Investing.com - Oil Wednesday extended losses as investors questioned the potential impact of OPEC's output cut on a persistent supply overhang.
U.S. crude fell 29 cents, or 0.57%, to $50.64 at 07:45 ET. Brent crude lost 0.63% to $53.59.
OPEC last week agreed to cut output by 1.2 million barrels a day to 32.5 million.
However, both OPEC and Russia posted record output in November.
OPEC and non-OPEC producers are due to meet this weekend to discuss a proposed cut of 600,000 barrels a day by the latter.
The International Energy Agency said Tuesday said if the cuts are implemented they should speed up the rebalancing of the market next year.
American Petroleum Institute weekly data Tuesday showed a fall in U.S. crude stocks of 2.2 million barrels.
Official Energy Information Administration figures due out Wednesday are forecast to show a fall of 1.032 million barrels.