May moved down to 160-162 paise from last Friday's close of 164-165 paise.
Far-forward contracts maturing in November also ended lower at 304-1/2-306-1/2 paise from 309-1/2-311-1/2 paise. The RBI has fixed the reference rate for the US dollar at 54.6290 and for euro at 71.8595.
The rupee remained weak against the pound sterling to 88.86 from last close of 87.82 and also dropped further against the euro to 72.16 from 71.35.
It, however, reacted downwards against the Japanese yen to end at 65.53 per 100 yen from previous close of 65.04.