Investing.com - West Texas Intermediate oil futures extended losses on Wednesday to trade below the key $50-level after data showed that oil supplies in the U.S. rose unexpectedly last week.
On the New York Mercantile Exchange, crude oil for September delivery hit a session low of $49.75 a barrel, a level not seen since April 6, before trading at $49.88 during U.S. morning hours, down 98 cents, or 1.93%. Prices were at around $49.97 prior to the release of the inventory data.
The U.S. Energy Information Administration said in its weekly report that U.S. crude oil inventories rose by 2.5 million barrels in the week ended July 17.
Market analysts' expected a crude-stock fall of 2.3 million, while the American Petroleum Institute late Tuesday reported an increase of 2.3 million barrels.
Supplies at Cushing, Oklahoma, the key delivery point for Nymex crude, increased by 813,000 barrels last week, compared to forecasts for an increase of 300,000 and following a gain of 438,000 barrels a week earlier.
Total U.S. crude oil inventories stood at 463.9 million barrels as of last week, remaining near levels not seen for this time of year in at least the last 80 years.
The report also showed that motor gasoline inventories decreased by 1.7 million barrels, while distillate stockpiles increased by 0.2 million barrels.
New York-traded oil futures have been under heavy pressure in recent weeks as worries over high domestic U.S. oil production weighed.
Elsewhere, on the ICE Futures Exchange in London, Brent oil for September delivery slumped 62 cents, or 1.08%, to trade at $56.42 a barrel.
London-traded Brent prices have been weighed by concerns over a resumption of Iranian oil exports, which could add to a global supply glut.
Iran and six world powers reached a long-awaited nuclear deal last week that would end sanctions on Tehran in exchange for curbs on the country's disputed nuclear program.
Iran reportedly hoards 30 million barrels of oil in its reserves ready for export. However, analysts largely estimate that Iranian crude exports could take several months to ramp up significantly.
Global oil production is outpacing demand following a boom in U.S. shale oil production and after a decision by the Organization of Petroleum Exporting Countries last year not to cut production.
The spread between the Brent and the WTI crude contracts stood at $6.54 a barrel, compared to $6.18 by close of trade on Tuesday.