The BSE benchmark Sensex dipped below the psychological 18,000 points level in late morning trade on Thursday, shedding nearly 264 points as investors resorted to a massive sell-off amid growing unease in global markets.
The Bombay Stock Exchange benchmark, which opened in the negative zone, was down by 263.51 points, or 1.45%, at 17,914.82 at 1100 hrs.
Stocks of capital goods, banking, auto and metal firms were under pressure, dragging the Sensex down.
Similarly, the broad-based National Stock Exchange index Nifty also fell below the crucial 5,400 points level, losing 79.30 points, or 1.46%, to 5358.05.
Brokers said the trading sentiment was extremely bearish, dampened by a series of negative factors such as rising crude oil prices in global market amid the spiralling crisis in Libya and weakening equities in the global market.
In addition, the cautious approach adopted by participants on the last day of monthly expiry in the derivatives segment on the NSE, also cast its shadow on the trading sentiment, they said.