Monopolies

If Chrysler and GM had been permitted/forced to declare bankruptcy months ago then there would not have been massive amounts of government money owed by those two companies.  As it was the debt owed allows the government to claim a majority ownership of both companies.If the single entity owning a majority of GM and Chrysler were not the US government would they be subject to a anti trust ruling from the federal government?How much collusion will there be between Chrysler and GM in the future with a common majority shareholder?