Aug. 14 (Bloomberg) — Wal-Mart Stores Inc., the world's largest retailer, reported stagnant same-store sales and cut its earnings forecast for the year, hurt by higher health-care costs and slow traffic at its supercenters.

Earnings for the year will now be $4.90 to $5.15 a share, down from a previous range of as much as $5.45, the Bentonville, Arkansas-based company said today in a statement. Sales at U.S. Wal-Mart and Sam's Club stores open at least 12 months were little changed last quarter, which ended Aug. 1.

Chief Executive Officer Doug McMillon, who took the post in February, is trying to revive U.S. growth in the face of a slow economic recovery. The retailer hasn't posted a same-store sales gain for six quarters, and customers are making fewer trips to big-box retailers. Cuts in government assistance also are leaving low-income shoppers with less money to spend.