U.S. retail sales rose in February, the Commerce Department (search) said in a report on Thursday, but the gain was mostly confined to auto dealers and department stores, raising questions about one of the economy's most resilient sectors, consumer spending.

The department said retail sales rose 0.6 percent to a seasonally adjusted $327.17 billion in February, in line with Wall Street economists' expectations. But sales outside of autos were unexpectedly flat compared with January, defying economists' projections for a 0.5 percent gain.

However, January retail sales figures were revised up to a 0.2 percent increase, while sales excluding autos rose 1.2 percent. Previously, January sales had been reported down 0.3 percent overall and up a smaller 0.9 percent aside from autos.

Economists closely watch retail sales as major portion of consumer spending (search), which accounts for about two-thirds of total economic activity.

The 2.7 percent gain in February auto sales was the biggest advance since March 2003, while a 1.2 percent gain in department store purchases was the biggest since July.