Oil prices rise on weaker dollar, but U.S. output drags

By Henning Gloystein SINGAPORE (Reuters) - Oil prices rose on Monday, with traders shifting money into crude futures as the dollar weakened, and on concerns that new U.S. sanctions against Iran could be extended to affect crude supplies. International Brent crude futures were trading at $57.01 per barrel at 0620 GMT, up 20 cents from their last close. U.S. West Texas Intermediate (WTI) futures were up 19 cents at $54.02 a barrel.