Wal-Mart should see improvement in sales at its US discount stores in the fourth quarter as the company returns items to shelves and focuses anew on low prices, the company’s chief executive said yesterday. “I expect to see positive sales results in this fourth quarter,” Mike Duke said of the unit at the world’s largest retailer’s annual meeting with analysts and investors. The US unit has seen sales at stores open at least a year fall in each of the past five quarters. Wal-Mart has faced increased competition from cut-price stores that have attracted customers hit hardest by the recession. At the same time, customers feeling more secure have traded up to rivals. Wal-Mart has been hit by a poorly executed attempt to cut down on the products in its stores and a failed attempt to increase traffic with thousands of temporary price “rollbacks”.