Oil dipped below $73 in choppy trade on Wednesday after OPEC trimmed its 2010 global demand growth forecast and as the dollar strengthened against the euro.
U.S. crude futures were trading at $72.91 a barrel, 84 cents down, after earlier hitting $74.30.
ICE Brent crude futures fell $1.11 to $71.01.
The Organization of the Petroleum Exporting Countries, the source of more than a third of the world's oil supply, said the slow pace of world economic recovery would put pressure on oil consumption.
OPEC said there had been a further rise in production by the group's 11 members subject to oil output limits. They pumped 26.80 million bpd of crude oil in January, up by around 150,000 bpd from December.
There have not been positive signs recently and OPEC is looking at that more, Eugen Weinberg, analyst at Commerzbank in Frankfurt, said on Wednesday.
The report shows supply has increased over the last weeks from OPEC and from the fundamental point of view it is difficult to see a positive picture for the oil market.
The euro fell against the U.S. dollar on Wednesday, surrendering early gains on uncertainty over the outcome of Thursday's European Union summit on a possible bailout of debt-strapped Greece.
Federal Reserve Chairman Ben Bernanke saying the U.S. central bank expects to increase the spread between the discount rate and the target fed funds rate before long further boosted the dollar and pushed the euro below the key $1.3700 level.
Dollar strength makes dollar-priced commodities more expensive for holders of other currencies.
Oil came under further pressure from a large increase in crude inventories in the United States and a fall in Chinese crude imports.
Chinese crude imports slid in January, to 4.03 million barrels per day from their December peak of 5 million bpd, although they were still up 33 percent on the year.
Crude stocks in the United States, the world's largest oil consumer, increased by 7.2 million barrels to 337.6 million barrels in the week to February 5, industry group American Petroleum Institute (API) said late on Tuesday.
The increase in crude inventories exceeded analysts' expectations for a 1.5 million barrel rise.
The release of official data from the U.S. Energy Information Administration (EIA) has been delayed to Friday from Wednesday because government offices were closed due to a snow storm.
The snow storm, the second major one in less than a week, lashed the East Coast from Washington to New York on Wednesday, forcing federal and local government agencies, the United Nations and schools to close.
(Additional reporting by Joe Brock in London and Jennifer Tan in Singapore; Editing by Amanda Cooper and Sue Thomas)