Exhibit 10.2 VASTAR RESOURCES, INC. FIRST AMENDMENT TO VASTAR RESOURCES, INC. STOCK OPTION PLAN FOR OUTSIDE DIRECTORS Pursuant to the power of amendment reserved therein, the Vastar Resources, Inc. Stock Option Plan for Outside Directors, effective June 26, 1994 (the "Plan"), is hereby amended as follows: 1. Section 2.8 is amended in its entirety and shall now read as follows: "Outside Director means a member of the Board who is not an employee of Vastar or its affiliates. For the purposes of this definition, an affiliate means any person or entity that, directly or indirectly, controls, or is controlled by, or is under common control with, Vastar." 2. Except as amended hereby, the Plan remains unchanged and in full force and effect. Executed as of the 1st day of December, 1999, but effective October 20, 1999. ATTEST: VASTAR RESOURCES, INC. /s/ JONATHAN D. EDELFELT /s/ JEFFREY M. BENDER By: --------------------------- By: ------------------------------- Jonathan D. Edelfelt Jeffrey M. Bender Associate Secretary Vice President, Human Resources