Document:

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                                                                   Exhibit 10-21

                           PRODUCER - CUSTOMER NMP-2
                           REVENUE SHARING AGREEMENT

     This Revenue Sharing Agreement ("Agreement"), dated as of the 11th day of
December, 2000, by and between Constellation Nuclear, LLC, ("PRODUCER"), a
Maryland limited liability company with offices located at 39 West Lexington
Street, 18th Floor, Baltimore, MD 21201, and Niagara Mohawk Power Corporation
("CUSTOMER"), a New York corporation with offices located at 300 Erie Boulevard
West, Syracuse, NY 13202 (PRODUCER and CUSTOMER are each referred to herein as a
"Party", and collectively as the "Parties").

W I T N E S S E T H:
-------------------

     WHEREAS, PRODUCER and CUSTOMER have entered into an Asset Purchase
Agreement pursuant to which CUSTOMER has agreed to sell and PRODUCER has agreed
to purchase, certain interests in the Nine Mile Point Unit 2 Nuclear Generating
Station ("NMP-2"), dated December 11, 2000 (the "NMP-2 APA");

     WHEREAS, simultaneously with the execution of this Agreement, PRODUCER and
CUSTOMER have entered into a Power Purchase Agreement of even date herewith
pursuant to which PRODUCER has agreed to sell and CUSTOMER has agreed to
purchase certain energy and installed capacity from NMP-2 (the "NMP-2 PPA"); and

     NOW, THEREFORE, in consideration of these premises, the mutual agreements
set forth herein and other good and valuable consideration, and intending to be
legally bound, the Parties agree as follows:

     1.   DEFINITIONS.

          1.1  "Contract Month" shall mean each consecutive calendar month
               starting with the calendar month in which the Effective Date
               occurs and ending with (but including) the calendar month during
               which the Agreement expires.

          1.2  "Contract Quarter" shall mean each consecutive period comprised
               of three (3) consecutive Contract Months beginning with the
               Contract Month in which the Effective Date occurs. If the
               Agreement does not expire on the last day of a Contract Month,
               then the Contract Month during which the Agreement expires shall
               constitute a Contract Quarter.

          1.3  "Effective Date" shall mean the first full day after the
               expiration or termination of the NMP-2 PPA pursuant to its terms.

                                       1
<PAGE>

          1.4  "Energy" shall mean a quantity of electricity that is bid,
               produced, consumed, sold, or transmitted over a period of time,
               and measured or calculated in megawatt hours (MWh).

          1.5  "Floor Price" shall mean the price as defined in Section 4.3 of
               this Agreement.

          1.6  "Interest Rate" shall mean, for any date, the interest equal to
               the prime rate of Citibank as may from time to time be published
               in The Wall Street Journal under "Money Rates".

          1.7  "Market Capacity Price" shall mean the price as defined in
               Section 4.3 of this Agreement.

          1.8  "Market Energy Price" shall mean the price as defined in Section
               4.3 of this Agreement.

          1.9  "Market Price" shall mean the price as defined in Section 4.3 of
               this Agreement.

          1.10 "Monthly Price Adjustment" shall mean the value as calculated
               under Section 4.3 of this Agreement.

          1.11 "Monthly "New York Independent System Operator" or "NYISO" shall
               mean the organization formed in accordance with orders of the
               Federal Energy Regulatory Commission to administer the operation
               of, to provide equal access to, and to maintain the reliability
               of the bulk-power transmission system in New York State, or any
               successor organization.

          1.12 "Negative Price Adjustment Amount" shall mean the value as
               calculated under Section 4.4 of this Agreement.

          1.13 "Net Electric Output" shall mean the Energy production generated
               by NMP-2 less (a) the Energy used to operate NMP-2, but excluding
               Off-site Power Service used to operate NMP-2 as defined in the
               NMP-2 ICA, and (b) the Energy used in the transformation and
               transmission of electric power to the Delivery Point, provided
               that for purposes of this Agreement, such Net Electric Output
               shall not be less than zero.

          1.14 "Positive Price Adjustment Amount" shall mean the value as
               calculated under Section 4.5(i) of this Agreement.

          1.15 "Price Adjustment" shall mean the value as calculated under
               Section 4.3 of this Agreement.

                                       2
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     2.   CONDITION PRECEDENT. It is a condition precedent to the obligations of
PRODUCER and CUSTOMER under this Agreement that the Closing shall have occurred.

     3.   TERM. The term ("Term") of this Agreement shall begin on the Effective
Date and shall expire at 12:00, midnight, prevailing Eastern Time as applicable
on the day that is exactly ten (10) years after the Effective Date.

     4.   PURCHASE PRICE ADJUSTMENT.

          4.1  As adjustments to the purchase price for NMP-2, PRODUCER shall
               pay to CUSTOMER the Price Adjustments as calculated in this
               Section 4. An example of the calculation and application of the
               Price Adjustment described in this Section 4 is set forth in
               Appendix A hereto.

          4.2  A Price Adjustment shall be calculated for each Contract Quarter
               starting with the Effective Date through the Term of this
               Agreement.

          4.3  The Price Adjustment for each Contract Quarter shall be equal to
               the sum of the Monthly Price Adjustments for each Contract Month
               in the Contract Quarter. The Monthly Price Adjustment for each
               Contract Month shall be calculated as follows:

               Monthly Price
               Adjustment =        [Market Price - (Floor Price x Monthly Base
                                   Price Factor)] x forty-one percent (41%) x
                                   (the sum of the Net Electric Output during
                                   each hour of the Contract Month up to a
                                   maximum total amount of Energy in each such
                                   hour of 1,148 MWh).

               where:

               Market Price =      Market Energy Price + Market Capacity Price
                                   for the respective Contract Month.

               Market
               Energy Price =      The average over all hours of the respective
                                   Contract Month of the day-ahead locational
                                   based market price ("LBMP") paid to producers
                                   for energy at the NMP-2 Delivery Point
                                   (defined in the NMP-2 Interconnection
                                   Agreement) specified and published by the
                                   NYISO or, if the NYISO does not specify or
                                   publish an LBMP for the NMP-2 Delivery Point,

                                       3
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                                   the LBMP specified and published by the NYISO
                                   for the region in which the NMP-2 Delivery
                                   Point is located. In the event the NYISO
                                   ceases to provide such prices, the Parties
                                   shall in good faith undertake commercially
                                   reasonable efforts to agree on a substitute
                                   indices to reflect the value of Energy
                                   located at the NMP-2 Delivery Point. Failure
                                   of the parties to agree to such alternative
                                   indices shall constitute a dispute to be
                                   resolved in accordance with the provisions of
                                   Section 5.4.

               Market
               Capacity Price =    The market value of the installed capacity of
                                   NMP-2, expressed in $/MWh. The measure will
                                   reflect the weighted average of the market
                                   prices paid to producers for installed
                                   capacity at the NMP-2 Delivery Point as
                                   published by the NYISO in its installed
                                   capacity auctions. Where Market Capacity
                                   Prices are posted in units of $/kW-month,
                                   such conversion to units of $/MWh shall be
                                   the result of the posted price in $/kW-month,
                                   multiplied by 41.66666, divided by the number
                                   of days in the month. (For example, if the
                                   posted price was $1.50 /kW-month for a month
                                   which is 30 days long, the $/MWh would be
                                   $2.0833/MWh [($1.50 x 41.6666)/30]. Note
                                   41.6666 = 1000kW/MWh/24 hours per day). In
                                   the event NYISO ceases to provide such
                                   prices, the Parties shall in good faith
                                   undertake commercially reasonable efforts to
                                   agree on a substitute indices to reflect the
                                   value of installed capacity located at the
                                   NMP-2 Delivery Point. Failure of the parties
                                   to agree to such alternative indices shall
                                   constitute a dispute to be resolved in
                                   accordance with the provisions of Section
                                   5.4.

