Oil extended losses on Wednesday, reversing a four-session rally after U.S. crude inventories jumped to a record high, shifting the global glut back in to focus.
Crude's nearly 20-percent surge since Friday had raised speculation oil's seven-month rout may be at an end, but the sharp sell-off on Wednesday indicated prices may not yet have found a floor, with the market still well supplied.
The U.S. Energy Information Administration said U.S. crude stocks rose by 6.3 million barrels last week to 413.06 million barrels, the highest level since records began in 1982. It was also the fourth consecutive weeks of gains.
Crude stocks at Cushing, Oklahoma, delivery point of the U.S. crude oil contract rose by 2.5 million barrels, while gasoline and distillate stocks also jumped.
U.S. crude futures settled down 8.7 percent, at $48.45 a barrel, posting its largest one-day percentage drop since November 28, 2014. It closed up 7 percent on Tuesday, after trading at $54.24 earlier in the day—above a near six-year low of $43.58 hit last week.
Brent crude was $4 lower at $54 a barrel, having traded as high as $59 a barrel on Tuesday—well above lows for the year close to $45 a barrel hit two weeks ago.