Wal-Mart ( WMT) Saturday said sales rose 2.4% in July at stores that have been open for at least a year.The increase was toward the upper end of the retailer's forecast for a 1% to 3% gain. It follows a disappointing 1.2% rise in June. Some on Wall Street were expecting another lackluster figure in July after rival Target ( TGT) lowered its monthly forecast two weeks ago. Wal-Mart, however, encouraged consumers to visit its stores last month by starting its back-to-school promotional campaign earlier than usual. Retail watchers remain concerned that high gas prices and rising interest rates are taking a toll on consumer spending. Wal-Mart plans to report final July sales results on Thursday, when most other large retailers plan to do so. Wal-Mart shares ended Friday up 93 cents at $44.46. Target finished the session up 37 cents at $46.46.