Billionaire investor Kirk Kerkorian has sold his remaining 5 percent stake in Ford Motor Co, according to his investment company, Tracinda Corp.

Kerkorian, 91, has unloaded his last 107 million shares - a 4.89 percent stake - ending his investment with the troubled Dearborn, Michigan, automaker whose turnaround efforts he expressed confidence in earlier this year.

Kerkorian's stake in Ford peaked in June, when he owned 6.49 percent after paying $1 billion at an average share price of $7.10. He began scaling back his ownership in October, selling shares at an average price of $2.43 each, according to regulatory filings. That marked a loss of about two-thirds of his investment, or roughly $650 million.