EX-99.1 3 ex99_1.txt JOINT FILING AGREEMENT CUSIP No.25179M103 Exhibit 1 JOINT FILING AGREEMENT Kerr-McGee Corporation, a Delaware corporation, Kerr-McGee Worldwide Corporation, a Delaware corporation, Kerr-McGee Oil & Gas Corporation, a Delaware corporation, and Kerr-McGee Chemical Worldwide LLC, a Delaware limited liability company, each hereby agrees, in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, that the Schedule 13G filed herewith, and any amendments thereto, relating to the shares of common stock, par value $0.10, of Devon Energy Corporation is, and will be, jointly filed on behalf of each such person and further agree that this Joint Filing Agreement be included as an exhibit to such joint filings. In evidence thereof, the undersigned hereby execute this Agreement as of the date set forth below. Dated: January 3, 2003 KERR-MCGEE CORPORATION By: /s/ John F. Reichenberger -------------------------------- Name: John F. Reichenberger Title: Vice President, Assistant Secretary and Deputy General Counsel KERR-MCGEE WORLDWIDE CORPORATION By: /s/ John F. Reichenberger -------------------------------- Name: John F. Reichenberger Title: Vice President and Assistant Secretary KERR-MCGEE OIL & GAS CORPORATION By: /s/ John F. Reichenberger -------------------------------- Name: John F. Reichenberger Title: Vice President KERR-MCGEE CHEMICAL WORLDWIDE LLC By: /s/ John F. Reichenberger -------------------------------- Name: John F. Reichenberger Title: Vice President and Assistant Secretary