The U.S. economy grew more than expected in the last three months of 2009, growing at a better than expected annual rate of 5.7 percent in the fourth quarter, the U.S. government reported today.

Revisions of today's advance estimate are due in February and March as more complete data become available, the U.S. Commerce Department noted.

Initial third quarter estimates of 3.5 percent growth released last October also beat expectations. They were revised downward to 2.2 percent in the subsequent months.

Today's results beat a median estimate of 4.7 percent, according to a poll of 84 economists in a Bloomberg survey. Estimates ranged from 3 percent to 7.5 percent.

Growth in GDP primarily came from three areas:

- Growth of finished and unfinished products being stored in warehouses across the country, known as private inventory investment

- Exported products

- Consumer spending, known as personal consumption expenditure

Acceleration in GDP growth came from:

- Acceleration in private inventory investment

- Deceleration of imports

- An upturn in nonresidential fixed investment, which measures business investment in nonresidential structures and equipment and software.

Investment