Mumbai: A rise in consumer spending and strong export performance in the third quarter US powered economic growth rate to its fastest since the beginning of 2006, government data showed.

Gross domestic product in the US edged higher to 3.9 per cent, up from 3.8 per cent in the second quarter - the strongest quarterly growth since the 4.8 per cent growth recorded in the first quarter of 2006, the commerce department reported.

While surveys have shown that consumer confidence has suffered from a subprime mortgage crisis, consumer spending actually picked up to 3 per cent during the third quarter from 1.4 per cent in the second quarter.

US exports vaulted 16.2 per cent, more than double the second quarter''s 7.5 per cent - the strongest increase since the fourth quarter of 2003.

The Federal Open Market Committee, the policy-making members of the Federal Reserve will use the GDP data to gauge economic performance before announcing whether they will reduce interest rates.

The Fed is expected to trim its key federal funds rate a quarter percentage point but the strong GDP report may create some uncertainty in financial markets whether the extra tonic is needed.