               Floor Price =       Set forth in Schedule 1.

               Monthly Base
               Price Factor =      Set forth in Schedule 2.

          4.4  If the Price Adjustment for a Contract Quarter is negative,
               PRODUCER shall accrue eighty percent (80%) of that negative

                                       4
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               Price Adjustment (that 80% defined herein as the "Negative Price
               Adjustment Amount") to be credited against Positive Price
               Adjustment Amounts, if any, for subsequent Contract Quarters,
               thereby reducing such Positive Price Adjustment Amounts until the
               full amount of such Negative Price Adjustment Amounts has been so
               credited.

          4.5  If the Price Adjustment for a Contract Quarter is positive,
               PRODUCER shall:

               (i)   take 80% of that positive Price Adjustment (the 80% defined
                     herein as the "Positive Price Adjustment Amount"); then

               (ii)  credit against and reduce the Positive Price Adjustment
                     Amount by the sum of any Negative Price Adjustment Amounts
                     for prior Contract Quarters, to the extent that any such
                     Negative Price Adjustment Amounts have not been credited
                     against Positive Price Adjustment Amounts; then

               (iii) make payment of the Purchase Price Adjustment in an amount
                     equal to any Positive Price Adjustment Amount remaining
                     after crediting any Negative Price Adjustment Amounts as
                     described in (ii) above.

          4.6  Negative Price Adjustment Amounts calculated with respect to a
               Contract Quarter shall only be credited against Positive Price
               Adjustment Amounts, if any, for subsequent Contract Quarters.
               CUSTOMER shall have no obligation to make any payment to PRODUCER
               in respect of any Negative Price Adjustment Amount, whether by
               way of refund of payments made by PRODUCER in respect of Positive
               Price Adjustment Amounts for prior Contract Quarters, payment for
               Negative Price Adjustment Amounts which are not followed by
               Positive Price Adjustment Amounts against which such Negative
               Price Adjustment Amounts may be credited, or otherwise.

          4.7  Extraordinary Inflation: On each anniversary of the date hereof,
               if the United States Gross Domestic Product Implicit Price
               Deflator (as reported quarterly by the United States Department
               of Commerce; the "GDP Deflator") for the most recently reported
               quarterly period has increased by more than 5% from the same
               quarterly period in the prior year, the Floor Price for each
               subsequent Contract Year set forth in Schedule 1 hereof, shall be
               increased by the percentage amount such increase is greater than
               5%. For example, if on the first anniversary date hereof the GDP

                                       5
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               Deflator for the most recent quarter equals 112, and the GDP
               Deflator for the same quarter reported in the previous year was
               105, each Contract Year in Schedule 1 hereof shall be increased
               by 1.66%.

     5.   PAYMENT AND DISPUTES.

          5.1  Statements and Payments. PRODUCER shall prepare a statement
               ("Statement") for each Contract Quarter showing the Price
               Adjustment Payment due to CUSTOMER, if any, for such Contract
               Quarter and the calculation of the Price Adjustment Amount for
               such Contract Quarter (whether positive or negative). PRODUCER
               will provide to CUSTOMER such Statement on or before the tenth
               (10th) Business Day after the final Contract Month of each
               Contract Quarter. PRODUCER shall pay the amount due, if any, by
               wire transfer of immediately available funds to an account
               specified by CUSTOMER not later than the fifth (5th) Business Day
               after the date on which PRODUCER provides the Statement.

          5.2  Overdue Payments. Overdue payments shall accrue interest at the
               Interest Rate from, and including the due date to, but excluding,
               the date of payment.

          5.3  Billing Disputes. If CUSTOMER, in good faith, disputes any
               Statement or part thereof, CUSTOMER shall notify PRODUCER in
               writing of the basis for the dispute within ten (10) business
               days of receipt of the Statement. If it is subsequently
               determined by arbitration or agreed that an adjustment to the
               Statement is appropriate, PRODUCER will prepare and issue a
               revised Statement not later than ten (10) Business Days after it
               is determined that an adjustment is appropriate. Any Price
               Adjustment Payment due to CUSTOMER pursuant to the revised
               Statement shall be paid by wire transfer of immediately available
               funds to the account specified by CUSTOMER not later than three
               (3) Business Days from the date the revised Statement is issued
               and shall include interest accrued at the Interest Rate until the
               date paid.

          5.4  Dispute Resolution.

               5.4.1 All claims, disputes, and other matters concerning the
                     interpretation and enforcement of this Agreement, shall be
                     submitted to binding arbitration in New York, NY and shall
                     be heard by three neutral arbitrators under the Commercial
                     Arbitration Rules of the American Arbitration Association.

                                       6
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               5.4.2 Only the Parties hereto and their designated
                     representatives shall be permitted to participate in any
                     arbitration initiated pursuant to this Agreement. The
                     arbitration process shall be concluded not later than six
                     (6) months after the date that it is initiated. The award
                     of the arbitrators shall be accompanied by a reasoned
                     opinion if requested by either Party. The award rendered in
                     such a proceeding shall be final. The Parties shall keep
                     the award, and any opinion issued by the arbitrators,
                     confidential unless the Parties agree otherwise. Any award
                     of amounts due shall include interest accrued at the
                     Interest Rate until the date paid. Judgment may be entered
                     upon the arbitration opinion and award in any court having
                     jurisdiction.

               5.4.3 The procedures for the resolution of disputes set forth
                     herein shall be the sole and exclusive procedures for the
                     resolution of disputes. Each Party is required to continue
                     to perform its obligations under this Agreement pending
                     final resolution of a dispute. All negotiations pursuant to
                     these procedures for the resolution of disputes will be
                     confidential, and shall be treated as compromise and
                     settlement negotiations for purposes of the Federal Rules
                     of Evidence and State Rules of Evidence and similarly
                     applicable rules or regulations of any state or federal
                     regulatory agency with jurisdiction over a Party.

     6.   CONTRACT ADMINISTRATION AND OPERATION.

          6.1  Company Representative. PRODUCER and CUSTOMER shall each appoint
               a representative (collectively, the "Company Representatives"),
               who will be duly authorized to act on behalf of the Party that
               appoints him/her, and with whom the other Party may consult at
               all reasonable times, and whose instructions, requests, and
               decisions shall be binding on the appointing Party as to all
               matters pertaining to the administration of this Agreement.

          6.2  Record Retention and Access. PRODUCER and CUSTOMER shall each
               keep complete and accurate records and all other data required by
               either of them for the purpose of proper administration of this
               Agreement, including such records as may be required by state or
               federal regulatory authorities. All such records shall be
               maintained for a minimum of five (5) years after the creation of
               the record or data and for any additional length of time required
               by state or federal regulatory agencies with jurisdiction over
               PRODUCER or CUSTOMER. PRODUCER and CUSTOMER, on a

                                       7
<PAGE>

               confidential basis, will provide reasonable access to records
               kept pursuant to this Section of this Agreement. The Party
               seeking access to such records shall pay 100% of any out-of-
               pocket costs the other Party incurs to provide such access.

