West Texas Intermediate and Brent crudes dropped as a stronger dollar curbed the appeal of commodities to investors looking for a store of value.

Futures dropped as much as 0.9 percent in New York and 1 percent in London. The dollar reached a six-year high against the yen after the Federal Reserve increased its outlook for interest rates. Libya's Sharara field, the country's biggest-producing asset, was shuttered while a strike by oil workers in Nigeria entered a third day.

"The focus has been on interest rates and that's pushed the dollar higher, which is hurting demand for commodities," Phil Flynn, senior market analyst at the Price Futures Group in Chicago, said by phone. "Oil would be much lower if not for the trouble in both Libya and Nigeria."

WTI for October delivery fell 65 cents, or 0.7 percent, to $93.77 a barrel at 10:14 a.m. on the New York Mercantile Exchange after earlier sliding to $93.62. The volume of all futures traded was 4.7 percent above the 100-day average for this time of day. Prices have decreased 4.7 percent this year.

Brent for November settlement fell 82 cents, or 0.8 percent, to $98.15 a barrel on the London-based ICE Futures Europe exchange. Volumes were 14 percent lower than the 100-day average. The European benchmark crude was at $5.51 premium to WTI for the same month.