The BSE benchmark Sensex today fell over 225 points to plunge below the 19,000 mark in early trade led by over six per cent drop in Sun Pharma, after the pharmaceutical major and Israel's Teva agreed to pay 2.15 billion US Dollars patent infringement settlement to Pfizer and Takeda.Falling for the third straight session, the 30-share barometer fell further by 225.56 points to 18,815.57 with all the sectoral indices, led by healthcare andauto, falling up to 1.79 per cent. The index had lost nearly 400 points in the previous two sessions.Similarly, the wide-based National Stock Exchange index Nifty slipped below 5,700 points mark trade 60.25 points, or 1.05 per cent lower at 5,699.95