The Sensex at the Bombay Stock Exchange, which rose by over 250 points in early trade today, lost some ground in the late morning deals and was trading 159 points in the positive territory at 17,890. The 30-share index extended its gains for the second straight day today, with the Sensex surging 269 points in the opening trade.The wide-based National Stock Exchange index Nifty was trading 40 points up at 5,416.In Asia, Hong Kong's Hang Seng Index rose by 0.20 per cent, while Japan's Nikkei index was up by 0.69 per cent. The US Dow Jones Industrial Average gained 0.18 per cent to reach highest level since May 2008 in yesterday's trade.