Oil prices are lower as Europe's ongoing debt crisis fueled concerns about future energy demand.
Benchmark crude on Monday fell 47 cents to $86.33 per barrel in New York, while Brent crude fell $1.38 at $110.85 in London.
Oil has tumbled 24 percent since May on fears of a slowdown in the global economy. Investors focused on weak gasoline demand in the U.S. and budget problems in Greece.
Prices had started to rise last week as European leaders appeared to be near a turning point. But on Monday German finance chief Wolfgang Schaeuble dampened expectations that they'd hammer out a solution.
Meanwhile, gasoline pump prices rose a half penny to a national average of $3.462 per gallon.