Investing.com - West Texas Intermediate oil futures extended losses on Wednesday, after data showed that oil supplies in the U.S. rose unexpectedly last week.
The U.S. Energy Information Administration said in its weekly report that crude oil inventories increased by 4.8 million barrels in the week ended December 11. Market analysts' expected a crude-stock drop of 1.4 million barrels, while the American Petroleum Institute late Tuesday reported a supply gain of 2.3 million barrels.
Supplies at Cushing, Oklahoma, the key delivery point for Nymex crude, rose by 607,000 barrels last week, above forecasts for a gain of 500,000 barrels.
Total U.S. crude oil inventories stood at 490.7 million barrels as of last week, remaining near levels not seen for this time of year in at least the last 80 years.
Gasoline inventories increased by 1.7 million barrels, compared to expectations for a gain of 2.0 million barrels, while distillate stockpiles rose by 2.6 million barrels.
Crude oil for delivery in January on the New York Mercantile Exchange slumped $1.16, or 3.11%, to trade at $36.19 a barrel during U.S. morning hours. Prices were at around $36.70 prior to the release of the inventory data.
A day earlier, Nymex futures rallied $1.04, or 2.85%, after Congress lifted a 40-year-old ban on most U.S. crude exports as part of a broader spending bill. Prices fell to a six-and-a-half-year low of $34.53 on Monday.
U.S. oil futures are down 30% so far this year amid worries over ample domestic supplies.
Elsewhere, on the ICE Futures Exchange in London, Brent oil for February delivery dropped $1.14, or 2.96%, to trade at $37.58 a barrel as worries that a global supply glut may stick around for longer than anticipated continued to weigh.
On Tuesday, London-traded Brent tacked on 57 cents, or 1.49%. Futures sank to $36.75 on monday, a level not seen since the depths of the 2008 global financial crisis.
Brent oil prices are on track to post an annual decline of 32% in 2015, as oversupply concerns dominated market sentiment for most of the year.
Oil futures have fallen sharply this month after the Organization of the Petroleum Exporting Countries failed to agree on output targets to reduce a glut of oversupply on global energy markets.
Global crude production is outpacing demand following a boom in U.S. shale oil and after a decision by OPEC last year not to cut production in order to defend market share.
Meanwhile, the spread between the Brent and the WTI crude contracts stood at $1.39 a barrel, compared to $1.38 by close of trade on Tuesday.
The price gap between the two benchmarks has narrowed to the smallest level in months, signaling that the U.S. oil market is likely to grow tighter following Congress' decision to lift the ban on domestic oil exports, while a global glut gets worse.
Market participants awaited the Federal Reserve's highly-anticipated policy decision due at 2:00PM ET on Wednesday. Most investors expect the Fed to raise interest rates for the first time since June 2006.