NEW YORK - Wal-Mart U.S. chief Bill Simon is stepping down after being in the role since June 2010, the company said Thursday.

The world's largest retailer named the head of its Asian business as his replacement.

The Bentonville, Arkansas-based retailer said Greg Foran, 53, who was promoted to president and CEO of Wal-Mart Asia earlier this year, will succeed Simon. The changes will take effect Aug. 9. Wal-Mart Stores Inc. said Simon will be available on a consulting basis for the next six months to ensure a seamless transition.

U.S. Wal-Mart stores have suffered five straight quarters of sales declines at stores open at least a year, hurting from a tough economy and fierce competition from dollar stores and Amazon.com. The measure is considered a key indicator of a retailer's health because it excludes results from stores recently opened or closed.

Thursday's announcement marks the company's biggest management shakeup since Doug McMillon took over as president and CEO of Wal-Mart Stores Inc. in February.

Foran will report to McMillon, who had been head of Wal-Mart's international business before taking over the top job at the company.

Simon, who joined Wal-Mart in 2006, was the chief operating officer for Wal-Mart's U.S. division from 2007 to 2010 and created and launched Wal-Mart's successful $4 prescription drug program.

When Simon took over as CEO of Wal-Mart's U.S. division, he led the turnaround of Wal-Mart's business right after the recession by focusing on the company's roots of offering everyday low prices. He also helped restore thousands of popular items that the company had stopped selling in an overzealous attempt to declutter the stores. That helped Wal-Mart get out of a two-year slump in late 2011.

Simon also led the company's campaign to revitalize U.S. manufacturing and helped to spearhead the company's move to accelerate its plans for small-store formats. But Wal-Mart, like many of its store rivals, is facing seismic changes in the retail landscape as shoppers are increasingly going to small stores or buying and researching on their mobile devices for convenience.

The move to name Foran indicates Wal-Mart is looking to further shake up its strategy.

"Greg is one of the most talented retailers I've ever met," McMillon said in a statement. "His depth of knowledge and global experience will bring a fresh perspective to our business. His passion for fresh food, experience in general merchandise and commitment to e-commerce will help us serve our customers even more effectively for years to come."

Foran, a 35-year retail industry veteran, joined Wal-Mart in October 2011 and became president and CEO of Wal-Mart China in March 2012. He was promoted to president and CEO of Wal-Mart Asia earlier this year.

Before joining Wal-Mart, Foran held a number of roles with Woolworths, the leading retailer in Australia and New Zealand.