DETROIT (AP) — Billionaire investor Kirk Kerkorian, making another attempt to shape the US automotive industry, disclosed yesterday that he had acquired a 4.7-percent stake in Ford Motor Co. and hoped to boost his holdings as the company tries to return to sustained profitability.

Tracinda Corp., Kerkorian's investment company, said it planned to make a $170 million cash offer for up to 20 million additional shares at $8.50 a share, citing evidence that Ford's turnaround plan was working.

Kerkorian's announcement touched off a wave of speculation on how he might try to influence the Dearborn, Mich., automaker in the coming months. The 90-year-old mogul made an unsuccessful bid for Chrysler last year and pushed for General Motors Corp. to form an alliance with Nissan Motor Co. and Renault SA in 2006 after acquiring nearly 10 percent of the company. The Ford family, while owning four percent of the company's shares, has 40-percent voting rights of the company through a special class of stock, making a takeover unlikely, analysts said. Kerkorian could be interested in leaving his imprint on the company's turnaround, putting an ally on Ford's board or advocating for an alliance with another automaker, they said.