NEW YORK — Wal-Mart Stores Inc. raised its full-year earnings forecast yesterday after second-quarter profit rose more than expected, helped by tight inventory controls and a renewed focus on low prices that is attracting financially squeezed shoppers around the world.

But the world's largest retailer predicted slower sales growth at its established stores in the U.S. for the current quarter, as the benefits of the federal stimulus checks dry up and customers find it more difficult to stretch their paycheck to the next payday.

Wal-Mart said it earned $3.45 billion in the quarter ended July 31, up 17 percent from $2.95 billion a year earlier. Profit from continuing operations rose 9.3 percent to $3.39 billion, while net sales gained 10 percent to $101.6 billion.

For the quarter, the discounter posted same-store sales growth of 4.5 percent, excluding fuel sales, compared to a 1.9 percent increase a year earlier. Same-store sales, or sales at stores opened at least a year, are considered a key indicator of a retailer's health.