FOURTH AMENDMENT TO CREDIT AGREEMENT BETWEEN THE EXPLORATION COMPANY OF DELAWARE, INC. TXCO ENERGY CORP. AND GUARANTY BANK, FSB AS LENDER Effective as of November 1, 2006 REVOLVING LINE OF CREDIT OF UP TO $50,000,000Credit Agreement • March 16th, 2007 • Exploration Co of Delaware Inc • Crude petroleum & natural gas • Texas
