The U.S. economy grew at a 3.1 percent annual rate in the third quarter, more than previously reported, reflecting the first gain in state and local government spending in three years, more consumer purchases and a smaller trade gap.

The revised gross domestic product reading exceeded the highest projection in a Bloomberg survey and compared with a previously estimated 2.7 percent gain, according to Commerce Department figures released today in Washington. The median estimate of economists called for a 2.8 percent advance.

The world's largest economy will be hard-pressed to maintain that pace of growth this quarter as global demand cools and companies limit spending and hiring ahead of looming tax increases and spending cuts. While a stronger housing market will provide some cushion, the Federal Reserve is pursuing record stimulus aimed at driving bigger gains for the expansion.