From their investor website -
http://www.gm.com/corporate/investor_information/:
"General Motors Company (the "new GM") currently has no publicly traded securities. Please note that none of the publicly owned stocks or bonds issued by the former General Motors Corporation (now renamed "Motors Liquidation Company"), including its common stock currently traded on the Pink Sheets over-the-counter market under the ticker symbol "MTLQQ", are or will become securities of General Motors Company, which is an independent separate company."
From WikiAnswers -
http://wiki.answers.com/Q/What_is_th...rs_Corporation
"General Motors has emerged from bankruptcy and the new GM is no longer publicly traded. It is privately owned by various interests such as the US Government, the Canadian government, bond holders, and the Auto Workers Union. The old General Motors (GM then changed to GMGMQ) has been renamed and given a new ticker symbol. It is now known as Motors Liquidation Company MTLQQ. These shares represent most of the bad assets of General Motors and GM has said that even with the most optimistic of results little to no value will be associated with these shares.
MTLQQ continues to trade due to the fact that 'Short Sellers' had sold this stock without owning it. So at some point they must buy it back to replace the borrowed shares they did not own. Others are laying in wait for these buys happen and until they do, the stock will have some value. MTLQQ is a liquidation company so there could be some value left after the sale of assets but GM has publicly stated they expect little to no value to come from this process as a shareholder of the liquidation company itself. "