The local unit resumed lower at 66.27 as against last weekend's level of 66.19 at the Interbank Foreign Exchange (Forex) market and dropped further to 66.48 before ending at 2-month low of 66.47, showing a loss of 28 paise, 0.42 per cent.
The rupee had last ended at 66.54 on September 11, 2015. It hovered in the range of 66.24 to 66.48 during the day.
The US dollar held firm against a basket of six major currencies, helped by the euro's weakness.
The dollar index was trading up by 0.15 per cent.
The euro extended its losses against the dollar in early Asian trade, hitting a seven-month low versus the US currency, on expectations that the European Central Bank will ramp up its monetary stimulus next month.
Meanwhile, oil prices fell in Asia today, extending their slide as a stronger dollar and news that world stockpiles have reached a record high, put pressure on futures.
The benchmark BSE Sensex fell by 49.15 points, or 0.19 per cent, to settle at 25,819.34. In forward market today, premium for dollar continued to decline on persistent receipts from exporters.
The benchmark six-month premium payable in April moved down further to 180-182 paise from the last weekend's level of 185.75-189.5 paise and far forward October 2016 contract fell to 387.5-389.5 paise from 395.5-397.5 paise. The RBI fixed the reference rate for the dollar at 66.34900 and for the euro at 70.4693.
The rupee recovered against the pound sterling to end at 100.54 from 101.20 on last Friday and moved up further against the euro to settle at 70.64 from 70.80.
However, the domestic currency moved down further against the Japanese currency to close at 53.98 per 100 yen from 53.91.