Crude futures edged slightly lower Tuesday in roller-coaster Asian trade as speculative buyers moved in ahead of the U.S. petroleum data snapshot that may show a fall in oil and gasoline stocks. Several refineries in Japan meanwhile, halted sea-borne deliveries as a precautionary measure as Tropical Storm Banyan moved toward Central Japan as OPEC's output is likely to exceed 30 million barrels per day in July -- an indication that demand has not slowed despite lofty prices. Midmorning in Singapore, light, sweet crude for September delivery was down 4 cents to $58.96 a barrel in Asian trading hours after earlier trading between $58.83 and $59.15 a barrel. The contract had risen 35 cents to settle at $59 Monday in New York floor trade. Oil prices are around 40 percent higher than a year ago and reached an intraday high of $62.10 a barrel July 7. On Wednesday, the U.S. Department of Energy will release its midweek petroleum inventories report that analysts predict will show a fall in crude and gasoline stocks. Another fall would mean stock levels have fallen for four straight weeks. Analysts believe stocks will fall because of increased refinery utilization to cater for peaking demand across North America and because of hurting production in the Gulf of Mexico, which forced precautionary shutdowns throughout July from Hurricanes Dennis and Emily. "The market is watching the U.S. inventory report. A drop in inventories could happen from the refinery runs," said Victor Shum, oil analyst at Purvin & Gertz in Singapore. Refinery utilization rates are already consistently above 90 percent in the United States, the U.S. Energy Information Administration said. "There is some speculative buying, and its really driven by bullish traders interpreting the impact of the yuan revaluation to China boosting oil demand," said Shum.