Bentonville, Ark. -- Wal-Mart Stores announced that Bill Simon, president and CEO of Walmart U.S. since June 2010, is leaving the company. He will be replaced by Greg Foran, 53, president and CEO of Walmart Asia, who will take up the post on Aug. 9, reporting directly Wal-Mart president and CEO, Doug McMillon. Simon will be available on a consulting basis for the next six months to ensure a seamless transition.