.3
     Termination Payment                                                        8.2(c)



                                    ARTICLE 2
                   CONDITIONS PRECEDENT; EFFECTIVE DATE; TERM

     2.1  Conditions on Obligations of BGE and Supplier.

     The   obligations  of  BGE  and  Supplier  under  this  Agreement  and  the
designation  of the Effective  Date for the  commencement  of this Agreement are
subject to the fulfillment and satisfaction of each of the following  conditions
precedent,  any one or more of which may only be waived in writing,  in whole or
in part, by the Party for whose benefit such condition exists.

     (a) All  representations  and  warranties  of each Party  contained in this
Agreement shall be true and correct in all material respects as of the date when
made and at and as of the  Effective  Date as though  such  representations  and
warranties  had been  made or given on such  date  (except  to the  extent  such
representations  and warranties  specifically  pertain to an earlier date),  and
each Party shall have  delivered to the other Party a  certificate,  dated as of
the  Effective  Date and signed by one of its duly  authorized  officers to such
effect.

                                        6


     (b) All Required Regulatory Approvals shall have been received and be final
and in full force and effect  pursuant to a final,  nonappealable  order,  which
approvals shall not have materially modified the express terms and conditions of
this Agreement.

     (c) Each Party shall have delivered to the other Party a certificate  dated
as of the  Effective  Date and  signed by one of such  Party's  duly  authorized
officers specifying that each of the conditions  precedent applicable to it have
been satisfied or waived.

     2.2 Satisfaction of Conditions.

     Each Party agrees to cooperate in good faith with the other Party and shall
take all practicable actions and devote resources reasonably necessary to obtain
satisfaction  of the  conditions  set forth in Section 2.1 as soon as reasonably
possible.  In the event that the  conditions  set forth in  Section  2.1 are not
satisfied or are not waived on or before July 1, 2001, then either Party, at its
option,  may terminate  this  Agreement by delivering a notice of termination to
the other Party.  Notice of  termination  for failure of a condition  must be in
writing and issued prior to the date when the  condition is belatedly  satisfied
or  waived  by the Party for whose  benefit  such  condition  exists,  and shall
identify in reasonable  detail the  condition(s)  which have not been satisfied.
Upon any  termination  of this  Agreement in  accordance  with this Section 2.2,
neither Party shall have any obligation to the other under this Agreement.

     2.3 Term.

     Unless  earlier  terminated in accordance  with Section 2.2 or as otherwise
provided  in  Article 8, this  Agreement  shall  remain in effect  from the date
hereof  through and  including  the end of the Delivery  Term  ("Term").  At the
expiration  of the Term,  the Parties  shall no longer be bound by the terms and
conditions  of this  Agreement,  except to the extent  necessary  to enforce the
rights and  obligations of the Parties arising under this Agreement prior to the
expiration of the Term.


                                    ARTICLE 3
              SUPPLIER RESPONSIBILITIES; FULL REQUIREMENTS SERVICE

     3.1 PJM Member.

     Supplier  shall,  prior to the  Effective  Date,  (i) be a member,  in good
standing,  of PJM and maintain a settlement  account  established  in accordance
with the rules  and  criteria  established  by PJM  throughout  the Term of this
Agreement,  or (ii)  have an  agreement  in  place,  for the  full  Term of this
Agreement,  with a PJM  member  whereby  the PJM member  agrees to  include  the
Aggregate  Retail  Load to be served by  Supplier  under this  Agreement  in its
settlement account.

                                        7


     3.2 Full Requirements Service.

     During the Delivery  Term,  Supplier shall sell and deliver to the Delivery
Point and BGE shall receive and purchase Full Requirements Service sufficient to
serve BGE's Aggregate Retail Load. As a provider of Full  Requirements  Service,
Supplier is solely  responsible for satisfying all  requirements  and paying all
costs  incurred or to be incurred to provide  such  service  including,  without
limitation, all costs or other requirements to furnish capacity, energy, losses,
Unaccounted For Energy and ancillary  services  associated with the provision of
Full Requirements  Service.  Supplier is also solely responsible for meeting any
other requirements and paying any other costs now or hereafter imposed by PJM or
imposed pursuant to the Reliability Assurance Agreement from time to time during
the Delivery  Term which are  attributable  to any component of the provision of
Full Requirements  Service. If PJM allocates any expenses or uplift costs to the
Full Requirements  Service provided by Supplier (on a load or peak load basis or
otherwise),  the expenses or costs so allocated  will be borne by Supplier alone
without recourse to BGE.

     3.3 Losses; Unaccounted For Energy.

     Supplier shall be responsible for the Aggregate  Retail Load as reported to
PJM which includes all transmission, sub-transmission and/or distribution losses
associated  with the delivery of electricity  supplied under this Agreement from
the sources of its supply to the meters of those  retail  customers  taking Full
Requirements  Service.  The hourly  Unaccounted  For Energy  associated with the
electricity  supplied  under this  Agreement  shall be included in the Aggregate
Retail  Load.  For  purposes  of  calculating  amounts  owed by BGE to  Supplier
hereunder  losses and  Unaccounted  For Energy  shall be  included on a pro-rata
basis (or in such other manner as determined by the  Operating  Committee)  over
each  customer  class of Price  Freeze  Service,  Default  Service  and  Special
Contract Service.

     3.4 Interdepartmental Customers; Station Service.

     (a)  Full   Requirements   Service   consumed  by  BGE  or  its  Affiliates
("Interdepartmental  Customers")  shall be included in Aggregate  Retail Load by
rate class as follows. If Interdepartmental  Customers'  consumption is provided
by BGE  pursuant  to a rate  schedule,  then BGE  shall  pay  Supplier  for Full
Requirements Service associated with such customers the Price applicable to such
schedule as set forth in Appendix B. If Interdepartmental Customers' consumption
is not provided by BGE pursuant to a rate schedule,  then BGE shall pay Supplier
for  Full  Requirements   Service  associated  with  such  customers  the  Price
applicable to GL Secondary customers as set forth in Appendix B.

     (b) If at any time  during the Term of this  Agreement,  PJM  modifies  its
practices  such that the  station  service  requirements  of CCNPP or CGI are no
longer netted or otherwise accounted for as interchange for PJM purposes, and as
a  consequence  CCNPP and CGI are required to purchase  retail power for station
service  purposes,  then Supplier shall supply such station service power to BGE
for resale by BGE to CCNPP and CGI, unless BGE is precluded

                                        8


from  providing such power by law or regulation.  BGE shall  reimburse  Supplier
100% of Supplier's actual costs to supply such station service power.

     3.5 Maryland Environmental Disclosure Requirements.

     Subject to any  confidentiality  provisions to which it is bound,  Supplier
will provide to BGE, to the best of its  knowledge,  the sources of  electricity
used to supply Full Requirements Service, fuel mix and environmental  disclosure
information  in a timely  manner  and in an  appropriate  form to enable  BGE to
comply with Maryland PSC or other governmental or regulatory agency requirements
relating to reporting of such information.

