Oil prices stabilized on Thursday, but remained under pressure as rising U.S. production and inventories threatened to undermine a rally sparked by tightening world supply.
U.S. light crude ended the session down 19 cents to $55.14, posting its a fourth straight day of declines and the weakest closing price in two weeks.
Brent crude oil fell 32 cents a barrel to $61.55 by 2:14 p.m. ET (1814 GMT), on track for its fifth consecutive drop.
Oil prices have slipped from the two-year highs hit last week by both crude benchmarks on signs that U.S. supply is rising and could potentially undermine OPEC's efforts to tighten the market.
Concerns about consumption also emerged after the International Energy Agency cut its forecast for demand growth in 2017 and 2018.
The U.S. Energy Information Administration on Wednesday showed domestic crude inventories rising for a second week in a row, building by 1.9 million barrels in the week to Nov. 10 to 459 million barrels. Stockpiles of gasoline also surprisingly rose.
The United States is expected to account for more than 80 percent of the growth in world crude supply in the next decade, the International Energy Agency said on Thursday, and weekly data shows ongoing boosts in production.
U.S. crude oil production has hit a record of 9.65 million barrels per day, meaning output has risen by almost 15 percent since its mid-2016 low.
By contrast, RBC commodity strategist Michael Tran noted on Thursday that most of the rest of the world's inventories are in line with historic averages.
"It is no coincidence that the recent price rally has occurred concurrently with several weeks of record setting surges in exports," he wrote.
Expectations that a meeting of the Organization of the Petroleum Exporting Countries in Vienna on Nov. 30 would result in OPEC nations and other big exporters extending their pact to tighten supply has offset some of the pressure on prices.
OPEC and other big exporters including Russia 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.
Oil ministers have signaled that they are likely to extend the agreement, possibly until the end of next year.
"It is widely believed that OPEC and non-OPEC nations will roll over their production until (end) 2018," said PVM Oil Associates analyst Tamas Varga.
"If they don't, or if the period will be shorter than nine months, I think we will see even lower prices. Brent would break back below $60 a barrel."
Markets are keeping a close eye on statements from the key architects of the deal — Saudi Arabia and Russia — for clues on how the extension will play out.
"Russia is sending out quite mixed signals ... that may be yet another reason why the market is coming lower," Varga said.