<PAGE>
                                                                   Exhibit 10.15

                                    AGREEMENT

     The parties to this Agreement (this "Agreement") are the undersigned
individual (the "Employee") and Allegheny Energy Supply LLC (the "Company") and
Allegheny Energy Global Markets LLC (the "Employer"). In connection with the
asset contribution and purchase agreement dated on or about January 4, 2001 (the
"Purchase Agreement") among the Company, Allegheny Energy, Inc. and Merrill
Lynch & Co., Inc., pursuant to which the Company will purchase the business and
assets of the Merrill Lynch Global Energy Markets Business as of the Closing
Date (as defined in the Purchase Agreement) the Employee and the Company entered
into an Employment Agreement, dated as of the Closing Date (the "Employment
Agreement"). The Employment Agreement contemplates that the Employee will become
employed by the Company as of the Closing Date. The parties now deem it
desirable for the Employee to be employed by the Employer instead of by the
Company, under equivalent terms and conditions to those set forth in the
Employment Agreement.

     Accordingly, intending to be legally bound, the parties acknowledge and
agree that:

     1. Subject to Section 2 below, the Company hereby assigns its rights and
obligations under the Employment Agreement to the Employer, and the Employee
hereby consents to such assignment.

     2. Notwithstanding the assignment set forth in Section 1 above:

          (a) The Company hereby irrevocably guarantees to the Employee the
prompt performance and payment of the obligations of the Employer to the
Employee under the Employment Agreement, including without limitation, the
indemnification provided for in Section 11 of the Employment Agreement. This is
a guarantee of performance and payment and not of collection only, and recourse
may be had in the first instance against the Company without first proceeding
against the Employer. The obligations of the Employer under this guarantee shall
not be affected or impaired by reason of the happening from time to time of any
event, including, without limitation, any of the following: (i) any failure,
omission or delay on the part of Employee to enforce, assert or exercise any
right conferred on the Employee in the Employment Agreement or otherwise or (ii)
any bankruptcy, insolvency or reorganization of, any arrangement or assignment
for benefit of creditors by, or any trusteeship with respect to the Company or
the Employer or any of their assets. The Company shall require any successor
(whether direct or indirect, by purchase, merger, consolidation or otherwise) to
all or substantially all of the business, assets or stock of the Company to
expressly assume the guarantee and to fulfill the obligations hereunder as if no
succession had taken place.

          (b) Section 6 of the Employment Agreement regarding the issuance to
the Employee of options to acquire equity interests in the Company shall
continue to apply in accordance with its terms. The Employee shall have no right
to acquire any equity interests in the Employer.

<PAGE>

     3. Section 13(a) of the Employment Agreement is hereby deemed amended to
the extent necessary to give full effect to the assignment contemplated by
Section 1 above.

     4. Section 1 of the Employment Agreement is amended by deleting the
reference to Section 4 and inserting therefore, Section 8.

     WITNESS the due execution hereof as of the day and year first above
written.

                                           ALLEGHENY ENERGY SUPPLY LLC


                                           By:
                                              ----------------------------------
                                              Name:
                                              Title:


                                           ALLEGHENY ENERGY GLOBAL MARKETS LLC


                                           By:
                                              ----------------------------------
                                              Name:
                                              Title:

                                           EMPLOYEE


                                           -------------------------------------

                                       2

<PAGE>

                            AMENDMENT AND ASSIGNMENT
                             OF EMPLOYMENT AGREEMENT

                                          , 2002
                                ----------

     The parties to this Amendment and Assignment of Employment Agreement (the
"Amendment and Assignment") are Allegheny Energy, Inc., a Maryland corporation
("Allegheny Energy"), Allegheny Energy Supply LLC, a Delaware limited liability
company ("Supply") and a majority-owned subsidiary of Allegheny Energy, and a
successor to Allegheny Energy Global Markets LLC, a Delaware limited liability
company (the "Global Markets"), Allegheny Energy Service Corporation, a Maryland
corporation (the "Employer") and a wholly-owned subsidiary of Allegheny Energy,
and                (the "Executive").
    --------------