     3.6 Renewable Energy Resources.

     During the Term of this  Agreement,  Supplier  agrees to utilize the output
that it receives from the Brighton Dam facility that is owned and/or operated by
Alternative Energy Associates, the Safe Harbor Hydroelectric plant that is owned
and/or  operated by Safe Harbor Water Power  Corporation and the BRESCO facility
that is owned  and/or  operated by  Baltimore  Refuse  Energy  Systems  Company,
Limited  Partnership  to serve the Aggregate  Retail Load  hereunder;  provided,
however,  that if the Operating Committee determines that at any time during the
Term the output available to Supplier from such resources  exceeds the renewable
resource requirements imposed upon BGE by Article 7-615 of the Maryland Electric
Customer  Choice and Competition Act of 1999, as amended from time to time, then
the  Operating  Committee  shall  determine the  appropriate  allocation of such
resources.


                                    ARTICLE 4
                      DELIVERY POINT; TRANSMISSION SERVICE

     4.1 Title; Risk of Loss.

     Title  to and  risk  of  loss  related  to the  Full  Requirements  Service
delivered by Supplier in accordance with this Agreement shall pass to BGE at the
Delivery Point.

     4.2 Fixed Transmission Rights.

     If  the  PJM  Control  Area  experiences   congestion,   Supplier  will  be
responsible  for any  congestion  costs  incurred in  delivering  power from the
Delivery Point to BGE's load busses supplying  Aggregate Retail Load. During the
Delivery Term, BGE shall,  at no cost to Supplier,  assign,  transfer or pay, as
applicable, to Supplier any and all transmission service rights, revenues and/or
fixed  transmission  rights (FTR's)  associated  with system  congestion that it
receives or to which it is entitled. It is the intent of the Parties that to the
extent Supplier is responsible for any congestion  related costs associated with
the delivery of Full  Requirements  Service  hereunder,  that any  corresponding
payments or benefits  received by BGE associated  with or related to payments in
respect of congestion be paid or transferred by BGE to Supplier.

                                        9



     4.3 Network Transmission and Distribution Service.

     BGE shall be responsible,  at its sole cost and expense,  for the provision
of  Network  Transmission  Service  pursuant  to the PJM OATT  and  distribution
service at and from the Delivery Point.


                                    ARTICLE 5
                              BGE RESPONSIBILITIES

     5.1 Load Information.

     BGE shall  provide  Supplier  with  timely and best  available  information
regarding  the  Aggregate  Retail  Load to be served  under  this  Agreement  as
reasonably  requested  by  Supplier  from  time to time  during  the  Term.  The
information  provided  to  Supplier  by  BGE  shall  be in a  format  reasonably
acceptable to Supplier and shall permit Supplier to properly forecast,  schedule
and bill or verify billings of BGE for Full Requirements  Service.  In addition,
BGE shall provide timely notice to Supplier of any changes,  either additions or
deletions  (including  loss of or  addition  of  customers  and any  anticipated
changes in customer usage or usage patterns), to the retail load being served by
BGE. In the event that  Supplier  requests data in a format that requires BGE to
dedicate incremental resources in excess of 40 manhours to accomplish,  BGE will
provide Supplier an estimate of its actual costs to provide such data format and
will be under no  obligation  to incur such costs unless and until  Supplier has
agreed to reimburse BGE the amount of such actual costs.

     5.2   Authorization   for  Supplier  to  Assume   Certain  LSE  Rights  and
Obligations.


     BGE shall provide Supplier all  authorizations  or other  demonstrations of
authority required for Supplier to gain access to and assume  responsibility for
administration  of BGE's PJM  account and  otherwise  to  facilitate  Supplier's
assumption of certain of BGE's rights and  obligations  as a Load Serving Entity
as  required  pursuant  to the terms of this  Agreement.  BGE hereby  makes such
authorizations  to Supplier  for the Term of this  Agreement  for the purpose of
scheduling,   electing,   exercising  and/or   implementing   BGE's  rights  and
obligations  under the PJM  Operating  Agreement and the  Reliability  Assurance
Agreement as may be required to fulfill Supplier's  obligations pursuant to this
Agreement or as otherwise necessary in connection with this Agreement.

     5.3 Reporting to PJM and Supplier.

     BGE shall report to PJM and to Supplier all load  obligations  attributable
to  Supplier,  including  hourly  Aggregate  Retail Load  (including  losses and
Supplier's share of Unaccounted For Energy),  Aggregate  Transmission  Peak Load
Contribution, and Aggregate Capacity Peak Load Contribution.  Reporting shall be
in accordance  with PJM reporting  requirements  to support PJM  accounting  and
billing  procedures for both estimated and actual amounts.  In calculating  such
obligations, together with reconciliations of actual to estimated load data, BGE
shall follow

                                       10

the procedures set forth in the Electricity Supplier Coordination Tariff and PJM
OATT. All data provided to Supplier in accordance with this Section 5.3 shall be
allocated among the relevant  customer  classes,  as set forth in Appendix B, to
accommodate  appropriate  billing  pursuant  to Section  6.1.  For  purposes  of
invoicing and payment,  the total Aggregate Retail Load, as reported to PJM on a
wholesale  basis for each  calendar  month  shall  equal  the Full  Requirements
Service delivered by Supplier to BGE hereunder in such calendar month.

     5.4 Active Load Management.

     During the  Delivery  Term,  BGE will  operate its Active  Load  Management
("ALM")  programs  as directed  by the  Operating  Committee  and  otherwise  in
accordance with the provisions of the Electricity  Supplier  Coordination Tariff
and the applicable  Riders to BGE's Retail Electric Service Tariff,  as approved
by the Maryland PSC from time to time.  BGE shall  provide  periodic  reports to
Supplier regarding the amount of ALM available for ALM credits to be used in the
determination  of  capacity   obligation  in  accordance  with  the  Reliability
Assurance  Agreement.  In addition,  BGE shall be responsible for payment of any
ALM credits to retail  customers  and for any  penalties  assessed in accordance
with the  Reliability  Assurance  Agreement  for  failure to  implement  its ALM
programs when so requested by PJM.


                                    ARTICLE 6
                               BILLING AND PAYMENT

     6.1 Billing.

     (a) On or before the fifth  (5th)  Business  Day of each  month,  BGE shall
deliver to Supplier a statement that sets forth: (i) the allocation of Aggregate
Retail  Load  volumes  for  the  preceding  month  among  Price  Freeze  Service
customers, (further allocated to each customer rate classes for which a separate
Price is specified on Appendix B), Default Service customers and each individual
Special Contract customer; (ii) the calculation of the amount due and payable by
BGE for Price Freeze Service,  based upon the volumes allocated to each customer
rate class and the Prices  applicable  thereto as set forth on  Appendix  B; and
(iii) all other information reasonably requested by Supplier to facilitate CPS's
verification of the foregoing values,  including,  without  limitation,  volumes
attributable to Interdepartmental Customers or station service supplied pursuant
to Section 3.4(b).  Such statement  shall  constitute an "invoice" or "bill" for
purposes of amounts due and payable for Full  Requirements  Service allocated to
Price Freeze Service customers.

