US car and truck sales slowed down in October from strong levels in September, with Detroit manufacturers hit hardest by the slowdown in sales, according to reports.

Purchasing incentives contributing to strong sales during the last week of September probably accentuated the gloom of a poor October, while rising energy prices and falling consumer confidence also hampered results, according to analysts and industry officials.

"We're seeing a little bit of a payback in October, but sales are OK," commented Paul Ballew, General Motors' executive director of global market and industry analysis.

The average price of a gallon of gasoline reached $2.02 (£1.10) on Tuesday, within touching distance of the record $2.05 (£1.12) in May and up from $1.89 (£1.03) a gallon a month ago, according to the AAA motorist group's daily survey.

Nevertheless, Mr Ballew played down the effect of gas prices on new car and truck sales. "We're still trying to find the impact on the margins," he said. "It certainly is a drag on the economy."

Mr Ballew told Reuters he expects industry sales for October to hover around last year's levels at an annual rate of about 16.6 million to 16.7 million units, well down from September's 17.5 million rate.