Wal-Mart ( WMT) reiterated its previous guidance for July same-store sales Monday, saying inflation helped sales in certain categories. The gain in same-store sales is tracking in the 2% to 4% range, the company said on a recorded call. As it said last week, July's results are up against a difficult comparison because of last year's tax stimulus program. U.S. same-store sales in July 2003 increased 4.6%. Sales for the week ended July 16 were strongest in Wal-Mart's food and paper goods units, due primarily to inflation. Pet supplies were a strong category as well. The company also cited solid demand in its back-to-school segment. The Southeast and Midwest were the strongest regions in the week. Traffic and average ticket were positive, the company said, with ticketing making up the majority of the same-store sales increase. Same-store sales results for the period ended July 30 will be released on Aug. 5. Shares of Bentonville, Ark.-based Wal-Mart were down 15 cents, or 0.3%, at $52.50 in premarket trading.