     (b) On or before the tenth  (10th)  Business  Day of each  month,  Supplier
shall  deliver to BGE an invoice  for the volumes of Full  Requirements  Service
allocated to Default  Service and Special  Contract  Service  customers  for the
preceding  month,  using the volume  data  provided  by BGE  pursuant to Section
6.1(a) and the Prices  applicable  thereto as set forth in Section  7.1.  To the
extent that Supplier's  actual cost for any component of such Full  Requirements
Service  is not  finally  determined  at the  time of such  invoice,  Supplier's
invoice shall include an estimate for such cost,  subject to  reconciliation  in
subsequent months' invoices pursuant to Section 6.1(c) or

                                       11


Supplier shall bill such costs in arrears.  All invoices rendered by Supplier to
BGE shall also set forth all other  information  reasonably  requested by BGE to
facilitate BGE's verification of Supplier's invoice.

     (c) Because the  allocation of volumes  under Section  6.1(a) are estimated
and  certain  of  Supplier's  costs  under  Section  6.1(b)  may  be  estimated,
quantities  and costs  used in  calculations  under  this  Section  6.1 shall be
subject to  adjustment,  whether  positive or negative,  in  subsequent  months'
calculations,  to reflect  reconciliation  with  actual  values.  Any  resulting
billing  adjustment  (debit or credit) will be reflected in  subsequent  months'
invoices pursuant to Section 6.4.

     6.2 Payment.

     All invoices  pursuant to Section  6.1(a) and (b) shall be due and payable,
unless otherwise agreed by the Parties, on the first Business Day after the 19th
calendar  day of the month in which the invoice is rendered.  Invoices  shall be
sent via  facsimile  or other  means  agreed  to by the  Parties.  BGE will make
payments by wire transfer,  or by other  mutually  agreeable  method(s),  to the
account of Supplier as designated by Supplier.  Any amounts,  both principal and
interest, remaining unpaid after the due date will be deemed delinquent and will
accrue  interest at the Interest Rate,  such interest to be calculated  from the
due date to the date the unpaid amount is paid in full.

     6.3 Disputed Bills.

     If either Party,  in good faith,  disputes an invoice,  the disputing Party
shall  immediately  notify the other Party of the basis for the dispute  and, in
the case of a dispute by BGE, pay the portion of such  statement  conceded to be
correct no later than the due date.  Each Party  shall have the right to dispute
any invoice prior to the lapse of 12 months from the rendition  thereof.  If any
disputed amount is ultimately determined to be due to Supplier, it shall be paid
within two (2) days of such  determination  along with  interest  accrued at the
Interest  Rate until the date  paid.  Inadvertent  overpayments  by BGE shall be
returned by Supplier  upon  request or  deducted  by  Supplier  from  subsequent
payments,  with  interest  accrued at the  Interest  Rate until the date paid or
deducted.

     6.4 Billing Adjustments.

     (a) The invoices rendered  hereunder may be adjusted by the Party rendering
such  invoice  for  any  errors  in  arithmetic,  computation,  meter  readings,
estimating,  or  otherwise  no later than twelve (12) months  after the date the
bill was rendered.  Any billing  adjustment  shall be in writing and shall state
the specific basis for the adjustment.  A billing  adjustment shall constitute a
new bill for the purposes of this Section 6.4. An adjusted bill shall be binding
on the Party that  renders it twelve  (12)  months  after the bill is  rendered.
Adjustments to reconcile estimated quantities or costs to actuals shall carry no
interest; provided, however, that if at any time Supplier is not an Affiliate of
BGE, then adjustments shall carry interest at the Interest Rate.

                                       12


     (b) Subject to Section 6.4(a), overpayments or underpayments resulting from
a billing adjustment or billing challenge shall bear interest  calculated at the
Interest  Rate. In the case of an  underpayment,  interest shall accrue from the
due date of the bill to which the  adjustment  or challenge  relates to the date
the  additional  charge is paid. In the case of an  overpayment,  interest shall
accrue from the date the amount  being  refunded was received by Supplier to the
date the refund is made.

     6.5 PJM Billing.

     BGE shall request PJM to invoice Supplier  directly for charges and credits
relating to Supplier's  obligation to deliver Full  Requirements  Service to BGE
under this  Agreement.  BGE shall also request PJM to invoice BGE separately for
charges and credits (other than credits for the account of Supplier as described
in  Section  4.2)  relating  to  BGE's  rights  and  obligations  as  a  network
transmission  customer  and a  Transmission  Owner and  otherwise as the Parties
agree.  Appendix A attached hereto and made a part hereof  allocates the charges
and credits  currently  included on a PJM consolidated bill between Supplier and
BGE based upon the Parties' expectation of the allocation of charges and credits
after the Effective Date of this Agreement.


                                    ARTICLE 7
                                      PRICE

     7.1 Price.

     (a)  The  "Price"  payable  by BGE to  Supplier  for the  delivery  of Full
Requirements Service hereunder shall be determined as follows:

     (i) for each megawatt-hour of Full Requirements Service ***;

     (ii) for the total  quantity  of Full  Requirements  Service  delivered  to
Default Service  customers and Special Contract Service  customers,  the "Price"
***; and

     (iii) for the total  quantity  of station  service  delivered  pursuant  to
Section 3.4(b), the "Price" is ***.







*** The asterisk  denotes that  confidential  portions of this exhibit have been
omitted in reliance on Rule 24 b-2 of the  Securities  Exchange Act of 1934. The
confidential  portions  have been  submitted  separately to the  Securities  and
Exchange Commission.

                                       13


     7.2 Taxes.

     (a) Supplier shall pay all Taxes levied in respect of the Full Requirements
Service,  its sale, and the handling  thereof prior to the Delivery  Point.  BGE
shall pay all such Taxes levied on such Full Requirements  Service at, and from,
the Delivery Point.

     (b) For any new Taxes levied with respect to the Full Requirements  Service
after the Effective  Date and to the extent  permitted by the settlement and the
Maryland PSC Order, BGE will fully support and pursue in good faith the recovery
of any such new Tax levied on  Supplier  from BGE's  Full  Requirements  Service
customers.  To the extent  such new Taxes are  recoverable  by BGE from its Full
Requirements Service customers, BGE shall reimburse Supplier for such Taxes paid
by Supplier.

     7.3 Sales for Resale.

     All Full Requirements  Service delivered by Supplier to BGE hereunder shall
be sales for resale,  with BGE  reselling  such Full  Requirements  Service.  At
Supplier's  request,  BGE shall  obtain  and  provide  Supplier  with any resale
certificates to evidence that the deliveries hereunder are sales for resale.

     7.4 Payment Netting.

     Payments  owing by each Party on any day under this  Agreement or any other
agreement  between the Parties shall be offset so that only the net amount shall
be paid by the Party having the greater payment obligation on such day.


