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                                                                   EXHIBIT 10.3


     AMENDMENT TO JOINT VENTURE AGREEMENT FOR ESSEX ROYALTY JOINT VENTURE II



         Amendment Agreement entered into as of August 21, 2000 by and between
Essex Royalty Limited Partnership II (Essex II) and Edge Petroleum Corporation,
formerly known as Edge Joint Venture II (Edge).

         Essex and Edge entered into a Joint Venture Agreement dated May 20,
1994 creating the Essex Royalty Joint Venture II (hereinafter the Agreement). In
consideration of the mutual covenants contained herein, the parties agree to
amend the Agreement, effective January 1, 2001, as follows:

         1. Article 7.1 of the Agreement shall be amended to substitute John
Sfondrini and Napamco, Ltd., a New York corporation, in lieu of Edge Joint
Venture Venture II, as the Managing Venturer.

         2. Article 7.8 of the Agreement is amended to add a subparagraph (vii)
reading as follows: "and (vii) independent contractors and third persons who
perform services for the Joint Venture."

         3. Article 7.8 (c) is amended by deleting the language in parenthesis
"(to be allocated to Edge Petroleum Corporation)."

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         4. The definition of Sharing Ratio Shift is amended to read as follows:
"that point in time whether such occurs during the Term hereof, or during the
Wind-Up Period, when the aggregate amount of (a) cash actually distributed to
the Limited Partnership during the year 2001 and subsequent years and/or (b)
Non-Operating Interests actually distributed to the Limited Partnership during
the year 2001 and subsequent years subject to the limitations of and valued as
set forth in paragraph 6.3 below, equals $3,324,587.

         5. Notwithstanding anything to the contrary in this Amendment
Agreement, it is understood that Edge is retaining its 25% interest after a
Sharing Ratio Shift as redefined in paragraph 4 above, to be allocated as
provided in Exhibit A to the Joint Venture Agreement. Where the Joint Venture
Agreement makes provision for distribution of 25% of the Managing Venture as in
paragraph 11.3, subject references shall continue to refer to the Edge.

         6. The parties have by their practice mutually extended the term and
wind up period of the Joint Venture. In order to avoid the need to sell the
various oil and gas interests of the Joint Venture, it is the intent of the
parties to further extend the windup period until there has been a Sharing Ratio
Shift as redefined above and then either (a) distribute and various oil and gas
properties 75% to the Essex Limited Partnership, 12.5% to Edge Petroleum
Corporation and 12.5% to Edge Group II Limited Partnership, Gulf Edge Limited
Partnership and Edge Group Partnership in accord with their respective
interests, or (b) continue to distribute the net revenues to the venturers in
accordance with their respective new Sharing Ratios.

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         In witness whereof the parties have signed this agreement, this 21st
day of August, 2000, effective January 1, 2001.


EDGE PETROLEUM CORPORATION

By:  /s/ John W. Elias
    ---------------------------------
    John W. Elias
    Chairman, President & CEO



ESSEX ROYALTY Limited Partnership
By: Napamco, Inc.
    John Sfondrini, General Partner

By:  /s/ John Sfondrini
    ---------------------------------
    John Sfondrini



NAPAMCO, LTD.

By:  /s/ John Sfondrini
    ---------------------------------
    John Sfondrini, President