Oil prices turned lower in volatile Asian trade on Friday after US crude stockpiles surged, with investors keeping an eye out for further clues on the health of the US economy.
New York's West Texas Intermediate for June delivery was down three cents to $99.39 a barrel in afternoon trade, and Brent North Sea crude for June dipped six cents to $107.70.
Both contracts had been up in mid-morning trade.
Prices eased on Thursday after the US Department of Energy's weekly estimate of crude oil stockpiles showed a gain of 1.7 million barrels to 339.4 million -- the highest weekly level since 1982 -- indicating weaker demand in the world's largest economy.
That came a day after official data showed the US economy grew just 0.1 percent year-on-year in the first three months of 2014, much slower than the 2.6 percent in the previous quarter and well short of forecasts.
However, research house Capital Economics noted that the US Federal Reserve's statement on the economy "takes a more upbeat tone than the one issued after the last meeting in mid-March". Wednesday's statement said the economy had "picked up" after a bout of fierce winter weather.
Traders were awaiting fresh jobs figures due out in Washington later on Friday for further signs of a US recovery.
It was hoped the non-farm payrolls figures would show a pick-up after flattening at the start of the year because of the weather.
Prices got some support in Asia after the release of figures showing manufacturing in both China and the United States picked up in April.
Washington also said consumer spending in the United States rose at its fastest pace in almost five years in March.