                                    ARTICLE 8
                           EVENTS OF DEFAULT; REMEDIES

     8.1 Events of Default.  An "Event of Default" shall mean, with respect to a
Party ("Defaulting Party"), the occurrence of any of the following:

     (i) the failure to make,  when due, any payment  required  pursuant to this
Agreement if such failure is not remedied  within three (3) Business  Days after
written  notice of such  failure is given by the other  Party and  provided  the
payment is not the subject of a good faith dispute as described in Article 6;

     (ii) any  representation  or warranty made by the  Defaulting  Party herein
prove to be false or misleading in any material respect;

     (iii) the  failure  of the  Defaulting  Party,  in a material  respect,  to
perform or comply with any covenant set forth in this Agreement and such failure
is not excused by Force  Majeure or cured within  three (3) Business  Days after
receipt of written notice thereof from the other Party;

                                       14

     (iv) the failure of the  Defaulting  Party to maintain  any of the security
requirements  set forth in Article 9, and such failure is not cured or rectified
within ten (10) days after notice from the other Party; and

     (v) the  Defaulting  Party  shall be  subject  to a  Bankruptcy  Proceeding
("Bankruptcy  Proceeding"  means with respect to a Party, such Party (a) files a
petition or otherwise  commences a proceeding under any bankruptcy,  insolvency,
reorganization  or similar  law,  or has any such  petition  filed or  commenced
against it, (b) makes an assignment or any general  arrangement  for the benefit
of creditors,  (c) otherwise becomes bankrupt or insolvent (however  evidenced),
(d) has a liquidator,  administrator,  receiver, trustee, conservator or similar
official appointed with respect to it or any substantial portion of its property
or assets, or (e) is unable to pay its debts as they fall due).

     8.2. Remedies upon an Event of Default.

     (a)  After  the  occurrence  of an  Event  of  Default  with  respect  to a
Defaulting  Party, the other Party (the  "Non-Defaulting  Party") shall have the
right,  without prior notice,  to liquidate and terminate  this Agreement at any
time and from time to time,  with the minimum period of notice required by FERC,
if applicable,  and shall  calculate,  in a commercially  reasonable  manner,  a
Settlement  Amount for this  Agreement as of the time of its  termination  or as
soon  thereafter  as is  reasonably  practicable  and shall net such  Settlement
Amounts in the manner provided for in Section 8.2(c).

     (b) "Settlement  Amount" shall mean, with respect to this Agreement and the
Non-Defaulting  Party,  the  losses  and costs  (or  gains),  expressed  in U.S.
Dollars, which such party incurs as a result of the liquidation,  including, but
not  limited  to,  losses  and  costs (or  gains)  based  upon the then  current
replacement value of this Agreement together with, at the Non-Defaulting Party's
option, but without duplication, all losses and costs which such party incurs as
a result of maintaining,  terminating, obtaining or re-establishing any hedge or
related  trading  positions.  The Settlement  Amount shall be due to or from the
Non-Defaulting  Party as appropriate.  In calculating a Settlement  Amount,  the
Non-Defaulting  Party  shall  discount  to  present  value  (in  a  commercially
reasonable  manner  based on the Prime Rate as of the date of  termination)  any
amount  which  would  otherwise  have  been due at a later  date and  shall  add
interest  at the  Prime  Rate  to any  amount  due  prior  to  the  date  of the
calculation.  "Prime  Rate" shall mean the prime rate of  interest as  published
from time to time under "Money Rates" by The Wall Street Journal.

     (c) If the  Settlement  Amount  (i) is due the  Non-Defaulting  Party,  the
Non-Defaulting Party shall set off against the Settlement Amount any Margin then
available  to the  Non-Defaulting  Party,  plus (at the  Non-Defaulting  Party's
election)  any or all other  amounts  due to the  Defaulting  Party  under  this
Agreement;  or (ii) is due the Defaulting Party, the Non-Defaulting  Party shall
set  off  against  the  Settlement  Amount  any  Margin  then  available  to the
Defaulting Party, plus (at the Non-Defaulting Party's election) any or all other
amounts due to the Non-Defaulting  Party under this Agreement,  so that all such
amounts  shall  be  netted  to a  single  liquidated  amount  (the  "Termination
Payment")  payable  by one  party  to  the  other.  "Margin"  shall  mean  cash,
securities or

                                       15

other property held by or due from one Party to guarantee or secure  obligations
of the other party under the Agreement.

     (d) Notice that a  liquidation  pursuant to this  Article 8.2 has  occurred
shall be given by the  Non-Defaulting  Party to the Defaulting  Party before the
close of business on the Business Day following such liquidation,  provided that
failure to give such notice shall not affect the validity or  enforceability  of
the  liquidation or give rise to any claim by the  Defaulting  Party against the
Non-Defaulting  Party.  The notice shall  specify the amount of the  Termination
Payment and whether it is owed by or to the Defaulting  Party.  The notice shall
include a written  statement  explaining in reasonable detail the calculation of
such amount. The Termination  Payment shall be made by the Party that owes it on
the second Business Day after such notice is given.

     (e) If the Defaulting Party disputes the Non-Defaulting Party's calculation
of the  Termination  Payment,  in whole or in part, the Defaulting  Party shall,
within two (2) Business Days of receipt of Non-Defaulting Party's calculation of
the Termination Payment,  provide to the Non-Defaulting Party a detailed written
explanation of the basis for such dispute and, if the Termination Payment is due
from the Defaulting Party, shall promptly pay to the  Non-Defaulting  Party such
portion thereof as is conceded to be correct. If the Parties cannot resolve such
dispute within three (3) Business Days of the Non-Defaulting  Party's receipt of
the Defaulting Party's written explanation, then the Defaulting Party may submit
such dispute to arbitration in accordance  with the  arbitration  procedures set
forth in  Section  14.11  hereof;  provided,  however,  that if the  Termination
Payment is due from the  Defaulting  Party,  the  Defaulting  Party  shall first
transfer  collateral (of a type and in a form  acceptable to the  Non-Defaulting
Party) to the Non-Defaulting Party in an amount equal to the disputed and unpaid
portion of the Termination  Payment.  Any payment that is due as a result of the
arbitrator's  award  shall be paid by the  Party  that  owes it  within  two (2)
Business Days after the award is rendered.

     8.3 Setoffs.

     (a) Without limiting its rights under this Article 8 or otherwise, after an
Event of Default,  the Non-Defaulting Party may from time to time set off any or
all amounts which the  Defaulting  Party owes to it (whether under the Agreement
or otherwise  and whether or not then due)  against any or all amounts  which it
owes to the  Defaulting  Party  (whether  under the  Agreement or otherwise  and
whether  or not then  due),  provided  that  any  amount  not then due  which is
included  in such setoff  shall be  discounted  to present  value (in the manner
specified  in Section  8.2(b)) as at the time of setoff (to take  account of the
period  between the date of setoff and the date on which such amount  would have
otherwise been due).

         (b)  Notwithstanding  any other provision of this Agreement,  after the
occurrence of an Event of Default,  or an event which, with the giving of notice
or the  passage of time or both,  would  constitute  an Event of  Default,  with
respect to a Party, the other Party shall have the right to suspend  performance
under this Agreement.

                                       16

     8.4 Other Terminating Events.

     (a) If  performance  by  either  Party (an  "Affected  Party")  under  this
Agreement  becomes subject to regulation of any kind  whatsoever  under any law,
rule, regulation,  order or the like, including any change by the FERC regarding
a Party's authority to sell wholesale power at market-based  rates, to a greater
or different extent than that existing on the Effective Date and such regulation
renders this Agreement illegal or unenforceable then such Party (or either Party
if both Parties are Affected Parties) may terminate and liquidate this Agreement
("Early  Termination  Date") in the manner  contemplated  by Section  8.3 above,
which notice shall specify the basis for declaring such Early Termination Date.

     (b) If an Early Termination Date is declared under circumstances  described
in Section 8.4 (a) above,  both Parties shall calculate their respective  gains,
losses or costs in respect of this  Agreement  as provided in Section  8.2,  and
endeavor in good faith to agree upon the  Termination  Payment payable by either
Party,  and notify the other Party of the  Termination  Payment,  as provided in
Section 8.2.

