The Bombay Stock Exchange benchmark Sensex declined by over 71 points in opening trade today on sustained selling by funds and retail investors.The 30-share BSE index, which has lost nearly 800 points over the previous three sessions, fell by 71 points, or 0.44 per cent, to 16,396 in the first five minutes of trade. The National Stock Exchange Nifty index lost 13.45 points, or 0.27 per cent, to 4,927. In the Asian region, Hong Kong's Hang Seng Index rose by 0.96 per cent, while Japan's Nikkei Index shed 0.20 per cent in early trade today.