U.S. retail sales dropped in March as spending at gasoline stations tumbled and consumer purchases were mixed elsewhere.

Retail and food service sales contracted by 0.4% to a seasonally adjusted $418.28 billion, the Commerce Department said Friday. The figure was up 2.8% from a year ago.

Economists surveyed by Dow Jones Newswires had expected a 0.1% decrease. Retail sales are a key component of consumer spending, which accounts for more than two-thirds of demand in the U.S. economy.

Spending at gasoline stations plunged by 2.2%, and drivers could see additional relief in the coming months. The average price of gas for the peak spring-summer driving season is expected to fall by about 6 cents from last year, the Energy Information Administration said.

In a positive sign, sales rose at restaurants, online retailers and furniture stores. That may be an indication consumers spent their discretionary income on items beyond just the necessities.

But sales excluding gasoline fell 0.2% for the month. Sales were also down at auto dealers, electronics, sporting goods and department stores.

Retail sales excluding gasoline, automobiles and building materials--a figure watched closely by economists who use it as a truer gauge of consumer behavior--was down 0.12% in March, the Commerce Department said.

Earlier this week, retailers posted tepid sales for the second straight month, after cold temperatures in March likely dragged down clothing sales and the weak job market held back confidence.

General merchandise stores posted a 1.2% decline in the Commerce report and department store sales were down 1.1%.

Friday's report showed that excluding autos, retail sales were down 0.4% in March after being up 1.0% the previous month.

March's fall in overall retail sales came after a revised 1.0% gain in February.