Suncor Energy Inc. (NYSE: SU) said Nov. 14 its CEO will retire mid-next year, with the company's COO taking over the top job at that time.

Steve Williams, who has been with the company for 16 years and CEO since 2012, will step down after Suncor's Annual General Meeting in May 2019, the Calgary, Alberta-based company said.

He will be replaced by COO Mark Little, who was also named company president, effective immediately, Suncor said. Little joined the company in 2008 and was appointed COO last year.

"I’m confident in Mark’s ability to lead the company going forward," said Williams in a statement. "He has significant experience, business acumen, passion and energy which will serve him and Suncor well."

Suncor is Canada's second-largest energy producer, with a diversified portfolio of oil sand operations and refineries.