Exhibit 4(a) FOURTH AMENDMENT TO REVOLVING CREDIT AGREEMENT Amendment, dated as of April 17, 1998, among ANADARKO PETROLEUM CORPORATION, a Delaware corporation (the "Company"), the Banks named on the signature pages hereof (individually a "Bank" and...Revolving Credit Agreement • May 15th, 1998 • Anadarko Petroleum Corp • Crude petroleum & natural gas • New York
