The U.S. economy shrank at an annual rate of 0.5 percent in the third quarter this year, the worst showing since the third quarter of 2001, the Commerce Department said Tuesday citing revised data.

The decline in gross domestic product (GDP) was unchanged from an estimate made a month ago for the July-September period and followed a growth pace of 2.8 percent in the second quarter.

The decrease in real GDP primarily reflected negative contributions from personal consumption expenditures, residential fixed investment, and equipment and software that were partly offset by positive contributions from federal government spending, private inventory investment, exports, nonresidential structures, and state and local government spending, the department said while releasing a report on the data.

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

In the third quarter, consumer spending, which accounts for two-thirds of overall economic activity, dropped at an annual rate of 3.8 percent, in contrast to a 1.2-percent growth rate in the previous quarter.

Spending on housing projects plunged 16.0 percent, steeper than the 13.3-percent drop in the second quarter, marking the 11th consecutive quarterly decline.

Spending by businesses on equipment and software declined 7.5 percent, worse than the 5.0-percent drop in the previous quarter.

Exports of goods and services rose by 3.0 percent after having jumped 12.3 percent in the second quarter, while imports of goods and services decreased 3.5 percent after having declined 7.3 percent in the second quarter.

Federal government spending in the third quarter, however, rose at a rate of 5.8 percent, stronger than the 3.9-percent growth pace in the previous quarter.

"Core" prices, which exclude volatile energy and food prices and are an inflation gauge closely watched by the Federal Reserve, rose at a rate of 2.4 percent in the third quarter, up from a 2.2-percent growth pace in the previous quarter.

GDP measures the value of all goods and services produced within a country. Many analysts fear the third-quarter contraction in GDP will be followed by much larger decreases this quarter and the next.

Editor: Yan