West Texas Intermediate crude fell for a third day on rising U.S. supplies and as a stronger dollar weighed on commodity prices.

Stockpiles increased last week for the first time since Aug. 8, according to the Energy Information Administration. The Bloomberg Dollar Index headed for a fifth weekly gain as the Federal Reserve moves closer to raising interest rates. Brent widened its premium to WTI on signs of lower OPEC output.

"Oil continues to come under pressure from the idea that we have ample supplies," said Gene McGillian, an analyst and broker at Tradition Energy in Stamford, Connecticut. "The dollar is throwing pressure on oil."

WTI for October delivery dropped 98 cents, or 1.1 percent, to $92.09 at 10:28 a.m. on the New York Mercantile Exchange. The volume of all futures traded was about 3.3 percent above the 100-day average. Prices are poised for a third straight weekly loss. The October contract expires on Sept. 22.

Brent for November settlement fell 2 cents to $97.68 a barrel on the London-based ICE Futures Europe exchange, headed for a weekly gain of 0.6 percent. Volume was 28 percent below the 100-day average. WTI for November was at a discount of $6.37 to Brent for the same month, compared with $5.72 yesterday.