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. The 30-share Sensex, which had lost nearly 620 points in the previous three straight sessions, tanked another 467 points to trade at 17,226 points in the first few minutes of trade. The wide-based National Stock Exchange Nifty index dipped below crucial 5,200 level by losing 147 points to trade at 5,185 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. In the Asian region, Hong Kong's Hang Seng Index was down 4.81 per cent, while Japan's Nikkei lost 3.36 per cent. The Dow Jones Industrial Average in the US ended 4.31 per cent lower yesterday, its worst one-day drop since December 2008.