Crude oil prices slipped under $98 per barrel on the New York Mercantile Exchange Thursday, as traders reacted to purchasing managers index reports. Data on manufacturing from China came in under expectations, the index cropping from 51.4 to 51, suggesting lower than anticipated exports. The index from Europe showed a PMI at 52.7, a positive number that was in line with expectations. Levels above 50 indicate growth. Light, sweet crude on the NYMEX listing shed 67 cents to $97.75 per barrel. Reformulated gasoline blendstock for February gave up 3.02 cents to $2.7557 a gallon. January heating oil dropped 3.69 cents to $3.0283 a gallon while natural gas added 5 cents to $4.28 per million British thermal units. The national average price of unleaded regular gasoline rose at the pump, climbing to $3.325 a gallon from Tuesday's $3.323, the AAA Daily Fuel Gauge Report said.