World oil prices jumped Wednesday as a cautious Federal Reserve statement offset data showing a big increase in US crude inventories.
US benchmark West Texas Intermediate gained $1.20 to $44.66 a barrel after earlier falling to a new six-year low.
European benchmark Brent oil for May delivery advanced $2.40 to $55.91 a barrel.
Crude prices surged after the Fed's 1800 GMT statement, which noted that US economic growth had "moderated somewhat" since January.
The Fed dropped a pledge to remain "patient" on raising interest rates, signaling a midyear federal funds rate hike remained possible after keeping it at the zero level for more than six years.
But other language in the Fed's statement emphasized that the central bank was in no rush to hike rates, sending the dollar lower.
"It looks like there's a little hesitation on when the Fed is going to raise rates," said Gene McGillian, a broker and analyst at Tradition Energy.
McGillian noted that the strong dollar has been a factor in the long decline in oil prices, which have fallen about 60 percent since last June. Oil is traded in dollars.
The oil market had spent most of the session in negative territory amid worries about a global supply glut, made worse by the 10th straight weekly increase in US crude inventories.
Data from the US Department of Energy showed US crude stocks jumped 9.6 million barrels for the week ending March 13, taking inventories to the highest level in at least the last 80 years.
The report showed US production also rose, by 0.6 percent in the week to 9.4 million barrels.
"There should be some supply response at some point, but we're not there yet," said John Kilduff, founding partner at Again Capital.