Brent crude gave back early gains and turned lower Friday after a closely watched forecaster said world oil supply is adequate and the outlook for demand is weakening.
Meanwhile, U.S. crude pared gains but stayed in positive territory on a lift from Wall Street.
The monthly report by the International Energy Agency (IEA) on Friday weighed on crude markets. The IEA said the market looked "adequately supplied for now" and trimmed its forecasts for world oil demand growth this year and next.
"The weaker outlook has gotten a raised profile in the market, but there's potential for a real supply crunch toward the end of this year," said John Kilduff, a partner at Again Capital Management in New York. "The demand outlook is hurt right now because of the situation with the U.S. and China in particular."