The BSE benchmark Sensex dipped below the 16,000 points level in early trade today by losing 232 points on heavy selling by funds and retail investors, tracking weak global markets. The 30-share barometer, which had closed higher by 40 points in yesterday's session, tumbled by 232 points to 15,839.The wide-based National Stock Exchange index Nifty too dipped below the crucial 4,800 points level. It was trading lower by 74 points to 4,796.In the Asian region, the Hong Kong's Hang Seng index fell by 2.23 per cent, while Japan's Nikkei was down by 2.44 per in the early trade.The US Dow Jones Industrial Average lost 1.24 per cent in yesterday's trade.