U.S. Department of Commerce on Wednesday upwardly revised the nation's economic growth rate to 1.7 percent in the second quarter this year, fresh evidence of the sub-par economic growth.

The level was quicker than the department's previous estimate of 1.5 percent last month, but lower than the 2 percent growth pace of the first quarter this year.

The deceleration of U.S. economic growth primarily reflected a slower pace of consumer spending, nonresidential fixed investment and residential fixed investment that were partly offset by a smaller decrease in federal government spending, an acceleration in exports and a smaller decrease in private inventory investment, the department said.

Consumer spending, which accounted for about 70 percent of the U.S. economy, grew by a 1.7 percent annual rate in the second quarter, compared with an increase of 2.4 percent in the previous quarter.

In the April-June period, motor vehicle output added 0.18 percentage point to the second-quarter change in real gross domestic product (GDP) after adding 0.72 percentage point to the first-quarter change.

Final sales of computers subtracted 0.09 percentage point from the second-quarter change in real GDP after adding 0.02 percentage point to the first-quarter change, said the department.

Real nonresidential fixed investment including industrial equipment and software rose 4.2 percent in the second quarter, compared with an increase of 7.5 percent in the first quarter. Real residential fixed investment rose 8.9 percent in the second quarter, compared with a rally of 20.5 percent in the first one, noted the report.

Real exports of goods and services increased 6 percent in the second quarter, quicker than the growth pace of 4.4 percent in the first one.

Real federal government consumption expenditures and gross investment decreased 0.1 percent in the second quarter, compared with a decline of 4.2 percent in the first quarter, added the department.

The change in real private inventories subtracted 0.23 percentage point from the second-quarter change in real GDP, after subtracting 0.39 percentage point from the first-quarter change.