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                                  Exhibit 10
                                  ----------


                               TRANSACTION NO. 4
                                     UNDER
         THE PURCHASE AND SALE AGREEMENT FOR UNFORCED CAPACITY, ENERGY
        AND ANCILLARY SERVICES BETWEEN CONECTIV ENERGY SUPPLY, INC. AND
                        DELMARVA POWER & LIGHT COMPANY


Date:   September 1, 2001

Seller: Conectiv Energy Supply, Inc. ("CESI" or "Seller")

Buyer:  Delmarva Power & Light Company ("DPL" or "Buyer")

A.      General Terms and Conditions: This Transaction is executed under the
        Purchase and Sale Agreement for Unforced Capacity, Energy and Ancillary
        Services Between Conectiv Energy Supply, Inc. and Delmarva Power & Light
        Company (the "Umbrella Agreement"). Except as herein specifically
        modified, the terms and conditions of the Umbrella Agreement are
        incorporated herein by reference.

B.      Intent: The intent of this Transaction is that, with adjustments
        described below, CESI will provide to DPL its full supply-related
        requirements. During each month of the Term of this Transaction CESI
        will sell to DPL, and DPL will purchase from CESI, sufficient Energy,
        Supply-related Ancillary Services and Unforced Capacity (the "Products")
        to meet the DPL supply-related requirements as described herein. It is
        further the intent of the parties that CESI's costs to fulfill its
        obligations under this Transaction will not be flowed-through directly
        or indirectly to DPL, but will be solely CESI's responsibility and that
        the price that DPL will pay to CESI for the Products purchased in any
        month hereunder shall be equal to the supply-related components of the
        invoices rendered by DPL in said month.

C.      Term: September 1, 2001 through January 31, 2002; provided, however,
        that if all required regulatory approvals are obtained, the term shall
        be extended until June 30, 2004.

D.      Definitions for use in this Transaction:

        "DPL's DEMEC Obligations" shall mean quantities of Products that DPL
        sells to the Delaware Municipal Electric Corporation ("DEMEC") or to the
        Delaware Cities and Towns of Clayton, Smyrna, New Castle, Newark,
        Middletown, Milford, Lewes, and Seaford (referred to jointly herein as
        the "DEMEC Members") under contracts scheduled to expire on December 31,
        2003 (the "DEMEC Agreements").

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        "DPL's PLR Obligations" shall mean quantities of Products that DPL sells
        to retail customers ("PLR Customers") who have not selected service from
        a competitive supplier, have not entered into Special Contracts (as
        defined below) with Delmarva and whom DPL is obligated to serve as a
        supplier of last resort under the Delaware SOS, Maryland ESS or Virginia
        Retail tariffs. DPL's PLR Obligations, according to state jurisdiction
        and customer class, are follows:

               Delaware:
                     September 1, 2001 through September 30, 2002, all customer
                     classes October 1, 2002 through September 30, 2003,
                     residential customers only

               Maryland:
                     September 1, 2001 through June 30, 2003, all customer
                     classes July 1, 2003 through June 30, 2004, residential
                     customers only

               Virginia:
                     September 1, 2001 through December 31, 2003, all customer
                     classes

        "DPL's Special Contract Obligations" shall mean quantities of Products
        that DPL sells to retail customers ("Special Contract Customers") under
        contracts ("Special Contracts") approved by a state regulatory
        commission having jurisdiction over Delmarva's service. DPL's Special
        Contract Obligations shall be limited to base quantities of Products
        provided for in the Special Contracts and shall be further limited to
        the term provided for in each Special Contract as of the effective date
        of this Transaction.

        "DPL Supply Related Revenues" shall mean the supply component of
        revenues billed in any month by DPL to (i) DEMEC and the DEMEC Members;
        (ii) Special Contract Customers; and (iii) PLR Customers.

