EXECUTION COPY AGREEMENT, dated April 13, 2005, between Kerr-McGee Corporation, a Delaware corporation (the "COMPANY"), the parties listed on the signature pages of this agreement as Icahn Parties (each, an "ICAHN PARTY" and, collectively, the "ICAHN...Execution Copy • April 14th, 2005 • Jana Partners LLC • Crude petroleum & natural gas • New York