          6.3  Notices. All notices pertaining to this Agreement not explicitly
               permitted to be in a form other than writing shall be in writing
               and shall be given by same day or overnight delivery, electronic
               transmission, certified mail, or first class mail. Any notice
               shall be given to the other Party as follows:

               If to PRODUCER:

               Constellation Nuclear, LLC
               39 West Lexington Street
               18/th/ Floor
               Baltimore, MD 21201
               Attn: Robert E. Denton
               Title: President
               Phone: (410) 234-6149
               Facsimile: (410) 234-5323

               If to CUSTOMER:

               Niagara Mohawk Power Corporation
               300 Erie Boulevard West
               Attn: Clement E. Nadeau
               Title: Vice President
               Phone: (315) 428-6492
               Facsimile: (315) 428-5722

               If given by electronic transmission (including telex, facsimile
               or telecopy), notice shall be deemed given on the date received
               and shall be confirmed by a written copy sent by first class
               mail. If sent in writing by certified mail, notice shall be
               deemed given on the second business day following deposit in the
               United States mails, properly addressed, with postage prepaid. If
               sent by same-day or overnight delivery service, notice shall be
               deemed given on the day of delivery. PRODUCER and CUSTOMER may,
               by written notice to the other, change its representative(s)
               including its Company representative and the address to which
               notices are to be sent.

                                       8
<PAGE>

     7.   CONFIDENTIALITY. Except as otherwise required by law, the Parties
shall keep confidential the terms and conditions of this Agreement and the
transactions undertaken pursuant hereto. If a Party is required to file this
Agreement with any regulatory body or court, it shall seek trade secret or
similar protection from such authority and promptly notify the other Party.

     8.   GOVERNMENT REGULATION. This Agreement and all rights and obligations
of the Parties hereunder are subject to all applicable federal, state and local
laws and all duly promulgated orders and duly authorized actions of governmental
authorities having proper and valid jurisdiction over the terms of this
Agreement. Further, if at any time following receipt of any regulatory approvals
required for the initial effectiveness of the NMP-2 Sale, the New York Public
Service Commission, any legislature, any agency, or any court takes any action
relating to or affecting this Agreement, the payments required to be made
hereunder, or CUSTOMER's reflection in rates thereof, neither CUSTOMER or
PRODUCER shall have any right to seek damages from the other, to discontinue
performance under this Agreement, or to modify or seek to modify any of the
terms and conditions in any way as a consequence of such action.

     9.   GOVERNING LAW/CONTRACT CONSTRUCTION. This Agreement shall be
interpreted, construed, and governed by the law of the State of New York. For
purposes of contract construction, or otherwise, this Agreement is the product
of negotiation and neither Party to it shall be deemed to be the drafter of this
Agreement or any part hereof. The Section and Subsection headings of this
Agreement are for convenience only and shall not be construed as defining or
limiting in any way the scope or intent of the provisions hereof.

     10.  WAIVER AND AMENDMENT. Any waiver by either Party of any of the
provisions of this Agreement must be made in writing, and shall apply only to
the instance referred to in the writing, and shall not, on any other occasion,
be construed as a bar to, or a waiver of, any right either Party has under this
Agreement. The Parties may not modify, amend, or supplement this Agreement
except by a writing signed by the Parties.

     11.  BINDING EFFECT; NO THIRD-PARTY RIGHTS OR BENEFITS. This Agreement is
entered into solely for the benefit of PRODUCER and CUSTOMER, and their
respective successors and permitted assigns, and therefore is not intended and
shall not be construed to confer any rights or benefits on any third-party.

     12.  ENTIRE AGREEMENT. This Agreement contains the complete and exclusive
agreement and understanding between the Parties as to its subject matter.

     13.  ASSIGNMENT. CUSTOMER shall have right to assign the Agreement in whole
or in part without consent of PRODUCER. Partial assignments are subject to a 50-
MW minimum. PRODUCER shall not have the right to assign this Agreement

                                       9
<PAGE>

without CUSTOMER's prior written consent, provided that PRODUCER or its
                                          --------
permitted assignee, without CUSTOMER's consent, may assign, transfer, pledge or
otherwise dispose of (absolutely or as security) its rights and interests
hereunder to an Affiliate (an "Assignee Entity") of PRODUCER at least 68% of the
equity securities of which are owned by PRODUCER; provided, however, (i) any
                                                  --------  -------
minority owner of the Assignee Entity shall be that entity contemplated to
become an equity owner of PRODUCER's affiliated merchant energy group as set
forth in that certain press release issued by Constellation Energy Group on
October 23, 2000, (ii) no minority owner of the Assignee Entity may have any
control or management or operational rights or role with respect to the Assignee
Entity , and (iii) no such assignment shall relieve or discharge PRODUCER from
any of its obligations hereunder or shall be made if it would reasonably be
expected to prevent or materially impede, interfere with or delay the
transactions contemplated by this Agreement or materially increase the costs of
the transactions contemplated by this Agreement.

     14.  SIGNATORS' AUTHORITY/COUNTERPARTS. The undersigned certify that they
are authorized to execute this Agreement on behalf of their respective Parties.
This Agreement may be executed in two or more counterparts, each of which shall
be an original. It shall not be necessary in making proof of the contents of
this Agreement to produce or account for more than one such counterpart.

     15.  NO DEDICATION OF FACILITIES. No undertaking by PRODUCER or CUSTOMER
under any provision of this Agreement shall be deemed to constitute the
dedication of any portion of NMP-2 to the public, to CUSTOMER, or to any other
entity.

     IN WITNESS WHEREOF, and intending to be legally bound, the Parties have
executed this Agreement by the undersigned duly authorized representatives as of
the date first stated above.

PRODUCER                               CUSTOMER

By:_________________________           By:_______________________

Name:_______________________           Name:_____________________

Title:______________________           Title:____________________

                                       10
<PAGE>

SCHEDULE 1
----------
Floor Price
-----------

<TABLE>
<S>           <C>    <C>    <C>    <C>    <C>    <C>    <C>    <C>    <C>    <C>
Contract Year     1      2      3      4      5      6      7      8      9     10

Floor Price   40.75  41.57  42.40  43.25  44.11  44.99  45.89  46.81  47.75  48.70
($/MWh)
</TABLE>

SCHEDULE 2
----------
Monthly Base Price Factor
-------------------------

For every year of the Term:

                      ----------------------------------
                                             BASE PRICE
                         MONTH                FACTOR
                      ----------------------------------
                       January                0.9176
                      ----------------------------------
                       February               0.9192
                      ----------------------------------
                       March                  0.7729
                      ----------------------------------
                       April                  0.7707
                      ----------------------------------
                       May                    1.0461
                      ----------------------------------
                       June                   1.1687
                      ----------------------------------
                       July                   1.3861
                      ----------------------------------
                       August                 1.4450
                      ----------------------------------
                       September              1.1275
                      ----------------------------------
                       October                0.7801
                      ----------------------------------
                       November               0.7707
                      ----------------------------------
                       December               0.8954
                      ----------------------------------

                                       11<PAGE>

                                                                   Exhibit 10-22

                          PRODUCER - CUSTOMER NMP - 2
                           POWER PURCHASE AGREEMENT

     This Power Purchase Agreement (this "Agreement"), dated as of December 11,
2000 by and between Constellation Nuclear, LLC, ("PRODUCER"), a Maryland limited
liability company with offices located at 39 West Lexington Street, 18th Floor,
Baltimore, MD 21201, and Niagara Mohawk Power Corporation ("CUSTOMER"), a New
York company with offices located at 300 Erie Boulevard West, Syracuse, NY 13202
(PRODUCER and CUSTOMER are each referred to herein as a "Party", and
collectively as the "Parties").

