Oil prices fell more than 1 percent in early trading on Monday over doubts that an OPEC-led plan to cut output to rein in a global fuel supply overhang would be supported by other producers, including Russia.
International Brent crude oil futures were trading at $51.34 per barrel at 0001 GMT, down 0.59 cents, or 1.1 percent, from their last settlement.
U.S. West Texas Intermediate (WTI) crude futures were down 57 cents, or 1.1 percent, at $49.24 a barrel.
