Oil rose above $64 a barrel on Tuesday, after falling for four consecutive sessions on doubts over global economic recovery and potential improvement in demand for fuel.
U.S. light crude for August delivery rose 36 cents to $64.41 a barrel by 0924 GMT (5:24 a.m. EDT), having settled down 4 percent on Monday at $64.05, its lowest settlement in more than a month.
London Brent crude was up 45 cents at $64.50.
Expectations that renewed economic strength could support demand have helped lift crude prices off December lows below $33 a barrel. However, recent weak data -- including a bleak U.S. jobs report last week -- dampened sentiment, seeing oil prices fall seven percent in July.
Markets are re-pricing after an overly optimistic recent view on oil prices. Also, the stronger U.S. dollar has helped to push oil lower, said Carsten Fritsch, oil analyst at Commerzbank.
World stock markets have also slipped since the beginning of the month, while the U.S. dollar has strengthened, providing further signals that investors are questioning the pace at which global economy will improve.
Growing unrest in Nigeria, where militants have launched at least four attacks against oil installations in the past 10 days, helped to limit losses on Tuesday.
The main militant group said on Monday it had sabotaged a Chevron oil facility and seized a chemical tanker and six crew members.
The market could find more direction from the American Petroleum Institute's weekly crude and products stocks data to be released at 2030 GMT, expected to show a fall in crude and a rise in product inventories.
Analysts polled by Reuters predicted data will show U.S. crude oil inventories fell last week for the fifth week in a row by 2.2 million barrels on average, while they expected gasoline stocks to have gained 800,000 barrels and distillate inventories 1.7 million barrels.
The Energy Information Administration (EIA) will release its monthly report later on Tuesday. Last month, it raised its forecast for 2009 world demand by 10,000 barrels per day (bpd) to 83.68 million bpd, the first time since September that it had increased the demand estimate in its rolling monthly forecast.
(Editing by Anthony Barker)