BSE and NSE have restricted trading instocks of as many as 40 new companies on account of their failure in meeting the market regulator Sebi's direction on dematerialising of shares. 

The action comes after these companies failed to convert a mandatory 50% public shareholding into demat or electronic format, or either they did not submit the shareholding data for July-September quarter or provided the exchanges with wrong shareholding patterns. 

The restriction in trading of these 40 stocks comes on top of shares of close to 500 companies already being kept under restricted-trade category by the two bourses. 

As per Sebi regulations, shares of all listed companies having less than 50% public holding in demat form need to be traded only in the 'Trade-for-trade' segment of the exchanges. 

In a circular, BSE has listed out 39 such stocks that are being moved to 'Trade-for-Trade' group with effect from November 23, 2012. The NSE has also listed out three such stocks, which includes two named by BSE as well, taking the total number of such stocks to 40. These include Deccan Chronicle Holdings, Falcon Tyres,Ion Exchange India, Prithvi Information Solutions, Rama Vision and Vikash Metal and Power. In addition, BSE said that 459 stocks would continue to be traded on 'Trade-for-Trade' basis due to their non-compliance to Sebi's demat shareholding norms. 

These companies include Austral Coke and Projects , Bhilwara Spinners, Dhanlaxmi Cotex, India Cements Capital, Jaybharat Textiles and Real Estate, Oswal Yarns, Sakthi Finance and Zenotech Laboratories.