WASHINGTON (AFX) - The US economy contracted at a 1.1 pct annual rate in the third quarter, a slower pace than the previous estimate of a 0.4 pct downturn, the Commerce Department said. This is the largest quarterly decline in GDP growth since the first quarter of 1991. The downward revision was more than expected. The consensus forecast of Wall Street economists was for Q3 GDP to be revised down to show a 0.9 pct decline. The economy expanded at a 0.3 pct rate in the second quarter. The downward revision reflected a larger drawdown of inventories and a weaker trade sector than originally estimated. It does not substantially change the overall picture of the economy in the July-September quarter where weak business investment dragged GDP into its first negative quarter in eight years. The department did not attempt to quantify the total impact of the Sept 11 terrorist attacks on GDP because of the difficultly in isolating the impact of the attacks from the general economic weakness in the third quarter. Inventories fell a revised 60.1 bln usd in the third quarter, compared with the initial estimate of a reduction of 50.4 bln, marking a record fall in inventories. As a result, the change in inventories subtracted 0.75 percentage points from GDP growth, down from the initial estimate that inventories subtracted 0.37 percentage points from growth. This is the largest drawdown in inventories since the first quarter of 1983. Final sales - GDP growth minus inventory behavior -- fell a revised 0.3 pct in the third quarter, down from the previous estimate that final sales remained unchanged. The trade sector was more of a drag on third quarter growth than originally estimated as exports were revised down and imports were revised up, the department said. The trade sector subtracted 0.16 percentage points from Q3 GDP growth, more than the initial estimate that trade added 0.32 percentage points to growth. Exports fell at a revised 17.7 pct rate in the third quarter, sharper than the initial estimate of a 16.6 pct fall. Imports fell at a revised 12.9 pct rate in the third quarter, up from the initial estimate of a 15.2 pct decline. The GDP chain-weighted price index rose a revised 2.2 pct in the third quarter, compared with the initial estimate of a 2.1 pct rise. Excluding food and energy prices, the GDP chain-weighted index rose a revised 2.7 pct, up from the previous estimate of a 2.6 pct rise. The consumption price index fell a revised 0.3 pct in the third quarter, up slightly from the previous estimate of a 0.4 pct decline. Excluding food and energy prices, the consumption index was up 0.4 pct, up from the initial estimate of a 0.3 pct rise. Consumer spending rose at a revised 1.1 pct annual rate in the third quarter, down slightly from the initial estimate of a 1.2 pct gain. This is the slowest pace of consumer spending since the first quarter of 1993. The bulk of the downward revision to consumer spending came from lower spending on durable goods. Business investment fell at a revised 9.3 pct annual rate in the third quarter, up from than the initial estimate of a 11.9 pct drop. Software purchases fell at a revised 9.3 pct rate, stronger than the initial estimate of a 11.8 pct fall. Government spending was weaker than first thought, spending rose a revised 0.8 pct rate in the third quarter, slower than the initial estimate of a 1.8 pct gain. This is the first revision to Q2 GDP data. A second and final revision will be released on Dec 21.