Oil prices have slumped back below US$71 a barrel as a stronger dollar overshadowed expectations of a sizable OPEC output cut and led investors to shed commodities bought as an inflation hedge, AP reported.
Light, sweet crude for November delivery fell US$3.36 to settle at US$70.89 on the New York Mercantile Exchange.
Crude oil is down 52 percent from its all-time peak of US$147.27 reached July 11.
In London, December Brent crude fell US$2.31 to settle at US$69.72 a barrel on the ICE Futures exchange.
In other Nymex trading, heating oil futures fell 3.24 cents to settle at US$2.1975 a gallon, while gasoline prices lost 2.82 cents to settle at US$1.6919 a gallon. Natural gas for December delivery rose 10.1 cents to settle at US$7.312 per 1,000 cubic feet.