The BSE benchmark Sensex declined by over 88 points in early trade today, extending losses for the fourth straight session as funds and retail investors engaged in booking profit amid a weak trend in global markets. The 30-share barometer fell by 88 points, or 0.44 per cent, to 19,663.The index had lost nearly 254 points in the past three sessions.Similarly, the wide-based National Stock Exchange index Nifty fell by 39 points, or 0.65 per cent, to 5,948.In the Asian region, Japan's Nikkei Index was down 1.27 per cent, while Hong Kong's Hang Seng index shed 1.66 per centin early trade.The US Dow Jones Industrial Average ended 0.93 per cent down in yesterday's trade.