Global oil prices edged lower on Wednesday in cautious trading before publication of the latest inventories report in the United States.
Brent North Sea crude for delivery in June dropped 54 cents to $103.86 per barrel in London early afternoon deals.
New York's main contract, light sweet crude for June dipped three cents to $95.59 a barrel.
Crude futures had pulled lower on Tuesday as dealers booked profits from three straight days of gains amid expectations of another rise in US crude supplies.
"Crude oil prices retreated on Wednesday, as investors ... remain cautious ahead of the release of the US crude oil inventories report," said analyst Myrto Sokou at London-based brokerage Sucden Financial.
The report, issued by the US government's Energy Information Administration (EIA), is a vital focus for traders because the United States is the world's biggest economy and its largest oil-consuming nation.
"Due to the absence of major macroeconomic indicators, the release of the weekly EIA oil inventories report will set the tone in today's trading session," added Sokou.
"In the meantime, we expect further consolidation and some profit taking in the oil market."
Analysts polled by Dow Jones Newswires projected an increase of 1.4 million barrels in the week ended May 3. That would indicate falling American demand for oil.
Last week the EIA reported that US crude supplies hit their highest level since 1982, when the weekly report began, indicating that production was outstripping demand and putting downward pressure on prices.
Across in Asia, news of a record trade surplus for China helped to allay concerns about faltering demand in the world's second largest economy and biggest energy user.
China swung back to a trade surplus of $18.2 billion in April after posting a rare deficit the previous month, official data showed Wednesday.
April imports increased 16.8 percent year-on-year to $168.9 billion, Customs said, while exports rose 14.7 percent to $187.1 billion. In March, the country had posted a deficit of $880 million.
"The general consensus is that the Chinese trade surplus in April points towards stronger demand, despite some scepticism about its accuracy," Kelly Teoh, market strategist at IG Markets Singapore, told AFP.