The Sensex at the Bombay Stock Exchange was trading 176 points in the negative territory at 18,443 in late morning deals, when reports last came in. Extending its losses for the fifth trading day in a row, the Sensex opened 168 points the red today, as stocks of IT, FMCG and healthcare sectors fell on sustained selling by funds and retail investors, amid a weak trend overseas.The Nifty at the National Stock Exchange was trading 54 points in the negative zone at 5,613.In Asia, Hong Kong's Hang Seng index fell by 1.18 per cent, while Japan's Nikkei was up 0.96 per cent in opening trade. The US Dow Jones Industrial Average tumbled 1.45 per cent to its lowest close since June 26 lower in yesterday's trade.