One of Ford Motor Company's prime investors says he is dumping his stake in the company, in what could be a major blow for the U.S. auto industry.

Billionaire financier Kirk Kerkorian revealed Tuesday, he has sold more than seven million of his shares in the company, and that he is looking to sell the rest.

Kerkorian gave Ford a vote of confidence earlier this year, buying a more than six percent stake in the company. But earlier this month the U.S. automaker said sales had fallen almost 35 percent.

Some economists say Kerkorian stands to lose as much as a half-billion dollars by selling his stake in Ford. Kerkorian's investment company, Tracinda, says it will now focus on the gaming industry and energy.

A growing number of auto industry analysts have expressed concern the global financial crisis could soon overwhelm the major U.S. automakers (Ford, General Motors and Chrysler), once known as the "Big Three."

Economists say the auto industry has been hurt by rising oil prices and the global credit crunch, which has made it difficult for consumers to get loans.

The two other top U.S. auto companies, General Motors and Chrysler, have reportedly entered into talks about a possible merger.

Some information for this report was provided by AFP, AP and Bloomberg.