However, many analysts worry that exports and consumer spending, which have buoyed the economy, are likely to taper off in the second half of the year as government-support spending dries up and weakening global growth and a stronger US dollar crimp demand from abroad.

“This number seems to overstate the underlying strength even though exports are obviously strong,” said James O'Sullivan, an economist at UBS Securities in Stamford, Connecticut.

Consumer spending, which fuels two-thirds of the US economy, grew at an upwardly revised 1.7 per cent rate in the second quarter rather than the 1.5 per cent pace first reported.

Meanwhile, exports grew at a 13.2 per cent annual rate instead of the 9.2 per cent pace initially estimated. In all, a narrowing trade gap contributed more than 3 per centage points to GDP growth. Housing, however, continued to be a sore spot. Residential construction fell at an annual 15.7 per cent pace, slightly more than the 15.6 per cent decline reported earlier.