Investing.com - Oil was mixed Monday on concerns increased U.S. supply could curtail the positive impact of output cuts agreed by other producers.
Brent crude was off 4 cents, or 0.07%, at $55.66 at 08:00 ET. U.S. crude added 6 cents, or 0.11%, to $53.23.
Baker Hughes weekly data Friday showed an increase in the number of rigs operating in the U.S. of 15 to 556.
That was the highest level since November 2015.
OPEC and non-OPEC producers have agreed to cut output by some 1.8 million barrels a day in the first half of this year.