Oil and gasoline futures retreated Monday amid more signs of economic weakness in the United States.

On the New York Mercantile Exchange, the price for light sweet oil for December delivery fell $3.90 to $63.91 US per barrel, while gasoline was off almost eight cents a gallon at $1.3625 US.

The drop came after the Institute of Supply Management in the U.S. released its manufacturing index for September. The index came in at 38.9, the lowest figure since September 1982. A reading below 50 indicates a contraction in the manufacturing sectors.

Victor Shum, an analyst at Purvin & Getz in Singapore, said he expects continued "downward volatility" in oil prices, and he expects a near-term price range of $60 to $70 US.

He added that unemployment data due out later this week will reinforce the economic situation in the United States.

Other analysts are forecasting weak for energy in another major market, China.

Credit Suisse analyst Mark Flannery said he expects zero growth in oil demand in China next year. That is down from an earlier forecast of four per cent demand growth.

The weaker gasoline futures prices are translated into lower retail pump prices for motorists. Gasbuddy.com said the average price in Canada on Monday for a litre of regular unleaded gasoline was 99.046 cents a litre. That is down from 104.877 cents a litre one week ago, and 121.529 cents a month ago.