WASHINGTON (MarketWatch) - U.S. retail sales posted the biggest increase in February in five months, but about half the increase took place at gas stations and reflected higher prices at the pump. Sales rose a seasonally adjusted 1.1% last month, or by 1.0% excluding the auto sector, the Commerce Department said Wednesday. Economists surveyed by MarketWatch expected retail sales to jump 0.7% for both the overall number and minus autos. Sales rose a smaller 0.6% excluding gas stations and 0.4% minus autos and gas. Retail sales are a good proxy for how fast the U.S. is growing and the latest data sugggest consumer spending is fairly steady. In the past 12 months, retail sales are up 4.6%, slightly more than double the rate of consumer inflation. Last month, sales surged at auto dealers, gas stations, building-material stores and Internet retailers. Gas-station sales shot up 5%, the biggest increase since oil prices spiked last August. Sales also rose slightly for stores that sell clothes and general merchandise. Sales fell at department stores and shops that sell home furnishings, electronics, and sporting and hobby items. Bar and restaurant sales also declined. In January, the increase in retail sales was revised up a tick to 0.2%. December sales were unchanged at a 0.5% gain.