The benchmark BSE Sensex fell over 400 points, for the fourth straight session, dragged by banking and auto stocks, amid negative cues from global markets. The 30-share BSE index slipped 435 points (0.85%) to close at 50,890; while the broader NSE Nifty settled 137 points (0.91%) lower at 14,982. Some of the top losers in the Sensex pack include Axis Bank, ICICI Bank, ONGC, SBI, Bajaj Auto and Maruti.