The Bombay Stock Exchange benchmark Sensex plunged by 467 points in early trade on heavy selling by funds and investors in line with melting global markets amid worries over the US economy and the European debt crisis.     The 30-share Sensex, which had lost nearly 620 points in the previous three straight sessions, tanked another 466.78 points to trade at 17,226.40 points in the first few minutesof trade.    

All the sectoral indices, led by realty, capital goodsand banking, were in the negative zone with losses up to 3.73 per cent.    

The wide-based National Stock Exchange Nifty index dipped below crucial 5,200 level by losing 147.30 points to trade at 5,184.50 points.    

Brokers said sentiments on the domestic boures remained extremely bearish after Asian stock markets plummets by nearly 5 per cent following overnight losses on the US market on fears the American economy is sliding back toward recession.