Wal-Mart Stores, the world's number one retailer, has reported a 3.3 per cent increase in September same-store sales and says it is sticking with its earnings guidance of 40 to 41 cents for the(third quarter, and $1.76 to $1.78 for the year. Net sales at all outlets grew 10.4 per cent year-on-year to $21.9 billion.