        "Non-DPL Obligations" shall mean quantities of Products that appear on
        either the PJM Invoice (Energy and Supply Related Ancillary Services) or
        the Installed Capacity Position Report (Unforced Capacity) as DPL
        consumption but which are not associated with DPL's DEMEC Obligations,
        DPL's Special Contract Obligations or DPL's PLR Obligations. Examples of
        Non-DPL Obligations are: (i) Usage by the City of Dover; (ii) Sales by
        third party suppliers to retail or wholesale customers within the DPL
        service territory; and (iii) Sales by DPL to PLR Customers during
        periods within the Term of this Transaction but outside of the periods
        defined in this Section for DPL's PLR Obligation.

        "PJM" means the PJM Interconnection, LLC, or successor organization.

        "PJM Invoice" shall mean the invoice that is issued by PJM to DPL each
        month that reflects the quantities of Products that DPL consumed in the
        prior month.

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        "Supply-Related Ancillary Services" shall mean:

              a.  Scheduling, System Control and Dispatch Service (PJM and RTO)
              b.  Reactive Supply and Voltage Control Service
              c.  Regulation and Frequency Response Service
              d.  Energy Imbalance Service
              e.  Operating Reserve Service

   E.   Products:

        1.    Energy required to meet DPL's supply requirements
        2.    Supply-related Ancillary Services required to meet DPL's supply
              requirements
        3.    Unforced Capacity required to meet the DPL's supply requirements

   F.   Quantity:

        1.    During each month of the term of this Transaction CESI shall sell
              to DPL and DPL shall purchase from CESI the quantities of Products
              required by DPL to meet the requirements of its DEMEC, Special
              Contract and PLR Obligations.

              a.  Energy and Supply-related Ancillary Services sold by CESI and
                  purchased by DPL shall be equal to the Energy and Ancillary
                  Services appearing on the monthly PJM Invoice as being
                  attributable to DPL adjusted to eliminate (i) quantities of
                  Energy and Supply-related Ancillary Services associated with
                  Non-DPL Obligations; (ii) quantities of Energy and Supply-
                  related Ancillary Services that DPL purchases under an
                  agreement from a third party; (iii) quantities of Energy and
                  Supply-related Ancillary Services that DPL purchases from a
                  third party pursuant to a regulatory commission order or
                  requirement; (iv) quantities of Energy and Supply-related
                  Ancillary Services that DPL purchases from third parties
                  pursuant to a requirement of state or federal law, including
                  the Public Utility Regulatory Policies Act; and (v) quantities
                  of Energy and Supply-related Ancillary Services that DPL
                  purchases to meet a state or federal requirement that it
                  obtain a portfolio of contracts that include specific
                  characteristics, including but not limited to an order
                  requiring DPL to make available a PLR service that includes
                  "green power." With respect to subparts (iii) and (v), DPL
                  agrees that it will not seek to obtain such a Commission
                  order, but reserves the right to enter into settlement
                  agreements that may contain such requirements.

              b.  Unforced Capacity sold by CESI and purchased by DPL shall be
                  equal to the Unforced Capacity appearing on the daily PJM
                  Installed Capacity Position Report as being attributable to
                  DPL, adjusted to eliminate (i) quantities of Unforced Capacity
                  associated with Non-DPL Obligations; (ii) quantities of
                  Unforced Capacity that DPL purchases under an agreement from a
                  third party; (iii) quantities of Unforced Capacity that

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                  DPL purchases from a third party pursuant to a regulatory
                  commission order or requirement; (iv) quantities of Unforced
                  Capacity that DPL purchases from third parties pursuant to a
                  requirement of state or federal law, including the Public
                  Utility Regulatory Policies Act; and (v) quantities of
                  Unforced Capacity that DPL purchases to meet a state or
                  federal requirement that it obtain a portfolio of contracts
                  that include specific characteristics, including but not
                  limited to an order requiring DPL to make available a PLR
                  service that includes "green power." With respect to subparts
                  (iii) and (v), DPL agrees that it will not seek to obtain such
                  a Commission order, but reserves the right to enter into
                  settlement agreements that may contain such requirements.