     8.5 Duty to Mitigate.

     Each Party agrees that it has a duty to mitigate damages and covenants that
it will use commercially reasonable efforts to minimize any damages it may incur
as a result of the other Party's failure to perform pursuant to this Agreement.


                                    ARTICLE 9
                                 CREDIT SUPPORT

     9.1 Supplier Credit Support.

     (a)  On or  before  the  Effective  Date,  unless  Supplier  satisfies  the
Creditworthiness  Criteria at such time, as security for Supplier's  obligations
hereunder,  Supplier  shall  deliver to BGE a guaranty  of payment  from  either
Constellation  Energy  Group,  Inc.,  or  another  Affiliate  of  Supplier  that
satisfies the  Creditworthiness  Criteria,  in an amount equal to the reasonably
determined  credit  exposure of BGE to Supplier taking into account such factors
as market risk, settlement risk, the underlying creditworthiness of Supplier, or
such   other   considerations   as  are   commercially   reasonable   under  the
circumstances. Such credit support shall be available to be drawn upon by BGE in
the event of a default by Supplier of its obligations hereunder, and, subject to
Sections  9.1(b) and (c),  shall be maintained  in effect (by annual  renewal or
otherwise) by Supplier for the Term of this Agreement.

     (b) Supplier may, at any time during the Term of this  Agreement and at its
election,  deliver  substitute  credit  support  to BGE in any of the  following
forms:  (i) a direct pay  irrevocable  letter of credit  directed  to BGE from a
commercial bank with long-term debt ratings of "Baa2" or better from Moody's and
"BBB" or better from S&P; (ii) a performance bond issued by a surety

                                       17


company with a rating of "B+" or better from A.M.  Best  Company;  or (iii) such
other credit support that is acceptable to BGE.

     (c) If at any time during the Term of this Agreement Supplier satisfies the
Creditworthiness Criteria, its obligation to deliver any credit support pursuant
to this  Section 9.1 shall be  suspended  for so long as Supplier  continues  to
satisfy the Creditworthiness Criteria. From and after the date on which Supplier
satisfies the  Creditworthiness  Criteria,  Supplier shall certify to BGE within
thirty (30) days after the end of every calendar quarter that Supplier satisfies
the Creditworthiness Criteria (which certification shall include evidence as BGE
shall  reasonably  request  from time to  time),  and  shall  deliver  financial
statements  to BGE  certified  by a firm  of  certified  public  accountants  of
national  standing  at least  annually  within  one  hundred  twenty  (120) days
following the end of Supplier's fiscal year. If at any time thereafter  Supplier
no longer satisfies the Creditworthiness  Criteria,  then Supplier shall, within
ten (10) Business Days after receipt of a written  notice with respect  thereto,
deliver a guaranty that  satisfies the  requirements  of Section 9.1(a) or other
credit support in accordance with Section 9.1(b).

     9.2 BGE Credit Support.

     (a)  Commencing  with the Effective  Date and  thereafter  during the Term,
within  thirty  (30) days  after the end of every  calendar  quarter,  BGE shall
certify to Supplier  that it  satisfies  the  Creditworthiness  Criteria  (which
certification  shall include evidence as Supplier shall reasonably  request from
time to time), and shall deliver financial statements to Supplier certified by a
firm of certified  public  accountants  of national  standing at least  annually
within one hundred twenty (120) days following the end of BGE's fiscal year. BGE
may satisfy its  obligation  under this  paragraph  by  delivering a copy of its
parent  company's  Annual Report or Form 10K. If at any time during the Term BGE
no longer satisfies the  Creditworthiness  Criteria,  then BGE shall, within ten
(10)  Business  Days after  receipt of a written  notice with  respect  thereto,
deliver to Supplier,  in an amount  equal to the  reasonably  determined  credit
exposure of Supplier to BGE taking into  account  such  factors as market  risk,
settlement  risk,  the  underlying   creditworthiness  of  BGE,  or  such  other
considerations as are commercially  reasonable under the circumstances,  either:
(i) a guaranty of payment from an Affiliate that satisfies the  Creditworthiness
Criteria;  (ii) a letter of credit  directed to Supplier from a commercial  bank
with long-term debt ratings of "Baa2" or better from Moody's and "BBB" or better
from S&P;  (iii) a performance  bond issued by a surety company with a rating of
"B+" or better from A.M. Best Company; or (iv) such other credit support that is
acceptable to Supplier.

     (b) If at any time after  delivering  credit  support  pursuant  to Section
9.2(a),  BGE satisfies the  Creditworthiness  Criteria,  then its  obligation to
deliver any credit  support  pursuant to this Section 9.2 shall be suspended for
so long as BGE continues to satisfy the Creditworthiness  Criteria,  as provided
in Section 9.2(a).

     9.3 Modification or Waiver.

     The  Parties  may agree in  writing  to modify or waive the  provisions  of
Article 9.

                                       18



                                   ARTICLE 10
                                 INDEMNIFICATION

     Each Party  shall  indemnify,  defend  and hold  harmless  the other  Party
(including the other Party's  Affiliates,  trustees,  directors,  board members,
officers,  employees,  and agents)  from any Claims  arising  from or out of any
event,  circumstance,  act or incident  occurring during the period when control
and title to Power is vested, as between the Parties as provided in Article 8.1,
in the indemnifying Party.  "Claims" means all claims or actions,  threatened or
filed and, whether groundless,  false or fraudulent, that directly or indirectly
relate to the subject matter of an indemnity, and the resulting losses, damages,
expenses,  attorneys'  fees and court costs,  whether  incurred by settlement or
otherwise,  and whether such claims or actions are  threatened or filed prior to
or after the termination of this Agreement.


