EXHIBIT 7.3 FIRST AMENDMENT TO STOCKHOLDERS AGREEMENT This First Amendment to Stockholders Agreement ("First Amendment") dated effective as of July 29, 2005 is made by and among Energy Spectrum Partners, LP ("Energy Spectrum"), the Investors Group (as...Stockholders Agreement • August 26th, 2005 • Allis Chalmers Energy Inc. • Misc industrial & commercial machinery & equipment
Contract Type FiledAugust 26th, 2005 Company Industry