        2.   Nothing herein shall be deemed to prevent DPL from increasing its
             supply requirements either through (i) modification to the existing
             terms of the Special Contracts; (ii) modification to the existing
             terms of the DEMEC or DEMEC Member Agreements; (iii) supply to
             DEMEC or the DEMEC Members under the Part I Power Block or the
             energy component of the Part III Power Block of the DEMEC
             Agreements; or (iv) extension of the term during which it is
             obligated to serve PLR Customers. All such increases in the DPL
             supply requirements shall be referred to herein as "Additional
             Requirements". CESI shall be obligated to sell to DPL quantities of
             Products required to meet the Additional Requirements only if the
             Parties specifically agree to the price and other terms related to
             such additional quantities of Products.

        3.   The effects of corrections, true-ups, and/or adjustments to the PJM
             Invoice or other quantities described in Section F or the Price
             described in Section G for prior periods will be reflected in the
             month in which such adjustments are booked by DPL.

   G.   Price:

        1.   The Price that DPL will pay to CESI for the Products supplied in
             any month during the term of this Transaction shall be equal to the
             DPL Supply Related Revenues as described in Section G(2) less
             adjustments described in Section G(3).

        2.   The DPL Supply Related Revenues in any month shall be equal to the
             sum of:

             a.   The unbundled line items appearing in Sections 1, 2, 3 and 4
                  of the example attached hereto as Attachment No. 1 shall be
                  allocated between "TUB", "CPD" and "CESI" as provided for on
                  said example. The sum of the amounts assigned to "CESI,"
                  appearing in the box entitled "DPL Grand Total" shall
                  constitute the DPL Supply Related Revenues associated with
                  Special Contract Customers and PLR Customers for said month.
                  changes in the allocation procedure appearing on attachment
                  no. 1 shall be agreed to by the parties if they will result in
                  a more precise calculation of the revenues associated with the
                  supply components of

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                DPL's PLR obligations and DPL'S special contract obligations.
                such a change will be required when, and if, certain rate
                classes within a jurisdiction are no longer part of DPL's PLR
                obligations; and

           b.   Revenues billed by DPL to DEMEC and to the DEMEC Members for the
                Part II Power Block and the demand component of Part III Power
                Block (as those terms are used in the DEMEC Member Agreements)
                shall constitute the DPL Supply Related Revenues associated with
                DEMEC and the DEMEC Members.

      3.   The Price provided for herein shall include credits to the DPL Supply
           Related Revenues for the following: (i) amounts paid by DPL to NRG
           for the Unforced Capacity under the NRG Unforced Capacity
           transaction; (ii) amounts paid by DPL to PECO for Unforced Capacity
           and Energy acquired by DPL under the PECO Peach Bottom Reciprocal
           Sale; (iii) amounts paid by DPL to NRG for the Energy acquired by DPL
           under the NRG 500 MWh/hr firm transaction (unless and until said
           transactions are assigned to CESI); (iv) amounts paid by DPL for
           Products purchased from a third party pursuant to a regulatory
           commission order or requirement; (v) amounts paid by DPL for Products
           purchased from third parties pursuant to a requirement of state or
           federal law, including the Public Utility Regulatory Policies Act;
           and (vi) amounts paid by DPL for Products purchased to meet a state
           or federal requirement that it obtain a portfolio of contracts that
           include specific characteristics, including but not limited to an
           order requiring DPL to make available a PLR service that includes
           "green power."