                                   ARTICLE 11
                             LIMITATION OF LIABILITY

     THE PARTIES  CONFIRM  THAT THE  EXPRESS  REMEDIES  AND  MEASURES OF DAMAGES
PROVIDED IN THIS AGREEMENT SATISFY THE ESSENTIAL  PURPOSES HEREOF. FOR BREACH OF
ANY  PROVISION  FOR WHICH AN EXPRESS  REMEDY OR MEASURE OF DAMAGES IS  PROVIDED,
SUCH  EXPRESS  REMEDY OR  MEASURE  OF  DAMAGES  SHALL BE THE SOLE AND  EXCLUSIVE
REMEDY, THE OBLIGOR'S  LIABILITY SHALL BE LIMITED AS SET FORTH IN SUCH PROVISION
AND ALL OTHER  REMEDIES OR DAMAGES AT LAW OR IN EQUITY ARE WAIVED.  IF NO REMEDY
OR MEASURE OF DAMAGES IS EXPRESSLY  HEREIN  PROVIDED,  THE  OBLIGOR'S  LIABILITY
SHALL BE LIMITED TO DIRECT ACTUAL DAMAGES ONLY. SUCH DIRECT ACTUAL DAMAGES SHALL
BE THE SOLE AND EXCLUSIVE  REMEDY AND ALL OTHER REMEDIES OR DAMAGES AT LAW OR IN
EQUITY ARE WAIVED.  UNLESS  EXPRESSLY  HEREIN  PROVIDED,  NEITHER PARTY SHALL BE
LIABLE  FOR ANY  CONSEQUENTIAL,  INCIDENTAL,  PUNITIVE,  EXEMPLARY  OR  INDIRECT
DAMAGES,  LOST PROFITS OR OTHER BUSINESS  INTERRUPTION  DAMAGES,  BY STATUTE, IN
TORT OR CONTRACT,  UNDER ANY INDEMNITY PROVISION OR OTHERWISE.  IT IS THE INTENT
OF THE PARTIES THAT THE  LIMITATIONS  HEREIN IMPOSED ON REMEDIES AND THE MEASURE
OF DAMAGES BE WITHOUT REGARD TO THE CAUSE OR CAUSES RELATED  THERETO,  INCLUDING
THE  NEGLIGENCE  OF ANY  PARTY,  WHETHER  SUCH  NEGLIGENCE  BE  SOLE,  JOINT  OR
CONCURRENT,  OR ACTIVE OR PASSIVE. TO THE EXTENT ANY DAMAGES REQUIRED TO BE PAID
HEREUNDER ARE LIQUIDATED, THE PARTIES ACKNOWLEDGE THAT THE DAMAGES ARE DIFFICULT
OR  IMPOSSIBLE  TO  DETERMINE,   OTHERWISE   OBTAINING  AN  ADEQUATE  REMEDY  IS
INCONVENIENT AND THE LIQUIDATED DAMAGES CONSTITUTE A REASONABLE APPROXIMATION OF
THE HARM OR LOSS.


                                       19

                                   ARTICLE 12
                                  FORCE MAJEURE

     12.1 Definition.

     (a) As used in this  Agreement,  "Force Majeure" means any cause beyond the
reasonable  control  of,  and  without  the fault or  negligence  of,  the Party
claiming  Force  Majeure.  A Force Majeure shall  include,  without  limitation,
sabotage,  strikes,  riots or civil  disturbance,  acts of God, acts of a public
enemy, drought, earthquake, flood, explosion, fire, lightning, landslide, or any
similar cataclysmic occurrence,  or appropriation or diversion of electricity by
sale or order of any governmental  authority having  jurisdiction  thereof,  but
only if and to the extent that the event adversely  affects the  availability of
the PJM Transmission  System or BGE distribution  facilities,  and such affected
facilities are necessary to deliver Full Requirements Service electricity to the
meters of customers  taking Price Freeze  Service,  Default  Service and Special
Contract Service.

     (b) An  event  that  affects  the  availability  or cost of  operating  any
transmission or distribution  facilities  outside the PJM Control Area,  affects
the availability or cost of operating a generating  facility,  or any event that
merely  causes an economic  hardship to either Party shall not be deemed a Force
Majeure.

     12.2 Performance Excused.

     (a) If either  Party is  rendered  wholly or partly  unable to perform  its
obligations under this Agreement because of Force Majeure as defined above, that
Party  shall be excused  from  whatever  performance  is  affected  by the Force
Majeure, to the extent so affected, provided that:

          (i) the non-performing Party promptly, but in no case longer than five
     (5) Business  Days after the  occurrence  of the Force  Majeure,  gives the
     other Party written notice describing the particulars of the occurrence;

          (ii) the suspension of performance shall be of no greater scope and of
     no longer duration than is reasonably required by the Force Majeure;

          (iii) the  non-performing  Party uses reasonable efforts to remedy its
     inability to perform and  expeditiously  takes reasonable action to correct
     or cure the event or condition; and

          (iv) the  non-performing  Party  exercises all  reasonable  efforts to
     mitigate or limit  damages to the other  Party.  With  respect to Supplier,
     this  shall  mean  that  Supplier  must  purchase,   at  its  own  expense,
     electricity  from  the  PJM  market  to meet  its  obligations  under  this
     Agreement, to the extent such electricity is available and deliverable.

     (b) Neither  Party to this  Agreement  will be required by the foregoing to
settle a strike  affecting it except when,  according  to its  judgment,  such a
settlement is advisable.  Nothing in

                                       20


this Article 12 will excuse BGE from making payment for services  provided under
this Agreement.


                                   ARTICLE 13
                         REPRESENTATIONS AND WARRANTIES

     Each Party  represents and warrants to the other Party that: (i) it is duly
organized,  validly  existing  and  in  good  standing  under  the  laws  of the
jurisdiction  of  its  formation,   (ii)  except  for  the  Required  Regulatory
Approvals,  it has all  regulatory  authorizations  necessary  for it to legally
perform  its  obligations  under  this  Agreement  and any  other  documentation
relating to this Agreement to which it is a party, (iii) the execution, delivery
and performance of this Agreement and any other  documentation  relating to this
Agreement  to  which  it is a party  are  within  its  powers,  have  been  duly
authorized  by all  necessary  action  and do not  violate  any of the terms and
conditions in its governing  documents,  any contracts to which it is a party or
any law,  rule,  regulation,  order  or the like  applicable  to it,  (iv)  this
Agreement and each other document executed and delivered in accordance with this
Agreement  constitutes  its  legally  valid and binding  obligation  enforceable
against it in accordance with its terms,  except as such  enforceability  may be
limited by  bankruptcy,  insolvency or other laws  affecting the  enforcement of
creditors'  rights  and by  general  principles  of  equity,  (v)  there  are no
Bankruptcy Proceedings pending or being contemplated by it or, to its knowledge,
threatened  against  it,  (vi)  there  is not  pending  or,  to  its  knowledge,
threatened  against it or any of its Affiliates any legal proceedings that could
materially  adversely  affect its ability to perform its obligations  under this
Agreement  or any other  document  relating to this  Agreement  to which it is a
party except as disclosed in BGE's or BGE's parent  company's  Form 10-Q for the
quarterly period ended March 31, 2000 or Annual Report for the fiscal year ended
December 1999, as well as the proceedings listed on Appendix C hereto, and (vii)
no Event of Default or event which,  absent a cure, with the giving of notice or
lapse of time, or both,  would constitute an Event of Default with respect to it
has occurred and is continuing and no such event or circumstance  would occur as
a result of its entering into or performing its obligations under this Agreement
or any other document relating to this Agreement.

                                   ARTICLE 14
                                  MISCELLANEOUS

     14.1 Regulatory Action.

     If after  the  Effective  Date,  the FERC or any  court  or  agency  having
jurisdiction  over this  Agreement,  finds any term or  condition  to be unjust,
unreasonable  or  otherwise  unlawful,  the Parties  shall enter into good faith
negotiations  of such  changes  as are  reasonably  required  to  conform to the
requirements of law.

                                       21

     14.2 Assignment.

     Neither Party shall assign this Agreement or its rights  hereunder  without
the prior written consent of the other Party;  provided,  however,  either Party
may,  without the consent of the other Party (and without  relieving itself from
liability  hereunder),  (i)  transfer,  sell,  pledge,  encumber  or assign this
Agreement or the accounts,  revenues or proceeds  hereof in connection  with any
financing  or  other  financial  arrangements,  (ii)  transfer  or  assign  this
Agreement to an Affiliate of such Party which  Affiliate's  creditworthiness  is
comparable  to or higher  than that of such Party,  or (iii)  transfer or assign
this Agreement to any person or entity succeeding to all or substantially all of
the assets of such Party;  provided,  however,  that in each such case, any such
assignee shall agree to in writing be bound by the terms and conditions hereof.

