ROME, May 28 -- Umberto Agnelli, 69, chairman of the troubled Fiat auto empire, died late Thursday, leaving the company that has been the core of Italian industry for more than a century with no designated heir and an uncertain future.

Agnelli's battle with lymphatic cancer became public only this month after a report in the Financial Times.

His death followed by 16 months that of his older and more illustrious brother Giovanni (known as Gianni), who was long regarded as the personification of a classy style of Italian family entrepreneurship.

Long kept outside of the core auto business, Umberto made his re-entry as president of Fiat auto at the request of his ailing brother, he said in interviews. After Gianni's death in January of 2003, Umberto took over the entire Fiat empire and quickly decided to divest some of its peripheral interests.

The decision proved to be a winning one, and with the help of chief executive Giuseppe Morchio, Fiat has begun to cut its losses.

Gianni Agnelli had designated his grandson John Elkann as the eventual heir to the Fiat leadership, but at 28 he is considered by most industry analysts as too green to take the helm.

It wouldn't be the first time in Fiat history that older managers have taken over while heirs have time to ripen. Gianni's and Umberto's father died before they were old enough to run the company; an outsider took over until Gianni came of age in the 1960s.

Auto industry expert Patrizio Bianchi, professor of industrial economics and dean of the University of Ferrara, said in a telephone interview that "the salvation of Fiat will be the separation of the ownership from the management."

Chief executive Morchio is a good manager, Bianchi said, and the family should step aside for a while to let him continue to improve the company's finances. Bianchi credited Umberto Agnelli with "creating the conditions to allow the company to improve" and allowing Morchio to handle day-to-day management.

Umberto's emphasis on the auto business, founded by his grandfather in 1899, surprised many because he had been intent on diversifying the family portfolio for years. Fiat properties included stakes in Club Mediterranee, aerospace, telecommunications and food processing.

As managing director and then vice-chairman with his brother, Umberto always played second fiddle. Gianni, 13 years his senior, was as known for his jet-setting ways as for his business acumen. Umberto kept out of the limelight, but worked at the family companies that control Fiat.

In March 2000, Gianni Agnelli sold 20 percent of Fiat to General Motors Corp. for $2.4 billion, with the option of selling the remainder in 2005. But that cash infusion was not enough to stop the losses.

When Umberto took over, he convinced the family to come up with an additional $250 million, focused on the auto sector. "Umberto's was a strong solution; he put cars first, the symbol of the family ownership," Bianchi said.

Umberto, like his brother and much of the rest of the family , was a fervent supporter of Turin's Juventus soccer team, which is controlled by Fiat and has won more Italian championships than any other. For years he served as president of the team and became president of the Italian soccer league at an early age.

On Friday, the iron gates of Agnelli's villa, La Mandria, on the outskirts of Turin, opened frequently for cars bearing Fiat executives and politicians arriving to give condolences to his wife Allegra and surviving son and daughter. Private funeral services are to be held Saturday at Villar Perosa, the estate of the late Gianni Agnelli.

Umberto Agnelli was Fiat's chairman for only 16 months after succeeding his older and more illustrious older brother, Giovanni.