SINGAPORE, Dec 6 (Reuters) - Oil prices rose by more than $1 a barrel on Monday after top exporter Saudi Arabia raised prices for its crude sold to Asia and the United States, and as indirect U.S.-Iran talks on reviving a nuclear deal appeared to hit an impasse. Brent crude futures for February gained $1.69, or 2.4%, to $71.57 a barrel by 0033 GMT while U.S. West Texas Intermediate crude for January were at $67.92 a barrel, up $1.66, or 2.5%.