The Sensex at the Bombay Stock Exchange failed to retain initial gians and fell 204 points in the late morning trade following RBI's monetary policy review. The 30 share barometer which had gained 14 points in early trade today, declined by 204 points to a low of 18,432 when reports last came in. Similarly, the wide-based National Stock Exchange index Nifty slipped by 70 points to 5,595 a short while ago.