WITNESSETH:
----------

     WHEREAS, PRODUCER and CUSTOMER have entered into an Asset Purchase
Agreement pursuant to which CUSTOMER has agreed to sell and PRODUCER has agreed
to purchase, certain interests in the Nine Mile Point Unit No. 2 Nuclear
Generating Station ("NMP-2"), dated December 11, 2000 (the "NMP-2 APA");

     WHEREAS, PRODUCER and CUSTOMER have entered into an Asset Purchase
Agreement pursuant to which CUSTOMER has agreed to sell and PRODUCER has agreed
to purchase, certain interests in Nine Mile Point Unit No. 1 Nuclear Generating
Station ("NMP-1"), dated December 11, 2000 (the "NMP-2 APA");

     WHEREAS, simultaneously with the execution of this Agreement, PRODUCER,
Niagara Mohawk Power Corporation ("Niagara Mohawk") and New York State Electric
& Gas Company ("NYSEG") have executed an Interconnection Agreement of even date
with this Agreement (the "NMP-2 ICA") governing the terms of interconnection of
NMP-2 with the Transmission System, as that term is defined in the NMP-2 ICA;
and

     WHEREAS, simultaneously with the execution of this Agreement, PRODUCER and
CUSTOMER have executed a Revenue Sharing Agreement of even date with this
Agreement governing certain adjustments to the purchase price for NMP-2 (the
"NMP-2 RSA").

     NOW, THEREFORE, in consideration of these premises, the mutual agreements
set forth herein and other good and valuable consideration, and intending to be
legally bound, the Parties agree as follows:

1.   DEFINITIONS. In addition to the terms defined elsewhere herein, the
     following capitalized terms shall have the meaning stated below when used
     in this Agreement:

     1.1. "Ancillary Services" shall mean those services necessary to support
          the transmission of Energy from generators to loads, while maintaining
          reliable operation of the New York State power system in accordance
          with Good Utility Practice and reliability rules. Ancillary Services
          include

                                      -1-
<PAGE>

          scheduling, system control and dispatch service, reactive supply and
          voltage support service, regulation and frequency response service,
          energy imbalance service, operating reserve service (including
          spinning reserve, 10-minute non-synchronized reserves and 30-minute
          reserves), and black start capability, and as defined in Section 2.16
          of the NYISO Market Administration and Control Area Services Tariff,
          as amended or superseded from time to time.

     1.2. "Bilateral Transaction" shall mean a transaction between two or more
          parties for the purchase and/or sale of Installed Capacity, Energy,
          and/or Ancillary Services other than those in the ISO Administered
          Markets, and as defined in Section 2.16 of the NYISO Market
          Administration and Control Area Services Tariff, as amended or
          superseded from time to time.

     1.3. "Capability Period" shall mean six-month periods which are established
          as follows: (1) from May 1 through October 31 of each year (Summer
          Capability Period); and (2) from November 1 of each year through April
          30 of the following year (Winter Capability Period), as defined in
          Section 2.17 of the NYISO Market Administration and Control Area
          Services Tariff, as amended or superseded from time to time.

     1.4. "Closing" shall have the meaning set forth in the NMP-2 APA.

     1.5. "Contract Year" shall mean each twelve (12) month period during the
          Term (as defined in Section 3 hereof) starting with the Effective
          Date. For the purposes of this Agreement, the first month of the Term
          starts on the Effective Date and ends on the last calendar day of the
          first full calendar month following the Effective Date. All subsequent
          months during the Term are calendar months.

     1.6. "Contract Year Base Price" shall mean the prices so identified in
          Schedule A.

     1.7. "Day-Ahead Market" (DAM) shall mean the NYISO administered market in
          which Energy and/or Ancillary Services are scheduled and sold day-
          ahead consisting of the day-ahead scheduling process, price
          calculations and settlements, as defined at Definition 1.7d of the
          NYISO OATT, as amended or superseded from time to time.

     1.8. "DAM Scheduled Net Electric Output" shall mean, for any hour,
          scheduled electric output with the NYISO in the DAM Market pursuant to
          Article 5.3, which shall be the Day-Ahead-Market expected Energy
          production generated by NMP-2 less (a) the Energy used to operate NMP-
          2, but excluding Off-site Power Service used to operate NMP-2 as
          defined in the NMP-2 ICA, and (b) the Energy used in the
          transformation and

                                      -2-
<PAGE>

           transmission of electric power to the Delivery Point, provided that
           for purposes of this Agreement, such DAM Scheduled Net Electric
           Output shall not be less than zero. Such DAM Scheduled Net Electric
           Output shall be estimated using Good Utility Practice and shall
           approximate as accurately as reasonably possible the expected Net
           Electric Output.

     1.9.  "Delivery Point" shall mean the "Delivery Points" as that term is
           defined in the NMP-2 ICA and as indicated on the one-line diagram
           included as part of Schedule A to the NMP-2 ICA.

     1.10. "Dependable Maximum Net Capability" (DMNC) shall mean the sustained
           maximum net output of a generator, as demonstrated by the performance
           of a test or through actual operation, averaged over a continuous
           period of time, and as defined in Section 2.40 of the NYISO Market
           Administration and Control Area Services Tariff, as amended or
           superseded from time to time.

     1.11. "Dependable Maximum Net Capability Test" (DMNC Test) shall mean a
           test performed in accordance with and as defined in Section 2.40 of
           the NYISO Services Tariff, as amended or superseded from time to
           time.

     1.12. "Effective Date" shall mean the date of the Closing.

     1.13. "Energy" shall mean a quantity of electricity that is bid, produced,
           consumed, sold, or transmitted over a period of time, and measured or
           calculated in megawatt hours (MWh).

     1.14. "First Hour" shall mean that full or portion of an hour occurring
           from the moment that the Parties jointly declare the NMP-2 APA
           consummated to the beginning of the next hour.

     1.15. "Good Utility Practice" shall mean any of the practices, methods and
           acts engaged in or approved by a significant portion of the electric
           utility industry during the relevant time period, or any of the
           practices, methods and acts which, in the exercise of reasonable
           judgment in light of the facts known at the time the decision was
           made, could have been expected to accomplish the desired result at a
           reasonable cost consistent with good business practices, reliability,
           safety, expedition and compliance with applicable law and
           regulations. Good Utility Practice is not intended to be limited to
           the optimum practice, method, or act, to the exclusion of all others,
           but rather to be practices, methods, or acts generally accepted in
           the electric utility industry. Good Utility Practices shall include,
           where applicable, but not be limited to North American Electric
           Reliability Council ("NERC") criteria, guidelines, rules and
           standards, Northeast Power Coordinating Council ("NPCC") criteria,
           guidelines, rules and standards, New York State Reliability Council
           ("NYSRC") criteria, guidelines, rules

                                      -3-
<PAGE>

           and standards, if any, and NYISO criteria, guidelines, rules and
           standards, as they may be amended from time to time including the
           rules, guidelines and criteria of any successor organization of the
           foregoing entities. When applied to PRODUCER, the term Good Utility
           Practice shall also include standards applicable to a generator were
           the generator a utility generator connecting to the distribution or
           transmission facilities or system of another utility.

     1.16. "Installed Capacity" shall mean a generator or load facility that
           complies with the requirements of the reliability rules and is
           capable of supplying and/or reducing the demand for Energy in the New
           York Control Area for the purpose of ensuring that sufficient Energy
           and capacity are available to meet the reliability rules, as defined
           at Definition 1.14 of the NYISO OATT, as amended or superseded from
           time to time. The Installed Capacity requirement, established by the
           New York State Reliability Counsel and the NYISO, and applied by and
           through the NYISO OATT, includes a margin of reserve in accordance
           with the reliability rules.

