Chevron Corporation said that Raymond I. Wilcox, president of Chevron North America Exploration and Production Co., will retire from the company on March 31, 2006, to become president and chief executive officer of Chevron Phillips Chemical Company LLC, a company owned equally by Chevron and ConocoPhillips. Wilcox will be succeeded by Gary P. Luquette, currently managing director of the European strategic business unit of Chevron International Exploration and Production Co., effective April 1, 2006.