West Texas Intermediate dropped as world powers held talks with Iran on its nuclear program and the dollar strengthened amid optimism that Senate leaders will reach an agreement to raise the U.S. debt limit.

Prices slid as much as 1.2 percent on Iranian proposals to end a decade-long standoff as two days of negotiations with the U.S., U.K., France, Germany, Russia and China started today in Geneva. Iran is demanding a relaxation of the international sanctions against its oil exports. The dollar advanced against the euro for the first time in three days as Senate leaders were poised to reach an agreement to halt the fiscal impasse.

WTI for November delivery declined 42 cents, or 0.4 percent, to $101.99 a barrel at 10:53 a.m. on the New York Mercantile Exchange. Trading volume was about 12 percent below the 100-day average.

Brent for November settlement, which expires tomorrow, fell 69 cents, or 0.6 percent, to $110.35 a barrel on the London-based ICE Futures Europe exchange. The more-active December contract lost 49 cents to $109.75. The front-month European benchmark was at a premium of $8.36 to WTI after narrowing for the first time in six sessions yesterday to $8.63.