Declining for the fourth straight day, the rupee slipped by 10 paise to close at 21-month low of 64.26 on sustained dollar demand from banks and importers amid foreign capital outflows.
The rupee opened higher at 64.05 from its previous close of 64.16 at the Interbank Foreign Exchange (Forex) market on initial selling of dollars by banks and exporters.
However, it dropped afterwards to 64.30 before ending at 21-month low of 64.26 on fag-end dollar demand from banks and importers, a loss of 10 paise, or 0.16 per cent, from its last close after moving in a range of 64.05 and 64.30 during the day.
The rupee had last ended at 65.24 on September 6, 2013, and has dropped 42 paise or 0.66 per cent in last four days.
Bonanza Portfolio Senior Vice President Rakesh Goyal said, "The dollar is seen stronger amidst the two day US Fed policy review that starts today."
The trading range for the Spot USD/INR pair is expected to be within 63.80 to 64.60.
The dollar index was trading higher by 0.13 per cent against its major global rivals on Tuesday.
Meanwhile, the benchmark BSE Sensex closed 100 points up at 26,686.51.
Globally, the US dollar was steady in Asian trade with traders adopting a cautious stance as they wait for the outcome of the US Federal Reserve's two-day policy meeting that takes place amid the backdrop of a looming crisis in Greece.
In the forward market, the premium for dollar ended marginally higher on mild buying pressure from corporates.
The benchmark six-month premium payable in November ended at 205-207 paise as against 205-206 paise on Monday and those maturing in May, 2016 also closed slightly higher at 427-429 paise as against 426-428 paise.
The RBI fixed the reference rate for the dollar at 64.1505 and for the euro at 72.2720.
The rupee dropped further against the pound sterling to 100.35 from 99.45 on Monday and moved down further against the euro to 72.34 from 72.01 previously.
The domestic currency continued to decline against the Japanese unit to 52.05 per 100 yen from 51.92 previously.