Rupee is fast approaching the crucial 43 level as the local unit lost nine paise at 42.96/97 against the greenback on Tuesday with demand from oil companies for dollar continuing amid inadequate supply of the US currency and sluggish equity markets.

At the Interbank Foreign Exchange (forex) market, the local currency resumed on a promising note at Rs 42.84/86 a dollar but later came under pressure and fell to 42.97 level as oil corporates stepped up dollar purchases. The rupee had closed at Rs 42.87/88 a dollar on Monday.

Dealers said oil refiners bought dollars at the current levels as global crude oil prices further shot up by about four dollars to around 134 dollars a barrel after the biggest single-day rise of 10 dollars on Friday.

A dealer with a private bank said with foreign institutional investors continuing to pull out from Indian equity markets, the dollar supply has become inadequate which has further dampened the rupee sentiments.

The capital outflows amounted to more than 4.5 billion dollars so far in the calendar year.

Meanwhile, the Indian benchmark Sensex today ended nearly 177 points down after touching the current year's low of 14,645.31. Asian indices fell by about 1.0 per cent to 4.0 per cent.

The rupee remained under pressure amid high inflation and anticipation of further tightening of monetary policy by the Reserve Bank, dealers said.