The Commerce Department has left U.S. annual economic growth unchanged at 1.9 percent for the first quarter of 2012 in its third and final estimate released Thursday.

The modest rate -- initially estimated at 2.2 percent but revised down to 1.9 percent in the second estimate -- represents a deceleration from the 3 percent growth in the final quarter of last year.

The first-quarter slowdown primarily reflected decelerations in private inventory investment and in nonresidential fixed investment, which were partly offset by accelerations in personal consumption expenditure, and in residential fixed investment and a deceleration in imports, the Commerce Department said.

Consumer spending, which accounts for about 70 percent of the U.S. economy, grew by a 2.5 percent annual rate, slightly lower than the 2.7 percent uptick figure in the second estimate released last month, but higher than the 2.1 percent in the previous quarter.

Real nonresidential fixed investment increased 3.1 percent in the first quarter, significantly higher than the 1.9 percent in the second estimate.

Real exports of goods and services increased 4.2 percent, lower than the 7.2 percent in the second estimate. Real imports of goods and services increased 2.7 percent, much lower than the 6.1 percent rate in the second estimate.

Real federal government consumption expenditures and gross investment decreased 5.9 percent, unchanged from the second estimate.

The change in real private inventories added only 0.1 percentage point to the first-quarter change in real GDP, in sharp contrast with the 1.81 percentage points contribution in the fourth quarter of last year.

Some analysts worry that feeble job creation could dampen consumers' confidence and stop economic growth from accelerating. They don't expect much change in the second quarter.

The Federal Reserve has downgraded its forecast for the economy. It expected growth of 1.9 percent to 2.4 percent, about a half percentage point lower than its previous estimate in April. The Fed didn't expect the unemployment rate to fall much further for the rest of the year.