The Bombay Stock Exchange benchmark Sensex today lost over 200 points in afternoon trade after opening 36 points up. It was trading at 18,443, down by over 240 points a short while ago. On global front, the US Dow Jones Industrial Average ended marginally higher by 0.04 per cent in yesterday's trade. In Asian markets, Japan's Nikkei lost 0.15 per cent in the morning trade today.