The Sensex was trading down 46 points at 20,805, a shortwhile ago. It fell 91 points in early trade today on sustained selling by funds and investors amid a weakening trend in other Asian markets. Similarly, the National Stock Exchange index Nifty shed 12 points to 6,198.In the Asian region, Hong Kong's Hang Seng index shed 0.56 per cent, while Japan's Nikkei fell 2.18 per cent in early trade today.