Trimming intital gains, the Sensex at the Bombay Stock Excange stood 54 points, or 0.3 percent in positive territory, at 18,763 in afternoon deals, a short while ago. Earlier in the morning, however, the Sensex had opened with a much better gain of 151 points, or 0.8 per cent, at 18,860, on fresh buying by funds and retail investors, after two sessions of losses on profit-booking. The 30-share Sensex had lost nearly 350 points in the past two sessions.Key Asian markets in Japan, China, Singapore, South Korea, Taiwan, Hong Kong, and Indonesia were trading mixed, today. The US Dow Jones Industrial Average ended 0.2 per cent lower in yesterday's trade.