WASHINGTON -- Americans stepped up their spending at retail businesses in September.

Retail sales rose 1.1% last month, the Commerce Department said Monday. That followed a 1.2% increase in August, which was revised slightly higher.

Both were the largest gains since October 2010.

A second report Monday said companies restocked their shelves at a solid pace in August.

The combination of higher stockpiles and increased sales should help boost economic growth.

Business inventories grew 0.6% in August following a July gain of 0.8% that had been the strongest since January, the Commerce Department said. Companies typically boost their stockpiles when they anticipate sales will rise in coming months. Faster restocking helps drive economic growth. When businesses order more goods, it typically leads to more factory production.

Total business stockpiles rose to $1.60 trillion. That is 22.4% higher than the low in September 2009. For August, inventories rose 0.6% at the manufacturing and retail levels and were up 0.5% at wholesale businesses.

Excluding autos and gas, retail sales were still up a solid 0.9% in September.

One area of weakness was department store sales, which fell 0.2% after no change in August.

The retail sales report is closely watched because it is the government's first look at consumer spending each month. Consumer spending drives nearly 70% of economic activity. High unemployment and weak pay increases have kept consumers from spending freely. That has held back growth.

The economy grew at a weak 1.3% rate in the April-June quarter. Most economists believe growth will stay around 2% for the rest of the year.

Despite the weak growth, consumers grew more confident in September. The Conference Board reported its confidence index rose last month to the highest reading since February.

The job market also looked a little better in September. The unemployment rate dropped to 7.8% from 8.1% in August. It was the first time the rate has been below 8% since January 2009.

And U.S. auto companies reported that sales rose 13% in September from a year earlier to nearly 1.2 million. Analysts think sales could hit 14.3 million this year, up from 12.8 million last year. The Federal Reserves' aggressive policies have kept interest rates low, encouraging some Americans to replace aging vehicles.

Associated Press