1 EXHIBIT 2.1 AMERADA HESS CORPORATION DAVID G. STEVENSON P. 0. BOX 2040 VICE PRESIDENT AND HOUSTON, TEXAS 77252-2040 ASSOCIATE GENERAL COUNSEL 713-609-4100 May 7, 1996 DLB Oil & Gas, Inc. 1601 N.W. Expressway Suite 700 Oklahoma City, Oklahoma 73118-1401 Attention: Mark Liddell Gentlemen: Reference for all purposes is herein made to that certain Agreement for Purchase and Sale dated April 16, 1996, between Amerada Hess Corporation ("Seller") and DLB Oil & Gas, Inc. ("Buyer") covering the sale of various oil and gas properties in Oklahoma ("Agreement"). Buyer has requested that the Closing Date under Section 11.1 of the Agreement be changed from June 14, 1996 to May 31, 1996. Seller is agreeable to this change, subject to the following conditions and amendments of the Agreement: 1. Buyer shall complete its title review under Article VII of the Agreement and notify Seller of any Title Defects by May 17, 1996. 2. Buyer shall complete its environmental assessment of the Assets as prescribed in Article XIV of the Agreement by May 17, 1996. If you are in agreement with the above, please execute a copy of this letter at the place designated below, whereupon this letter will be an amendment of the Agreement, binding upon both Seller and Buyer. Sincerely, AMERADA HESS CORPORATION By: /s/ D. G. Stevenson ------------------------------ D. G. Stevenson ACCEPTED AND AGREED TO THIS 8TH DAY OF MAY, 1996 DLB OIL & GAS, INC. By: /s/ Mark Liddell ------------------------------ Mark Liddell President