     Supply and the Executive entered into an Employment Agreement, dated
           (the "Employment Agreement"). Subsequently, Supply and the Executive
----------
agreed to amend and assign the Employment Agreement to Global Markets, subject
to Supply's guarantee of Global Markets' obligations under the Employment
Agreement. The Employment Agreement provides for the grant of certain options to
the Executive to acquire membership interests in Supply. As of the date of this
Amendment and Assignment, Allegheny Energy is granting an option to the
Executive to acquire shares of Allegheny Energy, Inc. common stock pursuant to
the terms of a Stock Option Notice and subject to the provisions of the
Allegheny Energy, Inc. Long Term Incentive Plan (the "Allegheny Energy Option").
In consideration of the Allegheny Energy Option, the Executive agrees to waive
any and all rights to, and disclaim any and all interests in, any options to
purchase an interest in Supply as described in or otherwise contemplated under
the Employment Agreement and any such options shall be deemed canceled and void,
ab initio.

     Further, the parties deem it desirable for the Executive to be employed by
the Employer instead of Global Markets, effective as of January 1, 2002, under
equivalent terms and conditions to those set forth in the Employment Agreement,
as amended herein and as it may be amended from time to time.

     Accordingly, intending to be legally bound, the parties acknowledge and
agree that:

     1. Section 6 of the Employment Agreement is deleted and all references in
the Employment Agreement to Section 6 are deleted and of no further effect. The
Executive agrees and acknowledges that any grant or other issuance of any option
to purchase an interest in Supply, whether pursuant to the Employment Agreement
or otherwise, is hereby canceled and void, ab initio.

     2. Exhibit B attached to the Employment Agreement is deleted in its
entirety and all references in the Employment Agreement to Exhibit B are
deleted.

     3. Supply hereby assigns its rights and obligations under the Employment
Agreement to the Employer, effective January 1, 2002, and the Executive hereby
consents to such assignment.

     Notwithstanding the assignment set forth in the preceding paragraph, Supply
irrevocably guarantees to the Executive the prompt performance and payment of

<PAGE>

the obligations of the Employer to the Executive under the Employment Agreement,
including without limitation, the indemnification provided for in Section 11 of
the Employment Agreement. This is a guarantee of performance and payment and not
of collection only, and recourse may be had in the first instance against Supply
without first proceeding against the Employer. The obligations of the Employer
under this guarantee shall not be affected or impaired by reason of the
happening from time to time of any event, including, without limitation, any of
the following: (i) any failure, omission or delay on the part of Executive to
enforce, assert or exercise any right conferred on the Executive in the
Employment Agreement or otherwise or (ii) any bankruptcy, insolvency or
reorganization of, any arrangement or assignment for benefit of creditors by, or
any trusteeship with respect to the Employer or any of its assets. Supply shall
require any successor (whether direct or indirect, by purchase, merger,
consolidation or otherwise) to all or substantially all of the business, assets
or stock Supply to expressly assume the guarantee and to fulfill the obligations
hereunder as if no succession had taken place.

     4. Section 13(a) of the Employment Agreement is hereby deemed amended to
the extent necessary to give full effect to the assignment contemplated by
Section 3 of this Amendment and Assignment.

     5. Except as expressly amended above, the terms and conditions of the
Employment Agreement shall continue in full force and effect.

The foregoing Amendment and Assignment is hereby accepted and the terms and
conditions thereof hereby accepted and agreed to by the undersigned.

                                           ALLEGHENY ENERGY, INC.


                                           By:
                                              ----------------------------------
                                              Title:


                                           ALLEGHENY ENERGY SUPPLY LLC


                                           By:
                                              ----------------------------------
                                              Title:


                                           ALLEGHENY ENERGY SERVICE CORPORATION


                                           By:
                                              ----------------------------------
                                              Title:


                                           EXECUTIVE


                                           By:
                                              ----------------------------------

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