Oil held losses near $55 a barrel as USA crude stockpiles unexpectedly rose and production extended its record run.
The second consecutive week of rising stockpiles highlighted concerns that as oil has rallied, US shale producers have increased output to take advantage of the higher prices. The American Petroleum Institute on Tuesday had reported a 6.5 million-barrel climb, according to sources.
West Texas Intermediate for December delivery was at $55.40 a barrel on the New York Mercantile Exchange, up 7 cents as of 7:45 a.m.in London.
"After all, the need to further extend the agreement shows that the strategy is not working", commodity researchers at Commerzbank said, adding that the "key factor" was rising US shale oil output. "It's not a surprise to anybody, but it is a reality".
The recent gains recorded by global oil prices have slipped as the commodity has lost more than $2 in seven days.
As prices rise, "that can only encourage more and more USA production coming on board", said Tariq Zahir, managing member of Tyche Capital Advisors.
Gasoline supplies added 894,000 barrels, after three weeks of declines, but were contrary to expectations of a 919,000 barrel-loss.More news: Gigi Hadid Drops Out of the 2017 Victoria's Secret Fashion Show
More news: Federal judge declares mistrial in Menendez's corruption case
More news: Soccer earns seventh seed in NCAA tournament
A meeting of the Organization of the Petroleum Exporting Countries in Vienna on November 30 is expected to extend a production pact in an effort to tighten supply.
The deal participants are set to convene in Vienna on November 30 to assess the progress of the deal and debate the possibility of an extension.
The uptick in United States crude production added to recent fears that USA producers are set to ramp up output after the IEA said on Tuesday that it expected global crude markets to remain oversupplied through the second quarter of 2018 amid an uptick in U.S. production.
OPEC and other big exporters including Russian Federation agreed a year ago to cut crude output by 1.8 million barrels per day (bpd) between January this year and March 2018 to try to bolster prices. The agency now expects demand to grow by 1.5 million barrels a day this year and 1.3 million barrels a day next year.
The data also showed distillate stocks in the U.S. Gulf fell to a one-year low, while overall refining rates rose in the latest week, led by a jump in East Coast refining, which is operating at a record 99.8 per cent of capacity. USA light crude hit a three-day high, rising more than $1 before easing back to $56.03, 89 cents up on the day.
-Christopher Alessi contributed to this article.