     1.17. "Interest Rate" means, for any date, the interest equal to the prime
           rate of Citibank as may from time to time be published in The Wall
           Street Journal under "Money Rates".

     1.18. "Monthly Off-Peak Price" shall mean the product of (i) the Contract
           Year Base Price times (ii) the Off-Peak Monthly Price Factor for the
           respective Contract Years and calendar months, such prices and
           factors being set forth in Schedules A and B respectively.

     1.19. "Monthly On-Peak Price" shall mean the product of (i) the Contract
           Year Base Price times (ii) the On-Peak Monthly Price Factor for the
           respective Contract Years and calendar months, such prices and
           factors being set forth in Schedules A and B, respectively.

     1.20. "New York Control Area" (NYCA) shall have the meaning as defined
           Section 1.13 of the NYISO Market Administration and Control Area
           Services Tariff, as amended or superseded from time to time.

     1.21. "New York Independent System Operator" (NYISO) shall mean the not-
           for-profit corporation established in accordance with orders of the
           Federal Energy Regulatory Commission to administer the operation of,
           to provide equal access to, and to maintain the reliability of the
           bulk-power transmission system in New York State, or any successor
           organization.

     1.22. "NYISO OATT" shall mean the New York Independent System Operator Open
           Access Transmission Tariff revised as of 12/27/99, as amended and
           superseded from time to time.

                                      -4-
<PAGE>

     1.23. "NYISO Services Tariff" shall mean the New York Independent System
           Operator Market Administration and Control Area Services Tariff
           revised as of 11/17/99, as amended and superseded from time to time.

     1.24. "Net Electric Output" shall mean the Energy production generated by
           NMP-2 less (a) the Energy used to operate NMP-2, but excluding Off-
           site Power Service used to operate NMP-2 as defined in the NMP-2 ICA,
           and (b) the Energy used in the transformation and transmission of
           electric power to the Delivery Point, provided that for purposes of
           this Agreement, such Net Electric Output shall not be less than zero.

     1.25. "Off-Peak" shall mean the hours between 11:00 p.m. and 7:00 a.m.,
           prevailing Eastern Time, Monday through Friday, and all hours on
           Saturday and Sunday, and NERC-defined holidays, or as otherwise
           decided by the NYISO.

     1.26. "On-Peak" shall mean the hours between 7:00 a.m. and 11:00 p.m.
           inclusive, prevailing Eastern Time, Monday through Friday, except
           NERC-defined holidays, or as otherwise decided by the NYISO.

2.   CONDITION PRECEDENT. It is a condition precedent to the obligations of
     PRODUCER and CUSTOMER under this Agreement that the Closing shall have
     occurred.

3.   TERM. The term ("Term") of this Agreement shall begin on the Effective Date
     and shall expire at 12:00 midnight prevailing Eastern Time on the day that
     is exactly ten years after the last day of the month during which the
     Effective Date occurs. Notwithstanding any other provision of this
     Agreement, this Agreement shall become ineffective and shall terminate in
     the event the NMP-2 APA terminates.

4.   INSTALLED CAPACITY.

     4.1.  Sale of Installed Capacity. PRODUCER shall provide, and CUSTOMER
           shall accept, from the Effective Date through the end of the first
           Capability Period occurring during the Term an amount of Installed
           Capacity equal to the product of (i) forty-one percent (41%) times
           (ii) ninety percent (90%) of the DMNC of NMP-2 during the first
           Capability Period occurring during the Term (up to a maximum of 1,140
           MW for the Summer Capability Period and 1,155 MW for the Winter
           Capability Period). PRODUCER shall provide, and CUSTOMER shall
           accept, from the end of the first Capability Period occurring during
           the Term through the end of the last Capability Period occurring
           during the Term an amount of Installed Capacity equal to the product
           of (i) forty-one percent (41%) times (ii) ninety percent (90%) of the
           seasonal DMNC of NMP-2 up to a maximum

                                      -5-
<PAGE>

          of 1,140 MW for the Summer Capability Period and 1,155 MW for the
          Winter Capability Period.

     4.2. Performance. PRODUCER shall use good faith efforts to ensure that the
          Installed Capacity for NMP-2 is as high as practicable, consistent
          with the Energy generated by the plant. In no event, however, will
          PRODUCER be required to contract for, or take any other measure to
          obtain, additional installed capacity to satisfy its obligations under
          this Section. In accordance with NYISO requirements, PRODUCER shall
          perform DMNC Tests and PRODUCER shall use good faith efforts to
          maximize the output of the plant during such tests. The Parties will
          coordinate the scheduling of such tests.

5.   ENERGY.

     5.1. Sale of Energy. During the Term of this Agreement, PRODUCER shall
          deliver, and CUSTOMER shall accept, an amount of Energy equal to the
          product of (i) forty-one percent (41%) times (ii) ninety percent (90%)
          times (iii) the DAM Scheduled Net Electric Output or, if applicable,
          the Net Electric Output during each hour of the Term up to a maximum
          total amount of Energy in each such hour of 1,148 MWh.

     5.2. Performance. Except as provided in Section 5.3.1, PRODUCER shall have
          no obligation to produce or deliver any amount of Energy hereunder.
          If for any reason which is not prohibited by this Agreement PRODUCER
          generates an insufficient amount of Energy at the facilities to be
          able to deliver the amount specified in section 5.1 hereof, PRODUCER
          shall have no obligation to sell or deliver, and CUSTOMER shall have
          no obligation to buy or accept, the portion of the amount specified in
          section 5.1 not generated by PRODUCER, or any replacement Energy.

     5.3. Scheduling. CUSTOMER shall have the option, exercisable at its sole
          discretion and upon written notice twenty-four (24) hours in advance
          of the NYISO's scheduling requirement for provision of the DAM
          schedule to PRODUCER to: (i) have PRODUCER deliver and schedule DAM
          Scheduled Net Electric Output as provided in section 5.3.1 below; or
          (ii) have PRODUCER deliver and CUSTOMER schedule Net Electric Output
          as provided in Section 5.3.2 below.

       5.3.1. DAM Scheduled Net Electric Output. Notwithstanding Section 5.2,
              PRODUCER shall provide the NYISO with a request for a Bilateral
              Transaction schedule in the Day-Ahead Market, in accordance with
              the NYISO Market Administration and Control Area Services Tariff,
              for the DAM Scheduled Net Electric Output to be delivered to
              CUSTOMER under this Agreement. PRODUCER shall be solely
              responsible for all charges imposed by the NYISO as a result of
              any failure by

                                      -6-
<PAGE>

              PRODUCER to deliver the amount of DAM Scheduled Net Electric
              Output specified in the Bilateral Transaction schedule.

       5.3.2. Net Electric Output. CUSTOMER shall effectuate the scheduling with
              the NYISO for Net Electric Output delivered by PRODUCER to
              CUSTOMER under this Agreement.

       5.3.3. Mitigation. The Party scheduling a Bilateral Transaction with the
              NYISO shall be obligated to mitigate any charges or penalties
              imposed by the NYISO on the non-scheduling Party.

     5.4. Other Costs. With regard to DAM Scheduled Net Electric Output or, if
          applicable, Net Electric Output delivered by PRODUCER to CUSTOMER
          pursuant to this Agreement at the Delivery Point, except as the NMP-2
          ICA provides, PRODUCER shall bear no cost or liability for the DAM
          Scheduled Net Electric Output or, if applicable, Net Electric Output
          beyond the Delivery Point.

     5.5. Title and Risk of Loss. Title and risk of loss transfers from PRODUCER
          to CUSTOMER upon receipt of the DAM Scheduled Net Electric Output or,
          if applicable, Net Electric Output by CUSTOMER from PRODUCER at the
          Delivery Point.

