Mumbai: Extending losses for the second day, the Bombay Stock Exchange benchmark Sensex closed 86 points down on Wednesday, a day after the Reserve Bank raised key policy rates to tame inflation.

After recording the biggest loss of 353 points in five weeks yesterday, the 30-share index opened on a positive note but soon plunged by 160 points to touch the day's low of 18,358.76 points

It finally recovered some of the losses to end the day at 18,432.25, lower by 85.97 points from its previous close.

The 50-share National Stock Exchange index Nifty lost 28.05 points to 5,546.80 at close.

Marketmen said the investor sentiment remained dampened after the RBI's shocking 50-basis point hike in key repo and reverse repo rates.

They added that approaching current month expiry in derivatives segment further fuelled selling as investors squared up their positions on fears of further fall in the stock prices.

A mixed trend in the Asian region and lower opening in Europe following deepening debt crisis in the US too weighed heavily on investors, they said.

The capital goods sector index suffered the most by losing 1.86 per cent, followed by the power index that fell 1.51 per cent. Banking index was down 1.04 per cent, realty index 0.98 per cent and auto 0.12 per cent.

Country's biggest lender State Bank of India ended a sharp 1.58 per cent down. Tata Motors was another big loser at 1.68 per cent.