     14.3 Compliance With Laws.

     At all times during the term of this  Agreement,  the Parties  shall comply
with all laws, rules,  requisitions,  and codes of all governmental  authorities
having  jurisdiction  over  each of their  respective  businesses  which are now
applicable,  or may be applicable hereafter,  including without limitation,  all
special laws, policies,  ordinances,  or regulations now in force, as amended or
hereafter enacted.  The Parties hereto shall maintain all licenses,  permits and
other consents from all  governmental  authorities  having  jurisdiction for the
necessary use and operation of their respective  business.  Nothing herein shall
be deemed a waiver of the Parties'  right to challenge  the validity of any such
law, rule or regulation.

     14.4 Choice of Law and Jurisdiction.

     THIS AGREEMENT AND THE RIGHTS AND DUTIES OF THE PARTIES  HEREUNDER SHALL BE
GOVERNED BY AND CONSTRUED, ENFORCED AND PERFORMED IN ACCORDANCE WITH THE LAWS OF
THE STATE OF MARYLAND,  WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAW. Except
as provided in Section 14.11, all disputes hereunder or relating hereto shall be
resolved  in the  Federal or State  courts of  Maryland  and each  Party  hereby
irrevocably  submits to the in personam  jurisdiction of such courts. Each Party
herein  waives  its  respective  right to any jury  trial  with  respect  to any
litigation arising under or in connection with this Agreement.

     14.5 Counterparts to this Agreement.

     This Agreement may be executed in any number of counterparts  each of which
shall be an original,  but all of which  together  shall  constitute one and the
same instrument.

     14.6 Notices.

     All notices,  requests,  statements or payments  shall be made as specified
below. Notices required to be in writing shall be delivered by letter, facsimile
or other  documentary form. Notice by facsimile or hand delivery shall be deemed
to  have  been  received  by the  close  of the  Business  Day on  which  it was
transmitted or hand delivered (unless transmitted or hand delivered after close

                                       22

in which  case it shall be deemed  received  at the  close of the next  Business
Day).  Notice by overnight mail or courier shall be deemed to have been received
two  Business  Days  after it was sent.  A Party may  change  its  addresses  by
providing notice of same in accordance herewith:

To CPS:
- -------
NOTICES & CORRESPONDENCE:              PAYMENTS:
- ------------------------               ---------
Constellation Power Source, Inc.       Federal Wire Transfer
General Counsel                        ***
111 Market Place, Suite 500            ***
Baltimore, Maryland  21202             Account: Constellation Power Source, Inc.
FAX No.: (410) 468-3540                ***
Phone No.: (410) 468-3490

INVOICES:                              CREDIT AND COLLECTIONS:
- --------                               ----------------------
Attn.: Operations                      Treasurer
FAX No.: (410)  468-3540               FAX No. (410) 468-3540
Phone No.: (410) 468-3430              Phone No.: (410) 468-3410

SCHEDULING:
- ----------
Attn: Operations
FAX No.: (410) 468-3540
Phone No.:  (410) 468-3430


To BGE:
- -------

NOTICES & CORRESPONDENCE:               PAYMENTS:
- ------------------------                --------
Baltimore Gas and Electric Company      Federal Wire Transfer
General Counsel                         ***
39 W. Lexington Street                  ***
Baltimore, Maryland 21201               Account: Baltimore Gas And Electric
                                           Company
FAX No.: (410) 234-7043                 ***
Phone No.: (410) 234-5805

INVOICES:                               CREDIT AND COLLECTIONS:
- --------                                ----------------------
Attn:  Director - Electric Supply       Treasurer
FAX No.: (410) 597-6403                 FAX No.: (410) 783-3619
Phone No.: (410) 597-6422               Phone No.: (410) 783-3610



*** The asterisk  denotes that  confidential  portions of this exhibit have been
omitted in reliance on Rule 24 b-2 of the  Securities  Exchange Act of 1934. The
confidential  portions  have been  submitted  separately to the  Securities  and
Exchange Commission.


                                      23


SCHEDULING:
- ----------
Attn:  Director - Electric Supply
FAX No.: (410) 597-6403
Phone No.: (410) 597-6422



     14.7 Confidentiality.

     Each Party agrees that it will treat in strictest confidence all documents,
materials,  and other information marked  "Confidential" or "Proprietary" by the
disclosing  Party  ("Confidential  Information")  which it shall  have  obtained
regarding the other Party during the course of the negotiations  leading to, and
its performance of, this Agreement (whether obtained before or after the date of
this Agreement). Confidential Information shall not be communicated to any third
person (other than to the receiving Party's counsel,  accountants,  financial or
tax advisors, or in connection with its financings);  provided that in the event
the  receiving  Party is required by law,  regulation or court order to disclose
any  Confidential  Information,  the receiving  Party will  promptly  notify the
disclosing  Party in  writing  prior to making any such  disclosure  in order to
facilitate  the  disclosing   Party's  seeking  a  protective   order  or  other
appropriate  remedy  from the proper  authority  and further  provided  that the
receiving Party further agrees that if the disclosing Party ultimately discloses
such Confidential Information to the requesting legal body, it will furnish only
that portion of the Confidential  Information which is legally required and will
exercise all reasonable efforts to obtain reliable  assurances that confidential
treatment will be accorded the Confidential Information.

     14.8 General.

     This Agreement  (including the Appendices  hereto)  constitutes  the entire
agreement  between the Parties  relating to the subject matter  contemplated  by
this  Agreement.  The Agreement shall be considered for all purposes as prepared
through the joint efforts of the parties and shall not be construed  against one
party or the other as a result of the preparation,  substitution,  submission or
other event of  negotiation,  drafting or  execution  hereof.  No  amendment  or
modification  to this Agreement  shall be enforceable  unless reduced to writing
and  executed  by both  Parties.  This  Agreement  shall not  impart  any rights
enforceable  by any  third-party  (other than a permitted  successor or assignee
bound to this Agreement). No waiver by a Party of any default by the other Party
shall be construed as a waiver of any other default.  Any provision  declared or
rendered  unlawful by any applicable court of law or regulatory agency or deemed
unlawful  because of a statutory  change will not otherwise affect the remaining
lawful  obligations  that arise under this Agreement.  The term "including" when
used  in this  Agreement  shall  be by way of  example  only  and  shall  not be
considered  in any way to be in  limitation.  The  headings  used herein are for
convenience  and reference  purposes  only. All indemnity and audit rights shall
survive the termination of this Agreement for two years.

                                       24


     14.9 Advisor.

     Goldman Sachs Power LLC ("GSP") is the  exclusive  advisor to CPS and not a
principal of CPS. From time to time,  CPS may designate one or more employees of
GSP  as  CPS'  agent  for  purposes  of  entering  into  this   Agreement   with
Counterparty.  CPS shall be solely  responsible  for any and all obligations and
liabilities  associated with this Agreement.  Neither GSP, Goldman,  Sachs & Co.
nor J. Aron & Company, nor any of their affiliates,  has any responsibility for,
or liability  with  respect to any  liabilities  of CPS under this  Agreement or
otherwise.

