Continuing its gaining streak for the sixth day, the rupee Wednesday strengthened by nine paise to close at a fresh four-month high against the US currency amid heavy portfolio inflows.

At the Interbank Foreign Exchange (Forex) market, the domestic unit closed higher by 9 paise at 45.58/59, level not seen since 14th May 2010 when it had ended at 45.21/22.

Foreign Institutional Investors (FIIs) remained net buyers throughout the month and they injected over USD 4 billion in the current month till 21st September which mainly supporting the rupee continuously.

Dollar selling by some banks and exporters in early trade and a weak dollar overseas also helped the rupee rally, dealers said.

The US currency was trading lower in London Wednesday and the dollar index of six major currencies was down by nearly 0.45 per cent to nearly six-month low after US Federal Reserve Tuesday hinted that it could take more monetary easing measures.

The rupee opened strong at 45.47/48 a dollar from its last close of 45.67/68 and improved further to the day’s high of 45.45 in line with firm local stocks and sustained increased capital inflows.

However, weakness in equities and some dollar demand from importers, mainly oil refiners, for the second straight day later weighed on the rupee and it fell back to a low of 45.62 before concluding at 45.58/59.

The BSE benchmark Sensex ended lower by nearly 60 points.

Meanwhile, crude oil was trading above USD 75 in London Wednesday.

The rupee premium for the forward dollar ended strong on sustained paying pressure from banks and corporates.

The benchmark six-month forward dollar premium payable in February closed higher at 112-114 paise from 108-110 paise on Tuesday and far-forward maturing in August hardened to 219-221 paise from 210-212 paise previously.

The Reserve Bank of India has fixed the reference rate for the dollar at Rs 45.53 and the euro at Rs 60.58.

In cross-currency trade, the domestic unit dropped against the pound sterling, the euro and the Japanese yen.

The rupee fell back to Rs 71.41/43 against the pound sterling from Tuesday’s close of Rs 70.91/93 while dipped further to Rs 60.96/98 against the euro from Rs 59.96/98 previously.

It also remained weak against the yen at Rs 53.86/88 per 100 yen from its last close of Rs 53.48/50.