General Motors Corp filed for bankruptcy forcing the 100-year-old automaker once seen as a symbol of American economic might and dynamism into a new and uncertain era of government ownership.

The planned filing is the third-largest in US history and the largest-ever US manufacturing bankruptcy.

The decision to push GM into a fast-track bankruptcy, and provide $30 billion of additional taxpayer funds to restructure the automaker is a huge gamble for the Obama presidency.

But in a sign of progress in the government's high-stakes effort, a bankruptcy judge approved the sale of substantially all of US automaker Chrysler's assets to a group led by Italy's Fiat SpA in an opinion filed late on Sunday.

Chrysler's bankruptcy, also financed by the US Treasury, has been widely seen as a test run for the much bigger and more complex reorganization of GM.