West Texas Intermediate crude dropped, heading for a second monthly decline, as OPEC kept its output target unchanged for a third consecutive time and U.S. inventories climbed to the highest level in 82 years.

Futures fell as much as 1.5 percent after the Organization of Petroleum Exporting Countries maintained its target of 30 million barrels a day at a meeting in Vienna today. Ministers from the 12-member group will next gather on Dec. 4. U.S. crude supplies increased 3 million barrels to 397.6 million last week, the most since 1931, a government report showed yesterday.

OPEC has no formal target for prices, the group’s Secretary-General Abdalla El-Badri said at a news conference in Vienna after the ministers’ meeting.

Most member states also expressed their support for $100 oil. Some, including Venezuela, voiced concern over excessive production by other members, with OPEC pumping about 1 million barrels a day more than the informal target.

U.S. crude production rose 34,000 barrels a day to 7.29 million last week, the Energy Information Administration, the Energy Department’s statistical arm, reported yesterday. Output reached 7.37 million barrels a day in the week ended May 3, the most since February 1992. Production has surged as horizontal drilling and hydraulic fracturing, or fracking, have unlocked supplies trapped in shale formations in the central U.S.

Prices also dropped as the dollar rallied on better-than-forecast reports on U.S. business activity and consumer confidence. The Dollar Index, which tracks the currency against six others, rose as much as 0.7 percent to 83.597. The U.S. currency climbed as much as 0.8 percent against the euro, reducing the appeal of raw materials as an investment.

WTI crude for July delivery declined $1.06, or 1.1 percent, to $92.55 a barrel at 11:10 a.m. on the New York Mercantile Exchange. The volume of all futures traded was 38 percent below the 100-day average for this time of day. Prices are down 1.7 percent this week and 1 percent this month.

Brent oil for July settlement dropped $1.22, or 1.2 percent, to $100.97 a barrel on the London-based ICE Futures Europe exchange. Volume for all contracts was 16 percent lower than the 100-day average.