     5.6. Taxes. Taxes applicable to the DAM Scheduled Net Electric Output or,
          if applicable, Net Electric Output delivered by PRODUCER to CUSTOMER
          pursuant to this Agreement, or to transactions involving such DAM
          Scheduled Net Electric Output or, if applicable, Net Electric Output,
          (other than taxes based on PRODUCER's and/or CUSTOMER's net income),
          shall be borne by CUSTOMER if related to or arising after receipt at
          the Delivery Point of such DAM Scheduled New Electric Output or, if
          applicable, Net Electric Output, and shall be borne by PRODUCER if
          related to or arising before receipt at the Delivery Point of such DAM
          Scheduled New Electric Output or, if applicable, Net Electric Output.

     5.7. Outages. PRODUCER shall schedule and perform all plant outages
          consistent with Good Utility Practice, and in accordance with the
          terms of the NMP-2 ICA. PRODUCER shall provide CUSTOMER with as much
          advance notice as possible of scheduled outages, unscheduled outages,
          power reductions, and deratings. Except as reasonably required by Good
          Utility Practice, PRODUCER shall not schedule any portion of a
          refueling outage during the months of June, July, August, or
          September.

                                      -7-
<PAGE>

6.   OTHER PRODUCTS AND SALES. Nothing herein shall preclude PRODUCER from
     selling any Ancillary Service, Energy, Installed Capacity or other product
     or service or quantity thereof associated with NMP-2 to a third party or
     the NYISO not needed to fulfill PRODUCER's obligations hereunder.

7.   PRICE. The price during each hour of the Term for such amount of Installed
     Capacity and Energy as is provided pursuant to Article 4 and Article 5
     respectively of this Agreement, shall be determined using the data set
     forth in Schedules A and B. The amounts payable by CUSTOMER to PRODUCER
     shall be calculated monthly, and shall be equal to the sum of the product
     of (i) the DAM Scheduled Net Electric Output or, if applicable, Net
     Electric Output in MWh delivered by PRODUCER to CUSTOMER each hour times
     (ii) the applicable price for each hour as determined from Schedules A and
     B for all hours of the month. No other amount shall be payable by CUSTOMER
     for Installed Capacity or Energy provided by PRODUCER pursuant to this
     Agreement.

8.   BILLINGS AND PAYMENTS.

     8.1. Payment. PRODUCER shall provide CUSTOMER with an invoice setting forth
          the quantity of Energy (MWh), as recorded by the Revenue Meters
          defined and provided for in the NMP-2 ICA, which was delivered to
          CUSTOMER in the indicated month, on or before the 5/th/ day of each
          month for the preceding monthly period. CUSTOMER shall remit the
          amount due by wire transfer, or as otherwise agreed, pursuant to
          PRODUCER's invoice instructions, on the later of fifteen days from
          receipt of PRODUCER's invoice or the twenty-fifth (25/th/) day of the
          calendar month in which the invoice is rendered. In the event the
          25/th/ is a weekend day or a holiday on which banking institutions are
          not open in New York State, then payment shall be made upon the
          following business day.

     8.2. Overdue Payments. Overdue payments shall accrue interest at the
          Interest Rate from, and including, the due date to, but excluding, the
          date of payment.

     8.3. Billing Dispute. If CUSTOMER, in good faith, disputes an invoice,
          CUSTOMER shall notify PRODUCER in writing within ten (10) business
          days of receipt of the invoice of the basis for the dispute and pay
          the portion of such statement not in dispute no later than the due
          date. If any amount withheld under dispute by CUSTOMER is ultimately
          determined (under the terms herein) to be due to PRODUCER, it shall be
          paid within three (3) business days of such determination along with
          interest accrued at the Interest Rate until the date paid. Inadvertent
          overpayments shall be returned by PRODUCER upon request or deducted by
          PRODUCER from subsequent invoices, with interest accrued at the
          Interest Rate until the date paid or deducted.

                                      -8-
<PAGE>

     8.4. Mutual Rights of Offset. PRODUCER hereby acknowledges and agrees that,
          if an "Event of Default" has occurred under the promissory note(s)
          (such Event as defined therein) executed by PRODUCER in favor of
          CUSTOMER at the Closing (the "Note"), CUSTOMER shall have the right to
          offset and/or net any payments then owed by PRODUCER under the Note in
          relation to the NMP-1 APA and the NMP-2 APA against any payments or
          other amounts due from CUSTOMER to PRODUCER under this Agreement, or
          the NMP-1 Power Purchase Agreement. CUSTOMER hereby acknowledges and
          agrees that, if CUSTOMER is deemed to be in default hereunder (as
          defined herein in Section 9.1.3 hereof), then PRODUCER may offset
          and/or net payments then owed by CUSTOMER hereunder against any
          payments or other amounts due from PRODUCER to CUSTOMER under the
          Note. Notwithstanding the foregoing, if pursuant to Section 14 of the
          Note, a Surety Bond, Letter of Credit or other financial assurance
          shall have been provided by CUSTOMER under the Note, PRODUCER's right
          of offset shall be deemed to no longer apply to the Note, and shall
          apply only to such Surety Bond, Letter of Credit or other financial
          assurance.

9.   DEFAULT, TERMINATION AND LIABILITY.

     9.1. Breach, Cure and Default.

       9.1.1. Breach. A breach of this Agreement shall occur upon the failure by
              a Party to perform or observe any material term or condition of
              this Agreement as described in Section 9.1.2. of this Agreement.

       9.1.2. Events of Breach. A breach of this Agreement shall include: (a)
              the failure to pay any amount due, unless such amount is disputed
              in compliance with Section 8.3 of this Agreement; (b) the failure
              to comply with any material term or condition of this Agreement;
              (c) the appointment of a receiver, liquidator or trustee for a
              Party, or of any property of a Party, if such receiver, liquidator
              or trustee is not discharged within sixty (60) days; (d) the entry
              of a decree adjudicating a Party bankrupt or insolvent if such
              decree is continued undischarged and unstayed for a period of
              sixty (60) days; and (e) the filing by a Party of a voluntary
              petition in bankruptcy under any provision of any federal or state
              bankruptcy law.

       9.1.3. Cure and Default. Upon a Party's breach of its obligations under
              this Agreement, (except for breaches described in (c), (d), and
              (e) of Section 9.1.2, whose occurrence shall constitute a default
              by the Party), the other Party (hereinafter the "Non-Breaching
              Party") shall give such Party in breach (the "Breaching Party") a
              written notice specifying the nature of the breach, describing the
              breach in reasonable detail, and demanding that the Breaching
              Party cure such

                                      -9-
<PAGE>

              breach. The Breaching Party shall be deemed to be in default of
              its obligations under this Agreement (i) if it fails to cure its
              breach within thirty (30) days after its receipt of such notice,
              (ii) where the breach is such that it cannot be cured within
              thirty (30) days after its receipt of such notice, the Breaching
              Party does not in good faith commence within thirty (30) days all
              such steps as are commercially reasonable efforts that are
              necessary and appropriate to cure such breach and thereafter
              diligently pursue such steps to completion, or (iii) where the
              breach cannot be cured within any commercially reasonable period
              of time.

       9.1.4. Remedies upon Default. Upon a Party's default as described in
              Section 9.1.3, the non-defaulting Party may, at its option (i)
              continue performance under this Agreement and exercise such other
              rights and remedies as it may have in equity, at law or under this
              Agreement; or (ii) terminate this Agreement in accordance with
              Section 9.2 hereof.

