The BSE benchmark Sensex nosedived by 185 points in late morning trade soon after RBI kept rates unchanged in its mid-quarterly review of the monetary policy. After falling over 103 points in early trade, the 30-share index fell further by 185.22 points to trade at 17,734.08 a shortwhile agoAll the sectoral indices, led by banking and consumer durables, were trading in the negative zone with losses upto 2.09 per cent.In a similar fashion, the broad-based National Stock Exchange index Nifty dipped below 5,400 points level by losing 62.75 points to 5,401.15 points.