By MIREYA NAVARRO

MIAMI -- Jorge Mas Canosa, the Cuban-American businessman and political stalwart who died Sunday, was mourned as an irreplaceable figure in the fight for the democratization of Cuba, but officials of his Cuban-American National Foundation vowed to double their efforts to accomplish his goals.

"For those concerned about the future of the Cuban-American National Foundation, don't be concerned," a teary-eyed Francisco Hernandez, the foundation's president, said at a news conference.

"This institution counts on men and women who were close to Jorge Mas Canosa from the beginning and were nurtured by his thoughts and his bravery," he said.

But the death of Mas is a significant blow to the hard-line majority in the exile leadership, in no small part because it is a strong reminder that Fidel Castro is still in power in Cuba after 38 years, outliving many of his opponents.

Mas, in fact, was among the youngest in the old guard of anti-dialogue, anti-Castro conservative leaders, and certainly much younger than Castro, 71, and his brother Raul, 67, the revolutionary leader's anointed successor.

The death of Mas, who assembled a political and economic empire in exile, also leaves Cuba without a favorite target of blame for the island's difficulties. Most recently, the government in Havana had blamed Mas' Cuban-American National Foundation for a string of bomb explosions in Havana's hotels and other tourist spots.

Foundation leaders announced that Alberto Hernandez, the vice chairman and a member of the organization for 15 years, would take over the chairmanship until elections take place in July.

Allies in the Cuban exile cause, like Sen. Robert Torricelli, D-N.J., predicted a difficult transition but said that Mas had left the exile community more united, organized and powerful than it was when the foundation was formed in 1981, including likeminded Cuban-Americans as members of Congress.

"If Fidel Castro takes some comfort in the passing of Jorge Mas Canosa, he's very mistaken," Torricelli said. "At some point the movement for Cuban freedom became larger than the man and is now irreversible."

Although Mas' son, Jorge Mas Jr., 34, has taken over the family's telecommunications business, it is less clear who will succeed him in the political arena. Polls have shown that the elder Mas' public approval rating, particularly among older Cuban-Americans, was unparalleled, as was the combination of his vast economic resources with political power.

Max Castro, a sociologist with the University of Miami's North-South Center and a critic of Mas, said, "He was able to create an organization that was the only Cuban-American organization to insert itself into the structure of American political power.

"I have to recognize that he was effective," he continued. "The problem was how that power was exercised, and in my view the policies he pursued were not effective in bringing democracy to Cuba, and aggravated the suffering of the Cuban people."

Experts on Cuban-American affairs say that Cuban-American elected officials like Ileana Ros-Lehtinen, a Republican member of Congress from Miami, are likely to increase their roles as spokesmen. Political moderates, too, may find an opening to assume greater influence in advocating a more conciliatory stance toward Cuba, such as lifting the U.S. economic embargo and normalizing relations with the island.

One of these moderate leaders, Eloy Gutierrez Menoyo, founder of the exile group Cambio Cubano, or Cuban Change, on Sunday called Mas "a dynamic leader and organizer of proven intelligence" whom he would have liked to debate "in a politically civilized climate," which he said Miami lacked.

In a written statement, he called for Cubans to restore the tolerance "that would allow us to disagree without hate."