The economy grew much slower than originally thought at the end of 2010, according to new estimates released by the government Friday.

Gross domestic product, the broadest measure of economic activity, was revised sharply lower to an annual growth rate of 2.8 percent in the three months ending in December. The initial reading had been for a 3.2 percent growth rate in the period.

That’s a surprising dip, given that economists were expecting the rate to be revised upward to 3.3 percent.

The revision came as consumers spent less than originally expected, and the country imported more goods than in the initial report. Less state and local government spending also lowered the rate.

The government calculates GDP as a measure of goods and services produced in the United States. The number is backward looking and is often revised multiple times. This is the second reading for the fourth quarter.