The Sensex at the Bombay Stock Exchange was down 53 points in late morning trade .The 30-share barometer, which fell by 43 points in its opening trade, moved down by 53 points to 19,712 when reports last came in.Similarly, the wide-based National Stock Exchange index Nifty, dipped below the 6,000-mark by losing 18 points to 5,991 a short while ago.