The Bombay Stock Exchange benchmark Sensex fell by almost 155 points in the opening trade today, amid profit-booking and a weak trend in the Asian region. The 30-share barometer that had shed 46.67 points in the yesterday session, declined further by 154 points or 0.77 per cent to 19,780 points today.Similarly, the wide-based National Stock Exchange index Nifty also lost by 35 points or 0.58 per cent to trade at 5,941 level.In Asia, Hong Kong's Hang Seng index was trading 0.79 per cent low, while Japan's Nikkei was marginally up by 0.81 per cent in the early trade today. In the US, the Dow Jones Industrial Average ended 0.03 points down in the yesterday's trade.