The BSE benchmark Sensex fell by almost 110 points in opening trade today on continued selling by foreign funds and retail investors. The 30-share barometer, which lost over 226 points in the previous three sessions, moved down further by 109 points to 18,159 in the first few minutes of trade today.Similarly, the wide-based National Stock Exchange Nifty index slid by 35 points to 5,451.In the Asian region, Hong Kong's Hang Seng index was trading 0.82 per cent lower and Japan's Nikkei shed 0.77 per cent this morning. In the US, the Dow Jones Industrial Average ended 1.42 per cent lower in Friday trade.