Oil slid on concern the European debt crisis is worsening and on speculation that the biggest gain in more than a month was excessive.

Crude dropped as much as 0.8 percent after Italian Prime Minister Mario Monti warned of a potential breakup of Europe without greater urgency in efforts to lower government borrowing costs. Oil surged on Aug. 3 as a government report showed U.S. payrolls climbed more than estimated.

Oil for September delivery slid 66 cents, or 0.7 percent, to $90.74 a barrel at 9:15 a.m. on the New York Mercantile Exchange. It rallied 4.9 percent on Aug. 3, the biggest gain since June 29. Prices are 8.2 percent lower this year.

Brent crude for September settlement fell 87 cents, or 0.8 percent, to $108.07 a barrel on the London-based ICE Futures Europe exchange.