Billionaire investor Kirk Kerkorian reportedly divests his remaining shares in Ford Motor Co., a seemingly peculiar move given claims from the auto maker its business should improve as early as the middle of next year.

The Wall Street Journal reports Kerkorian sold about 133.5 million shares of Ford sometime after October, when he parted with 7.3 million shares of the auto maker’s common stock and signaled he may sell the rest. The Journal notes another business majority held by Kerkorian’s Tracinda Corp., gaming company MGM Mirage, has been suffering through the economic crisis.

Ford last week said it did not expect to tap federal loans to survive the downturn, as its cross-town rivals General Motors Corp. and Chrysler LLC must do, and that the economy would bottom out in mid-2009 and begin to show gradual improvement.

Ford CEO Alan Mulally told the Detroit Free Press last week that Wall Street analysts have been too pessimistic about the auto maker in recent months.

Prior to the industry’s severe downturn this year, Kerkorian rallied enthusiasm for Ford’s business, announcing he had bought 100 million shares. He added to the investment in June, despite rising gasoline prices, to become Ford’s largest outside investor.

Kerkorian’s activist investment history in the auto industry reaches back to an unsuccessful takeover bid for the former Chrysler Corp. in 1995. He also unsuccessfully sued over DaimlerAG’s purchase of Chrysler in 1998, saying investors were misled by the German auto maker.

In 2005, Kerkorian took a significant position in GM. After placing one of his top advisers on the GM board, Kerkorian dumped his shares after unsuccessfully pressuring the auto maker into a tie-up with alliance partners Renault SA and Nissan Motor Co. Ltd.