Investing.com - Oil was mostly flat Thursday as concerns about a supply glut wiped out earlier gains amid disruption to Libyan output.
U.S. crude was unchanged at $49.51 at 08:00 ET. Brent crude shed 10 cents, or 0.19%, to $52.44.
The Energy Information Administration reported a lower than expected rise in U.S. crude inventories.
Stockpiles still remain at record highs of 534 million barrels. Gasoline stockpiles fell more than expected.
Higher U.S. supply and inventories continue to weigh on the market.
That is undermining the impact of production cuts by major producers.
OPEC and non-OPEC producers are cutting output by 1.8 million barrels a day in the first half.
There are expectations the cuts could be extended beyond June.