Oil has dipped below $62 a barrel, ending four days of gains, as uncertainty over the outlook for energy demand persists.
"I think we could see the market below $60 again next week," said an oil dealer in London.
US crude fell 14 cents in morning trading to $61.88, while Brent crude was down 30 cents at $63.45.
Oil prices have tumbled nearly $10 since early July, partly reversing last quarter's 40% surge.
Figures released on Thursday showed a big increase in US gasoline stockpiles last week. This was despite the 4 July Independence Day holiday, when the summer driving season typically peaks.
The US remains the world's largest energy consumer.
