MUMBAI: The rupee weakened by four paise to end at 40.16/17 a dollar on Monday on sustained demand by oil refiners. Dealers said the market was cautious ahead of Tuesday’s announcement of annual credit policy by the Reserve Bank and the meeting of the U.S. Federal Reserve on April 29-30. It closed at 40.12/13 on last Friday. The rupee moved in a wide range of 40.10 and 40.2150 after resuming on a promising note at 40.10/12 a dollar. Weakness in local stocks also weighed on the rupee sentiment. — PTI