       9.1.5. Waiver. No provision of this Agreement may be waived except by
              mutual agreement of the Parties as expressed in writing and
              executed by each Party. Any waiver that is not in writing and
              executed by each Party shall be null and void from its inception.
              No express waiver in any specific instance as provided in a
              required writing shall be construed as a waiver in future
              instances unless specifically so provided in the required writing.
              No express waiver of any specific default shall be deemed a waiver
              of any other default whether or not similar to the default waived,
              or a continuing waiver of any other right or default by a Party.
              The failure of any Party to insist in any one or more instances
              upon the strict performance of any of the provisions of this
              Agreement, or to exercise any right herein, shall not be construed
              as a waiver or relinquishment for the future of such strict
              performance of such provision or the exercise of such right.
              Further, delay by any Party in enforcing its rights under this
              Agreement shall not be deemed a waiver of such rights.

     9.2. Termination. If a Breaching Party is deemed to be in default as
          described in Section 9.1.3, then the Non-Breaching Party may terminate
          this Agreement by providing ten (10) days advanced written notice to
          the Party in default. Termination of this Agreement shall not relieve
          any Party of any of their liabilities and obligations arising
          hereunder prior to the date termination becomes effective.

     9.3. Additional Remedies. A Party's right to terminate as the result of an
          occurrence of a default of any other Party shall not serve to limit
          the rights such non-defaulting Party may have under law or equity as a
          result of such default.

                                      -10-
<PAGE>

     9.4.  Mitigation of Damages. A non-defaulting Party has a duty to mitigate
           damages in the event of a default. The provisions of this Section 9.4
           shall survive termination of this Agreement.

     9.5.  Exclusion of Damages. In no event will either Party be liable under
           this Agreement, or under any cause of action relating to the subject
           matter of this Agreement, for any special, indirect, incidental,
           punitive, exemplary or consequential damages, including but not
           limited to loss of profits or revenues, loss of use of any property,
           cost of substitute equipment, facilities or services, downtime costs
           or claims of third parties for such damages, except to the extent
           that such damages arise from the gross negligence or intentional
           misconduct of the Party from whom such damages are sought. The
           provisions of this Section 9.5 shall survive termination of this
           Agreement.

10.  CONTRACT ADMINISTRATION AND OPERATION.

     10.1. Party Representatives. PRODUCER and CUSTOMER shall each appoint a
           representative who will be duly authorized to act on behalf of the
           Party that appoints him/her, and with whom the other Party may
           consult at all reasonable times, and whose instructions, requests,
           and decisions shall be binding on the appointing Party as to all
           matters pertaining to the administration of this Agreement.

     10.2. Record Retention and Access. PRODUCER and CUSTOMER shall each keep
           complete and accurate records and all other data required by either
           of them for the purpose of proper administration of this Agreement,
           including such records as may be required by state or federal
           regulatory authorities or the NYISO. All such records shall be
           maintained for a minimum of five (5) years after the creation of the
           record or data and for any additional length of time required by
           state or federal regulatory agencies with jurisdiction over PRODUCER
           or CUSTOMER. PRODUCER and CUSTOMER, on a confidential basis, will
           provide reasonable access to records kept pursuant to this Section of
           this Agreement. The Party seeking access to such records shall pay
           100% of any out-of-pocket costs the other Party incurs to provide
           such access.

     10.3. Notices. All notices pertaining to this Agreement not explicitly
           permitted to be in a form other than writing shall be in writing and
           shall be given by same day or overnight delivery, electronic
           transmission, certified mail, or first class mail. Any notice shall
           be given to the other Party as follows:

           If to PRODUCER:

           Constellation Nuclear, LLC
           39 West Lexington Street

                                      -11-
<PAGE>

          18th Floor
          Baltimore, MD. 21201
          Title: President
          Attn: Robert E. Denton
          Phone: (410) 234-6149
          Facsimile: (410) 234-5323

          If to CUSTOMER:

          Niagara Mohawk Power Corporation
          300 Erie Boulevard West
          Syracuse, NY 13202
          Title: Director of Energy Transactions
          Attn.: Scott Leuthauser
          Phone: (315) 428-6006
          Facsimile: (315) 428-6129

          If given by electronic transmission (including telex, facsimile or
          telecopy), notice shall be deemed given on the date received and shall
          be confirmed by a written copy sent by first class mail. If sent in
          writing by certified mail, notice shall be deemed given on the second
          business day following deposit in the United States mails, properly
          addressed, with postage prepaid. If sent by same-day or overnight
          delivery service, notice shall be deemed given on the day of delivery.
          PRODUCER and CUSTOMER may, by written notice to the other, change its
          representative(s), including its Company Representative, and the
          address to which notices are to be sent.

11.  BUSINESS RELATIONSHIP. Each Party shall be solely liable for the payment of
     all wages, taxes, and other costs related to the employment by such Party
     of persons who perform this Agreement, including all federal, state, and
     local income, social security, payroll and employment taxes and
     statutorily-mandated workers' compensation coverage. None of the persons
     employed by either Party shall be considered employees of the other Party
     for any purpose.

12.  CONFIDENTIALITY. Except as otherwise required by law, the Parties shall
     keep confidential the terms and conditions of this Agreement and the
     transactions undertaken hereto. If a Party is required to file this
     Agreement with any regulatory body or court, it shall seek trade secret
     protection from such authority and notify the other Party of the
     requirement.

13.  GOVERNMENT REGULATION. This Agreement and all rights and obligations of the
     Parties hereunder are subject to all applicable federal, state and local
     laws and all duly promulgated orders and duly authorized actions of
     governmental authorities having proper and valid jurisdiction over the
     terms of this Agreement. In addition, the rates, terms, and conditions
     contained in this Agreement are not

                                      -12-
<PAGE>

     subject to change under Section 205 of the Federal Power Act, as that
     section may be amended or superseded, absent the mutual written agreement
     of the Parties.

14.  GOVERNING LAW/CONTRACT CONSTRUCTION. This Agreement shall be interpreted,
     construed, and governed by the law of the State of New York. For purposes
     of contract construction, or otherwise, this Agreement is the product of
     negotiation and neither Party to it shall be deemed to be the drafter of
     this Agreement or any part hereof. The Section and Subsection headings of
     this Agreement are for convenience only and shall not be construed as
     defining or limiting in any way the scope or intent of the provisions
     hereof. Litigation of claims or disputes arising under this Agreement shall
     be brought in state or federal court in the State of New York.

15.  DISPUTE RESOLUTION.

     15.1. All claims, disputes, and other matters concerning the interpretation
           and enforcement of this Agreement, shall be submitted to binding
           arbitration in New York, NY and shall be heard by three neutral
           arbitrators under the Commercial Arbitration Rules of the American
           Arbitration Association.

     15.2. Only the Parties hereto and their designated representatives shall be
           permitted to participate in any arbitration initiated pursuant to
           this Agreement. The arbitration process shall be concluded not later
           than six (6) months after the date that it is initiated. The award of
           the arbitrators shall be accompanied by a reasoned opinion if
           requested by either Party. The award rendered in such a proceeding
           shall be final. The Parties shall keep the award, and any opinion
           issued by the arbitrators, confidential unless the Parties agree
           otherwise. Any award of amounts due shall include interest accrued at
           the Interest Rate until the date paid. Judgment may be entered upon
           the arbitration opinion and award in any court having jurisdiction.

