Shares in the 35 suspended firms - which are not traded on stock exchanges - are listed instead on the so-called Pink Sheets electronic quotation service, which does not require brokers to investigate the background of the companies.

BBC: Last Updated: Friday, 9 March 2007, 11:00 GMT

Stocks in the Over-The-Counter market are quoted on systems like the OTC Bulletin Board, an electronic quotation system, and the Pink Sheets, which is not registered as a stock exchange and is named for the color of paper on which its listings of price quotes for companies have historically been printed.

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