U.S. crude prices rose on Monday in very choppy and thin trading as investors were still cautious ahead of the U.S. presidential election. The trading was very light throughout the session as many investors chose to stay on the sidelines amid a great deal of uncertainty in the market ahead of an extremely tight election. However, oil prices got a boost as some bargain hunters stepped in after previous plunge. On Friday, crude tumbled nearly 3 percent, bringing the commodity to a third-straight weekly loss, as the U.S. government and suppliers took measures to deal with the fuel shortage in Northeast U.S. caused by Hurricane Sandy. Also contributing to the modest gain, some investors bet the demand will be slowly returning in the wake of hurricane as a bunch of refineries struggled to resume operations in the coming days. On the economic front, a report from the Institute for Supply Management showed the U.S. service sector expanded at a slower rate in October, with the ISM\'s nonmanufacturing purchasing managers index falling 54.2, from 55.1 in September. Light, sweet crude for December delivery added 79 cents, or 0. 93 percent, to settle at 85.65 dollars a barrel on the New York Mercantile Exchange. Brent crude for December delivery snapped a five-day losing streak, jumping 2.05 dollars, or 1.94 percent, to settle at 107.73 dollars a barrel.