WASHINGTON – The U.S. economy grew at a 2.7 percent annual rate from July through September, much faster than first thought. The strength is expected to fade in the final months of the year because of uncertainty about looming tax increases and government spending cuts.

The Commerce Department said Thursday that growth in the third quarter was significantly better than the 2 percent rate estimated a month ago. And it was more than twice the 1.3 percent rate reported for the April-June quarter.

The main reason for the upward revision to the gross domestic product was businesses restocked at a faster pace than previously estimated. That offset weaker consumer spending growth.