The US government has lifted its estimate of economic growth in the first three months of 2006 to an annualised rate of 5.6%.
The Commerce Department said the figure - up from the 5.3% reported a month ago - was helped by lower imports than first thought and stronger company profits.
The latest figure slightly exceeded Wall Street economists' predictions for a 5.5% rate and meant the economy expanded at more than triple the 1.7% pace recorded in last year's fourth quarter. It was the strongest quarterly growth since the third quarter of 2003.
The pace of economic growth is expected to moderate in coming quarters, partly because of some softening in the housing sector that analysts say will potentially have an impact on consumer spending, the key driver of US economic performance.
Consumer spending in the first quarter advanced at a revised 5.1% rate rather than 5.2% estimated a month ago, but still far ahead of the 0.9% rate recorded in the fourth quarter of 2005.
The department said its main reason for revising first-quarter GDP upward was that imports were not as strong as it previously had calculated. Imports, which act as a drag on overall GDP, rose at a 10.7% annual rate in the first quarter rather than 12.8%.
Corporate profits also grew more strongly than the government previously thought, rising at a 13.8% annual rate after taxes instead of the 8.8% it estimated a month ago.
There was little or no change in the data on prices, which remained in check. The core personal consumption expenditures price index, which the Federal Reserve watches closely, rose at a 2% rate, the same as estimated a month ago, compared with 2.4% in the fourth quarter.
