WASHINGTON, Feb. 27 (Xinhua) -- The U.S. economy shrank at an annual rate of 6.2 percent in the final quarter of last year, much steeper than the 3.8 percent drop originally estimated and the 0.5 percent decline in the third quarter, the Commerce Department reported Friday.

It also was a considerablyweakerperformance than the 5.4 percent annualized decline economists had expected.

"The decrease in real GDP in the fourth quarter primarily reflected negativecontributions from exports, personal consumption expenditures, equipment and software, and residential fixed investment that were partly offset by a positivecontribution from federal government spending," the department said while releasing the report.

"Imports, which are a subtraction in the calculation of GDP, decreased," it added.

The largest contributors to the fourth-quarter drop were a downturn in exports and a big decrease in equipment and software, according to the department.

The most notableoffset was a plunge in imports.