After gaining 703 points in the last four sessions, the Sensex plunged 746.20 points, or 3.85 per cent, to 18,621.39 at 1430 hrs as stocks led by consumer durables and banking sector suffered major losses.
The broad-based National Stock Exchange index Nifty nosedived by 233.05 points, or 4.05 per cent to 5,509.25.
Brokers said trading sentiment dampened on increased selling by foreign funds as rupee fell to record low of 62 per dollar raising fears of slowing economic growth.
Today major losers were Reliance Industries, BHEL, Maruti, HDFC, Sterlite Industries and ICICI Bank.