1 EXHIBIT 4.2 AMENDMENT NO. 1 TO LETTER AGREEMENT REGARDING PARTICIPATION IN CARRIZO 2001 PROGRAM Carrizo Oil & Gas, Inc., a Texas corporation ("Carrizo"), Berea Associates, LLC, Berea Oil & Gas Corp., PAC Finance (USA) Inc., William R. Ziegler,...Letter Agreement Regarding Participation in Carrizo 2001 Program • August 14th, 2001 • Carrizo Oil & Gas Inc • Crude petroleum & natural gas
