But some industry analysts had expected a bigger decline as GM struggled to rebound from the summer strikes at two parts plants in Flint, Michigan that idled nearly all the automaker's North American production.

GM, the world's largest automaker, said sales of cars and light trucks fell 3.2 per cent to 391,118 units last month from 404,133 in the same period last year. Total vehicle sales, including heavy trucks, fell 3.1 per cent.

Despite GM's decline, total US automotive industry sales rose 6 per cent to 1,282,345 last month, up from 1,209,541. Sales of light trucks -- pickup trucks, sport utility vehicles and minivans -- were up 10.4 per cent, while car sales rose 2.4 per cent.

``What it boils down to is a very strong month for vehicle sales,'' Burnham Securities analyst DavidHealy said. ``Given GM's still-shallow inventory of cars and trucks, expired retail incentives and the US stock market gyrations, the performance was surprising, he added.

For GM executives, September was a step closer to normalcy. ``Our September sales show we can get back to pre-strike momentum, but we still have some catching up to do,'' a GM vice-president Roy Roberts, told reporters at the company's new downtown Detroit headquarters.

Ford, the No 2 US automaker, said sales of cars and light trucks rose 4.9 per cent to 324,456 units last month from 309,379 a year earlier. Total sales rose 4.1 per cent.

Ford's continued strength led the automaker to boost its fourth-quarter production by 20,000 vehicles to meet demand, vice- president Bob Rewey of marketing, sales and service, said in a statement.

``The results are quite encouraging,'' he said. ``The fundamentals that drive auto demand -- income growth along with low interest and unemployment rates -- remain favourable and consumer confidence isstill good.''

Leading the charge were Ford's light trucks, which set a September record with sales of 195,875 vehicles. Sales of the Explorer sport-utility vehicle surged 41 per cent, partly because of limited supplies of Chrysler's new Jeep Grand Cherokee, which just started reaching dealers last month, and GM models because of the strike, Ford spokesman George Pipas said.

Other strong sellers for Ford included the F-Series full-size pickup truck, up 18.5 per cent, the Ranger compact pickup, up 12.3 per cent, and the Mercury Mountaineer sport-utility, up 17.2 per cent.

Ford's Jaguar division's sales rose 20 per cent. Saab, half-owned by GM, rose 11.8 per cent and Germany's Porsche AG slipped 9.4 per cent. Last week, Chrysler Corp said its sales rose 18.2 per cent, while Toyota Motor Corp and Honda Motor Co Ltd said their sales rose 42.6 and 8.8 per cent, respectively. Nissan Motor Co Ltd said its sales slipped 13.6 per cent.

GM saw its monthly share of the US market slip to about 22 per cent in Julyand August from 31 per cent in the first half. Roberts said GM was near 30 per cent last month and wants to reach 31 per cent by year-end. ING Baring Furman Selz analyst Maryann Keller said taking market share away from competitors will be difficult.

``The deals are good today almost across the board,'' she said. ``So really it's going to be the product line that determines whether GM gets to 31 per cent and I'm not sure whether they can achieve that penetration level unless they crank out a lot of trucks.''

Roberts added that GM's inventories were at 80 per cent of pre-strike levels. It expects to make about 1.4 million cars and trucks in the fourth quarter, the most in a decade.

GM's chief forecaster, Mike DiGiovanni said fourth-quarter retail incentives will average $1,087 per 1999-model vehicle. GM's stock was down $2.31 at $52.69 and Ford was down $3 at $40 on the New York Stock Exchange in late trading.