 H.   Delivery Point:     Energy delivered to the DPL Zone.

 I.   Other Conditions:

      1.   CESI shall be responsible for all congestion charges for all services
           provided to DPL under this Transaction irrespective of whether those
           congestion charges reflect differences in Locational Marginal Pricing
           between portions of PJM and the DPL Zone or reflect differences
           within the DPL Zone. Congestion charges will be deemed to equal the
           amount of congestion charges reflected on the PJM Invoice, adjusted
           only by congestion charges for Non-DPL Obligations. To the extent
           that DPL is allocated or otherwise obtains Fixed Transmission Rights
           ("FTRs") with respect to the Energy delivered by CESI to the DPL Zone
           for DPL's DEMEC, Special Contract and PLR Obligations, the economic
           value of those FTRs will be provided to CESI. Nothing herein
           precludes CESI from obtaining additional FTRs on its behalf. In
           furtherance of this provision, CESI agrees to supply to PJM at the
           appropriate time(s) its designated capacity resources that it will
           use to meet obligations hereunder and DPL agrees to supply to PJM at
           the appropriate time(s) its network load transmission and capacity
           requirements.

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     2.   The Parties agree that if, at any time during the term of this
          Transaction, CESI does not supply any of the Product to DPL that CESI
          is obligated to provide, and DPL is deemed by PJM or other entity to
          have acquired the Products from another source, CESI shall pay to DPL
          the amount billed to DPL by PJM or that third party.

     3.   DPL agrees to remain a Network Service Customer as that term is
          defined by PJM and pay for any transmission and/or distribution
          services from the Delivery Point to its customers.  To the extent that
          CESI incurs costs associated with transmission or transmission-related
          ancillary services from regions outside of PJM or point-to-point
          service within PJM, CESI shall be responsible for such costs.

J.   Payment Terms:

     As soon as reasonably practicable after the end of a calendar month, DPL
     shall provide to CESI its computations of the Price that it is required to
     pay for Products purchased hereunder and shall pay that amount to CESI.
     CESI shall have the right to audit the calculations. Any dispute shall be
     resolved through good faith discussions and negotiations by individuals at
     the Vice-President level. DPL and CESI agree to discharge mutual payment
     obligations due and owing to each other on the same date through netting,
     so that only the excess amount remaining due shall be paid by the Party who
     owes it.

K.   Information:

     As soon as reasonably practicable, DPL shall program and modify changes to
     its computerized systems so that DPL can post on its public web-site its
     energy usage for its PLR Obligations from the prior day.  CESI shall be
     responsible for forecasting the hourly capacity requirements and energy
     requirements for DPL's DEMEC, Special Contract and PLR Obligations.

L.   Miscellaneous Terms and Definitions:

     1.   Nothing herein shall be deemed to obligate DPL to assign or CESI to
          accept assignment of a supply contract that is in effect between DPL
          and a third party.

     2.   Required regulatory approvals means an order of the Virginia State
          Corporation Commission.

     3.   Unforced Capacity is defined consistently with the definition of such
          term as used by PJM.  To the extent that PJM begins to use different
          nomenclature, or modifies the method by which Unforced Capacity or the
          new term for a similar product is calculated, the parties intend that
          this Transaction continue in full force and effect with the new term
          or product being automatically substituted into this Transaction.

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     4.   DPL will be responsible for collecting and paying any state utility
          taxes related to the supply of its tariff and contract obligations.

     5.   The parties recognize that the structure of PJM may be substantially
          modified to include regions not currently within PJM. To the extent
          that such a restructuring results in a substantial economic hardship
          to either party, which hardship is the result of expanding the regions
          subject to the control of PJM or a successor organization and not the
          result of market forces, either party may terminate this Transaction
          by providing one-years' notice of termination, during which time, the
          parties will negotiate in good faith an adjustment to the Transaction
          to reflect the changed circumstances.

     6.   Terms can only be modified by mutual agreement of both parties.

     7.   This Agreement shall be void and without effect and with no continuing
          obligation on the part of either Party to the extent that a regulatory
          commission with jurisdiction issues a final, non-appealable order that
          prohibits such Agreement.


DELMARVA POWER & LIGHT COMPANY           CONECTIV ENERGY SUPPLY, INC.


By:    _________________                 By:     _________________
Name:  Joseph M. Rigby                   Name:   William H. Spence
Title: Sr. Vice President                Title:  Sr. Vice President

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