New York's main contract, light sweet crude for delivery in November, shed 50 cents to $78.70 a barrel.

Brent North Sea crude for November delivery dipped 77 cents to $101.99.

Asian equities led crude markets down as traders flocked to the safe-haven US dollar amid pessimism on the global economy, said Victor Shum, senior principal of Purvin and Gertz energy consultants in Singapore.

"There is a selling in oil futures tracking equities and the strengthening of the US dollar," he told AFP.

"Global markets continue to be concerned about economic growth, especially in Europe and the US... Because of the concern about global markets, there is a flight to safety with investors flocking to the US dollar," Shum added.

Major Asian bourses were sharply down in early trade -- with Tokyo and Hong Kong stocks plunging 1.52 and 3.03 percent respectively -- as European debt fears resurfaced after Greece said it would miss its deficit target set for it by the IMF and EU.

The US dollar rose against the euro as traders forsook stock markets for the safe-haven currency, with the European unit trading at $1.3334 from $1.3451 in the US late Friday.

A strengthening greenback makes dollar-priced crude more expensive to traders using other currencies.