     15.3. The procedures for the resolution of disputes set forth herein shall
           be the sole and exclusive procedures for the resolution of disputes.
           Each Party is required to continue to perform its obligations under
           this Agreement pending final resolution of a dispute. All
           negotiations pursuant to these procedures for the resolution of
           disputes will be confidential, and shall be treated as compromise and
           settlement negotiations for purposes of the Federal Rules of Evidence
           and State Rules of Evidence and similarly applicable rules or
           regulations of any state or federal regulatory agency with
           jurisdiction over a Party.

16.  WAIVER AND AMENDMENT. Any waiver by either Party of any of the provisions
     of this Agreement must be made in writing, and shall apply only to the
     instance referred to in the writing, and shall not, on any other occasion,
     be

                                      -13-
<PAGE>

     construed as a bar to, or a waiver of, any right either Party has under
     this Agreement. The Parties may not modify, amend, or supplement this
     Agreement except by a writing signed by the Parties.

17.  BINDING EFFECT; NO THIRD-PARTY RIGHTS OR BENEFITS. This Agreement is
     entered into solely for the benefit of PRODUCER and CUSTOMER, and their
     respective successors and permitted assigns, and therefore is not intended
     and shall not be construed to confer any rights or benefits on any third-
     party.

18.  ENTIRE AGREEMENT. This Agreement, including references to and incorporation
     of other agreements and tariffs, contains the complete and exclusive
     agreement and understanding between the Parties as to its subject matter.

19.  ASSIGNMENT. CUSTOMER shall have the right to assign the Agreement in whole
     or in part, subject to a 50 MW minimum, without the consent of the
     PRODUCER, (A) provided that (i) such assignee's long-term unsecured debt
     credit rating issue by Moody's Investors Service, Standard & Poor's
     Corporation or another nationally recognized rating agency is investment
     grade rated, and (ii) provided that the CUSTOMER's agreement with the
     assignee requires that for so long as the assignee's credit rating is
     reduced to the lesser of (a) below investment grade or (b) below its credit
     rating at the time of the assignment, the assignee shall deliver to
     PRODUCER, in a form reasonably satisfactory to PRODUCER, either (x) a
     guarantee of the assignee's obligations by its parent provided that such
     parent entity's long-term unsecured debt credit rating issue by Moody's
     Investors Service, Standard & Poor's Corporation or another nationally
     recognized rating agency is investment grade, or (y) an irrevocable,
     standby letter of credit issued by a banking or other financial
     institution, the long-term unsecured debt obligations of which is rated
     investment grade, with a drawing amount equal to the obligations under this
     Agreement which have been assigned to the assignee and then remain, and
     that such security remain in full force and effect until all amounts owed
     to the PRODUCER by the assignee are satisfied and paid in full (or such
     assignee establishes or reestablishes the lesser of (a) an investment grade
     rating or (b) its credit rating at the time of the assignment); and
     provided, however, that assignee may reduce the drawing amount under such
     letter of credit from time to time provided such drawing amount is not less
     than the aggregated amount of the obligations under this Agreement which
     have been assigned and then remain; or (B) to an entity that does not have
     an investment grade rating, provided that CUSTOMER's agreement with the
     assignee requires that the assignee deliver, in a form reasonably
     satisfactory to PRODUCER, an irrevocable, standby letter of credit issued
     by a banking or other financial institution, the long-term unsecured debt
     obligations of which is rated investment grade, with a drawing amount equal
     to the obligations under this Agreement which have been assigned to the
     assignee, and that such security remain in full force and effect until all
     amounts owed to the PRODUCER by the assignee are

                                      -14-
<PAGE>

     satisfied and paid in full (or such assignee establishes an investment
     grade rating); and provided, however, that assignee may reduce the drawing
     amount under such letter of credit from time to time provided such drawing
     amount is not less than the aggregated amount of the obligations under this
     Agreement which have been assigned and then remain. PRODUCER shall not have
     the right to assign this Agreement without CUSTOMER's prior written
     consent, provided that PRODUCER or its permitted assignee, without
              --------
     CUSTOMER's consent, may assign, transfer, pledge or otherwise dispose of
     (absolutely or as security) its rights and interests hereunder to an
     Affiliate (an "Assignee Entity") of PRODUCER at least 68% of the equity
     securities of which are owned by PRODUCER; provided, however, (i) any
                                                --------  -------
     minority owner of the Assignee Entity shall be that entity contemplated to
     become an equity owner of PRODUCER's affiliated merchant energy group as
     set forth in that certain press release issued by Constellation Energy
     Group on October 23, 2000, (ii) no minority owner of the Assignee Entity
     may have any control or management or operational rights or role with
     respect to the Assignee Entity , and (iii) no such assignment shall relieve
     or discharge PRODUCER from any of its obligations hereunder or shall be
     made if it would reasonably be expected to prevent or materially impede,
     interfere with or delay the transactions contemplated by this Agreement or
     materially increase the costs of the transactions contemplated by this
     Agreement. All assignments shall consist of the same proportion of
     Installed Capacity and Energy. Except as provided above, any authorized
     assignment shall relieve the assigning Party of any obligations or
     liability under the Agreement to the extent of the assignment.

20.  SIGNATORS' AUTHORITY/COUNTERPARTS. The undersigned certify that they are
     authorized to execute this Agreement on behalf of their respective Party.
     This Agreement may be executed in two or more counterparts, each of which
     shall be an original. It shall not be necessary in making proof of the
     contents of this Agreement to produce or account for more than one such
     counterpart.

21.  NO DEDICATION OF FACILITIES. No undertaking by PRODUCER or CUSTOMER under
     any provision of this Agreement shall be deemed to constitute the
     dedication of any portion of NMP-2 to the public, to CUSTOMER, or to any
     other entity.

22.  OPERATION OF NMP-2. PRODUCER at all times shall operate NMP-2 in accordance
     with Good Utility Practice.

                                      -15-
<PAGE>

     IN WITNESS WHEREOF, and intending to be legally bound, the Parties have
executed this Agreement by the undersigned duly authorized representatives as of
the date first stated above.

PRODUCER                           CUSTOMER

By:                                By:

Name:                              Name:

Title:                             Title:

DATE: December 11, 2000

<PAGE>

                                  SCHEDULE A

                          "Contract Year Base Prices"
                          ---------------------------

                          ---------------------------
                            Contract          Price
                              Year        ($ per MWh)
                          ---------------------------
                               1             $35.70
                          ---------------------------
                               2             $35.32
                           ---------------------------
                               3             $33.95
                           ---------------------------
                               4             $33.60
                           ---------------------------
                               5             $33.56
                           ---------------------------
                               6             $33.23
                           ---------------------------
                               7             $33.91
                           ---------------------------
                               8             $34.61
                           ---------------------------
                               9             $35.32
                           ---------------------------
                               10            $36.05
                          ---------------------------

<PAGE>

                                  SCHEDULE B

                            "Monthly Price Factors"
                            -----------------------

                   -------------------------------------------
                     Month           On-Peak         Off-Peak
                   -------------------------------------------
                    January           1.1865          0.6746
                   -------------------------------------------
                    February          1.1865          0.6746
                   -------------------------------------------
                     March            0.9492          0.6133
                   -------------------------------------------
                     April            0.9492          0.6133
                   -------------------------------------------
                      May             1.4238          0.7052
                   -------------------------------------------
                      June            1.6611          0.7359
                   -------------------------------------------
                      July            2.1357          0.7666
                   -------------------------------------------
                     August           2.1357          0.7666
                   -------------------------------------------
                    September         1.6611          0.7359
                   -------------------------------------------
                    October           0.9492          0.6133
                   -------------------------------------------
                    November          0.9492          0.6133
                   -------------------------------------------
                    December          1.1865          0.6746
                  -------------------------------------------

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