     14.10 Changes in Rates, Charges, Terms or Conditions.

     Each  Party  hereby  waives  its  rights to seek any  change to the  rates,
charges,  terms and conditions contained in this Agreement under Sections 205 or
206 of the Federal Power Act, as either  section may be amended or superseded or
to support a complaint  or other  judicial,  regulatory  or  legislative  action
seeking a change in this  Agreement,  absent  mutual  written  agreement  of the
Parties.  It is the intent of this Section that, to the maximum extent permitted
by law, the rates, charges,  terms and conditions of this Agreement shall not be
subject to change,  regardless  of whether such change is sought (a) by the FERC
acting sua sponte on behalf of a Party or a third party,  (b) by a Party, (c) by
a third party, or (d) in any other manner.

     14.11 Arbitration Proceedings.

     Any  dispute  or  need of  interpretation  arising  out of  this  Agreement
pertaining to the  calculation  of a Termination  Payment or a payment  required
pursuant to Articles 6 or 7 may be  submitted  upon  request of either  Party to
binding  arbitration by one  arbitrator who has not previously  been employed by
either Party, and does not have a direct or indirect interest in either Party or
the  subject  matter of the  arbitration.  Such  arbitrator  shall  either be as
mutually agreed by the Parties within thirty (30) days after written notice from
either Party requesting  arbitration,  or failing  agreement,  shall be selected
under the expedited rules of the American  Arbitration  Association (the "AAA").
Such arbitration  shall be held in alternating  locations of the home offices of
the Parties,  commencing with  Supplier's home office,  or in any other mutually
agreed  upon  location.  The  rules of the AAA  shall  apply to the  extent  not
inconsistent  with  the  rules  herein  specified.  Either  Party  may  initiate
arbitration  by written notice to the other Party and the  arbitration  shall be
conducted according to the following: (a) not later than seven (7) days prior to
the hearing  date set by the  arbitrator  each Party shall submit a brief with a
single  proposal  for  settlement,  (b) the  hearing  shall  be  conducted  on a
confidential basis without continuance or adjournment,  (c) the arbitrator shall
be limited to selecting only one of the two proposals  submitted by the Parties,
(d) each Party shall divide  equally the cost of the  arbitrator and the hearing
and each  Party  shall be  responsible  for its own  expenses  and  those of its
counsel and  representatives  and (e) evidence concerning the financial position
or organizational  make-up of the Parties,  any offer made or the details of any
negotiation  prior  to  arbitration  and  the  cost  to  the  Parties  of  their
representatives and counsel shall not be permissible.  Each Party agrees that it
will not bring a lawsuit  concerning  any  dispute  covered by this  arbitration
provision.  Any monetary award of the arbitrator may be enforced by the Party in
whose favor such monetary award is made in any court of competent jurisdiction.

                                       25


     14.12 Audit.

     Each Party has the right,  at its sole  expense and during  normal  working
hours,  to  examine  the  records of the other  Party to the  extent  reasonably
necessary to verify the accuracy of any statement,  charge or  computation  made
pursuant to this  Agreement.  If  requested,  a Party shall provide to the other
Party  statements   evidencing  the  quantities  of  Full  Requirements  Service
delivered at the Delivery Point. If any such examination  reveals any inaccuracy
in any statement,  the necessary  adjustments in such statement and the payments
thereof will be made  promptly and shall bear interest at the Interest Rate from
the date the overpayment or underpayment was made until paid; provided, however,
that no adjustment for any statement or payment will be made unless objection to
the accuracy thereof was made prior to the lapse of 12 months from the rendition
thereof.


                                       26

     IN WITNESS  WHEREOF,  the Parties hereto have executed this Agreement as of
the date set forth at the beginning of this Agreement.



                                  BALTIMORE GAS AND ELECTRIC COMPANY



                                  By:  _______________________________________
                                  Name:  Christian H. Poindexter
                                  Title:    President & Chief Executive Officer


                                  CONSTELLATION POWER SOURCE, INC.



                                  By:  _______________________________________
                                  Name:  John R. Collins
                                  Title:    Vice President & Treasurer


                                       27



                                                                      APPENDIX A
                                                                              TO
                                                               FULL REQUIREMENTS
                                                               SERVICE AGREEMENT


                                 SAMPLE PJM BILL











                                       A-1

                                                                      APPENDIX B
                                                                              TO
                                                               FULL REQUIREMENTS
                                                               SERVICE AGREEMENT


                           Price Freeze Service Prices
                          for Full Requirements Service


                   Prices stated in dollars per megawatt-hour

***         ***                    ***                   ***              ***




*** The asterisk  denotes that  confidential  portions of this exhibit have been
omitted in reliance on Rule 24 b-2 of the  Securities  Exchange Act of 1934. The
confidential  portions  have been  submitted  separately to the  Securities  and
Exchange Commission.





                                       B-1




                                                                      APPENDIX C
                                                                              TO
                                                               FULL REQUIREMENTS
                                                               SERVICE AGREEMENT


                              LITIGATION DISCLOSURE

1.   Request of the Mid-Atlantic  Power Supply  Association for Rehearing to the
     Federal Energy Regulatory  Commission in Baltimore Gas and Electric Co., et
     al., Docket No. EC000-57-000, dated April 28, 2000.

2.   Request of the Mid-Atlantic  Power Supply Association for Rehearing Federal
     Energy  Regulatory  Commission  in Baltimore  Gas and Electric Co., et al.,
     Docket No. ER00-1598-000, dated April 28, 2000.

3.   Request of Shell Energy, LLC for Rehearing to the Federal Energy Regulatory
     Commission  in  Baltimore  Gas  and  Electric  Co.,  et  al.,   Docket  No.
     EC000-57-000, dated May 23, 2000.

4.   Appeal to the Court of Special  Appeals of  Maryland,  dated May 19,  2000,
     from the judgment of the Circuit Court for Baltimore City, Maryland,  dated
     May 18, 2000, in the Petition of Mid-Atlantic  Power Supply Association for
     Judicial  Review  of the  Decision  of the  Public  Service  Commission  of
     Maryland in the Case of the Baltimore Gas and Electric  Company's  Proposed
     (A) Stranded Cost Quantification Mechanism; (B) Price Protection Mechanism;
     and (C)  Unbundled  Rates Case No. 8794 and in the Case of the  Petition of
     the Office of People's  Counsel for a Reduction in the Rates and Charges of
     Baltimore   Gas  and   Electric   Company,   Case  No.   8804   (Case   No.
     24-C-00-000666).

5.   Motion for Stay of the Maryland Public Service  Commission  Order No. 75757
     in the Circuit  Court for  Baltimore  City,  Maryland,  in the  Petition of
     Mid-Atlantic  Power Supply  Association for Judicial Review of the Decision
     of the Public  Service  Commission of Maryland in the Case of the Baltimore
     Gas and  Electric  Company's  Proposed  (A)  Stranded  Cost  Quantification
     Mechanism; (B) Price Protection Mechanism; and (C) Unbundled Rates Case No.
     8794 and in the Case of the Petition of the Office of People's  Counsel for
     a Reduction in the Rates and Charges of Baltimore Gas and Electric Company,
     Case No. 8804 (Case No. 24-C-00-000666).


                                       C-1