DETROIT — After watching Ford's stock climb to a five-year high, a United Auto Workers trust fund is cashing in, selling the rights to an 11 percent ownership stake in Ford to raise at least $1.3 billion for retiree health care.

More than 200,000 Ford retirees and their spouses depend on the trust fund for their health care coverage. While the trust could have waited to see if Ford's shares climb higher, it would be yet another risk in an already turbulent industry. Some analysts say that even with the extra $1.3 billion, the trust is in danger of running out of cash.

The union-run trust began paying health care costs for Ford's retired factory workers and their spouses in January after the company transferred to it cash and other assets valued at $14.8 billion. The fund will auction one of those assets, warrants to buy 362 million shares, starting today. Warrants, like stock options, give the holder a right to buy shares.

Ford's shares dropped 29 cents, or 2 percent, to $13.57 in Monday afternoon trading. But after falling to as low as $1.26 in November 2008, Ford shares have grown more than 10 times in value as the company avoided bankruptcy protection and government aid, won accolades for its vehicle quality and reported a full-year profit for 2009.

On March 18, Ford's shares hit an intraday price of $14.54, the highest level since January 2005. Shelly Lombard, credit analyst at the New York bond research firm GimmeCredit, said the trust is wise to sell the warrants now.