Mumbai, Oct 4 (IANS): India's benchmark equity index, the S&P BSE Sensex, plunged over 700 points in the afternoon session on Thursday, as a steady decline in the domestic currency and concerns that the central bank would raise the policy interest rate soured investor sentiments.

The wider Nifty50 of the National Stock Exchange also lost 240 points.

The Indian rupee earlier on Thursday sunk to its fresh low of 73.77 to a dollar, as global crude oil prices continued to climb. India imports nearly 80 per cent of its crude requirements, and a higher price will potentially worsen the current account deficit of Asia's third-largest economy.

The Reserve Bank of India will unveil its monetary policy on Friday, where it is likely to raise the repurchase rate by 25 basis points. The repo rate currently stands at 6.5 per cent.

At 1.20 p.m., the Indian rupee had recouped some of its losses and was trading at around 73.64 against the US dollar.

NSE's Nifty50 traded at 10,618.25 points at 1.20 p.m., down 240 points or 2.21 per cent from its previous close.

The S&P BSE Sensex, which opened at 35,820.53 points, traded at 35,211.94 points, down 763.69 points, or 2.12 per cent.

So far, the Sensex has touched an intra-day high of 35,820.53 points and a low of 35,116.82.