Shares in General Motors fell below $US1 on Friday as the company heads toward bankruptcy.
The 100 year old company was once the world's top automaker.
At 1550 GMT, the share, which was worth almost $US30 in early 2008, plunged 20.93% from a day earlier to 88 US cents.
The company's capitalisation is now less than $US550 million.
GM was finalising a pre-packaged bankruptcy plan that would give the US government up to 72.5% of the new company.
GM is under a deadline of 1 June imposed by the administration of President Barack Obama, to file for bankruptcy protection.