The Bombay Stock Exchange benchmark Sensex today fell by over 205 points in the opening trade, largely on profit-booking. The 30-share barometer, which had gained 372 points in the previous trading, was quoted at 19,785 points in the opening trade, down by 205 points from Monday's close. Similarly, the wide-based National stock Exchange index Nifty also fell by 70 points to 5,939.Brokers said fresh bout of selling by funds and retailers on prevailing levels amid weak trend in global markets weighed down the trading sentiments.In other Asian markets, the Hong Kong's Hang Seng index was quoted down by 1.23 per cent in the morning trade.Japanese markets are closed today. In the US, Dow Jones Industrial Average shed 0.22 per cent in Monday's trade.