AlQa'dah 29, 1433, Oct 15, 2012, SPA -- U.S. consumers increased their spending at retail businesses in September, reflecting higher consumer confidence, a government report showed on Monday. Retail sales rose 1.1 percent last month to $412.9 billion, the Commerce Department said. The rise followed a 1.2 percent increase in August, which was revised slightly higher. Both were the largest gains since October 2010. Sales rose last month in most major categories. Electronics and appliances surged 4.5 percent, in part because of iPhone sales. Sales at auto dealers increased 1.3 percent. Building materials and garden supplies, furniture, and clothing sales also gained. Economists said the September gains should help drive stronger growth in the July-September quarter. But some economists cautioned that the jump was driven by iPhone sales and the gain may be reversed in coming months. Some of the increase was driven by higher prices. Gas station sales also rose 2.5 percent, while food sales increased 1.2 percent. Excluding autos and gas, sales were up a solid 0.9 percent in September. The retail sales report is closely watched because it is the government's first monthly look at consumer spending, which drives nearly 70 percent of economic activity.