* Brent premium to U.S. crude at widest since March
* Yellen says Fed has more work to do to help economy
NEW YORK, Nov 14 (Reuters) - Brent oil prices rose on Thursday supported by disruptions to Libyan output, while U.S. crude dipped as traders weighed bulging U.S. inventories, but both markets drew support from expectations the Federal Reserve would keep stimulus measures in place.
Brent's premium to U.S. oil futures shot to an eight-month high of $15.87 a barrel during intraday activity as the U.S. contract dipped to $92.51 a barrel, the lowest level since early June.
Traders cited government data showing the eighth straight week of U.S. stockpiles builds and the fifth increase at the Cushing, Oklahoma, delivery point for the U.S. contract as dragging down prices.
International benchmark Brent, however, found support from ongoing supply problems from OPEC member Libya. Oil and other asset classes also found support from confirmation by incoming Federal Reserve chief Janet Yellen that the U.S. central bank's loose monetary policy could be extended.
U.S. gasoline futures showed the biggest gains on the day, however, up more than 2 percent as data from the U.S. Energy Information administration showed inventories declined for a fifth straight week amid seasonal refinery maintenance.
"The momentum is coming from this speech and gasoline is up big," said Bill Baruch, senior market strategist at iitrader.com in Chicago.
The December Brent contract, which expired on Thursday, traded up $1.42 to settle at $108.54 a barrel after breaking above its 200-day moving average for the first time in almost two weeks. The contract has rallied by more than 5 percent since hitting a four-month low near $103 a barrel last week, supported by the supply outages in Libya.
The more actively traded January Brent contract settled $1.39 higher at $108.28 a barrel.
U.S. crude slipped 12 cents to settle at $93.76 a barrel, after earlier trading as high as $94.43.
U.S. RBOB gasoline futures rose 5.57 cents to settle at $2.6837 a gallon, extending a rebound after hitting $2.50 a gallon in early November, the lowest level since December 2011.
"I think it's a technical correction and that the market is showing us that $2.50 is pretty good support for gasoline," said
Gene McGillian, analyst for Tradition Energy in Stamford, Connecticut.
International benchmark Brent crude found early support amid concerns disruptions from Libya could tighten global oil markets.
The International Energy Agency (IEA) said the oil market currently looked well supplied, but that the production problems in Libya and Iraq, as well as increased demand from the Northern Hemisphere's winter, could lift prices following recent weakness.
The EIA report showed crude oil inventories in the world's largest oil consumer rose by 2.6 million barrels last week, far more than the 1 million barrels predicted by analysts. Stocks at the Cushing storage hub rose by 1.7 million barrels.