THE WOODLANDS, Texas (AP) — Chevron Phillips Chemical Company LLC said Tuesday that its chief operating officer will retire and will not be replaced.

Chevron Phillips Chemical said COO Timothy G. will retire Dec. 13 after 31 years with the company. Before becoming COO, he was executive vice president, olefins and polyolefins.

The company also announced that Mark Haney, current executive vice president, olefins and polyolefins, will retire Dec. 31. He has been with Chevron Phillips Chemical since 2000 and prior to that worked at Phillips Petroleum since 1977.

Haney will be replaced by Mark Lashier, who is currently senior vice president, specialties, aromatics and styrenics. Lashier will become executive vice president, olefins and polyolefins on Jan. 1.

Dan Coombs, currently vice president of corporate planning and development, will replace Lashier. Coombs will be replaced by Ron Corn, who is currently vice president, olefins and NGL.

Lashier, Coombs and Corn will report to Peter Cella, the company's president and CEO.

Chevron Phillips Chemical was formed in 2000 when Chevron Corp. and Phillips Petroleum Company, now ConocoPhillips, combined their worldwide petrochemical businesses.