Costco Wholesale announced that CEO Jim Sinegal will step down at the beginning of 2012. Sinegal said he will leave the company on Jan. 1, 2012, the same day he turns 76. Sinegal will be succeeded by Craid Jelinek, who currently serves as Costco's president and COO.

Sinegal will remain with Costco through January 2013 in an advisory role to assist in the transition and will continue to serve on the company's board of directors.

“Costco has a very strong culture and a deep bench of management talent,” Sinegal said in a statement. “I have total confidence in Craig's ability to handle his new responsibilities and feel we are fortunate as a Company to have an executive of his caliber to succeed me as Chief Executive of Costco.”

Jelinek has been with Costco for nearly 28 years, serving in every major role related to Costco's business operations and merchandising activities, the company said.

Costco also released same-store sales data for August, reporting that revenue from stores open for at least a year rose 11 percent last month. Costco said total revenue for the four weeks ended Aug. 28 was $6.9 billion, up of 17 percent from August 2010.