Crude oil prices for October delivery eased back under $109 per barrel Monday after a Syrian official said a diplomatic solution to tensions there was possible, UPI reported. West Texas Intermediate crude oil for October delivery shed $1.56 to $108.97 per barrel. Reformulated blendstock gasoline dropped 6.82 cents to $2.7855 per gallon. Natural gas gave up 2.5 cents to $3.58 per million British thermal units. At the pump, the national average price of unleaded gasoline dropped to $3.57 per gallon Monday, down from Sunday\'s $3.571, AAA\'s daily fuel gauge report said.