The Sensex at the Bombay Stock Exchange fell 23 points in early trade today, ahead of current month expiry in the derivatives segment, amid a weak Asian trend. The 30-share index had gained 14 points in the previous session.The Nifty at the National Stock Exchange was down 4 points, or 0.07 per cent, to 6,051.Meanwhile, in Asia, Hong Kong's Hang Seng index declined by 0.10 per cent, while Japan's Nikkei by 0.61 per cent in opening trade. The US Dow Jones Industrial Average ended 0.32 per cent lower in yesterday's trade.