The Sensex at the Bombay Stock Exchange fell 85 points, or 0.4 per cent, to slip below the 20,000 level, at 19,978 in opening trade, this morning, on sustained selling by funds, amid falling global markets. Later, selling pressure intensified, and the Sensex had lost a hefty 330 points, or 1.7 percent, to stand at 19,732 in afternoon trade, a short while ago. The 30-share Sensex had declined over 220 points in the previous three trading sessions.Global markets also fell, with the bourses in Japan, Hong Kong, Indonesia, Singapore, Taiwan and South Korea dropping between 0.5 percent and 3.3 percent, today, amid speculation that the US central bank may soon wind back stimulus measures if economic conditions improved. Over on Wall Street, the Dow Jones Industrial Average had ended 0.5 per cent lower in yesterday's trade.