NEW YORK (Reuters) - Oil futures edged lower on Monday as rising U.S.-China tensions weighed on market sentiment, but reports that OPEC and Russia were close to a deal extending output buoyed prices.Brent futures fell 37 cents, or 1%, to $37.47 a barrel by 11:10 a.m. (1510 GMT). U.S. crude fell $1.02, or 2.9%, to $34.47 a barrel.Investors turned cautious after China warned of retaliation on U.S. moves over Hong Kong.China has asked its state-owned firms to halt purchases of soybeans and pork..