The Bombay Stock Exchange benchmark Sensex plunged over 439 points on frantic selling by funds in view of a weakening trend on the global front.
The 30-share index, Sensex, which commenced the day lower by 194 points, fell further to record a loss of 439.68 points at 17,635.98 at 1200 hours.
Similarly, the wide-based National Stock Exchange index Nifty lost 135.60 points at 5,145.20 as most of the heavy-weights like Reliance Industries, Tata Steel, Larsen and Toubro declined sharply.
A selling pressure gathered momentum following reports of a steep fall in global stock markets, traders said.
They said an upward march in information technology stocks on government plans to provide more sops to export business, saved the market from any further major fall.