Henry Luce III, 80, son of the co-founder of Time magazine and a former publisher of Time and Fortune, died Sept. 8 at his summer home on Fisher's Island, N.Y. The cause of death was cardiac arrest, said Terry Lautz, vice president of the Henry Luce Foundation.

The foundation was established by Mr. Luce's father in 1936. Mr. Luce became its president and chief executive in 1958 and served as chairman from 1990 to 2002, when he became chairman emeritus.

The foundation has assets of approximately $750 million, and its work reflects the interests of the Luce family, including the interdisciplinary exploration of higher education, public policy and the environment, religion and theology, increased understanding between the United States and Asia, American art and women in science.

Mr. Luce, known as "Hank," was born in New York, the elder son of Henry R. Luce and his first wife, Lila Hotz Luce. He served as a naval officer on a destroyer in the Pacific from 1943 to 1946. He received a bachelor's degree from Yale University in 1948 and then went to work as an assistant to Joseph P. Kennedy, at the time a member of the Commission on Organization of the Executive Branch of Government, known as the Hoover Commission.

He worked for two years as a reporter for the Cleveland Press before becoming a Washington correspondent for Time. He also worked in New York as a foreign news and national affairs writer for the magazine.

In 1956, he was named head of the company's New Building Department, which planned and supervised construction of the Time & Life Building at Rockefeller Center. After the building was finished in 1960, he held a number of positions at Time Inc. before being named vice president of the corporation in 1964.

He became London bureau chief of Time-Life News Service in 1966 and then publisher of Fortune in 1968. He became Time's publisher the next year.

In addition to his positions with the family foundation, Mr. Luce was involved with a number of cultural and philanthropic organizations, including the Eisenhower Exchange Fellowships, the New Museum of Contemporary Art, the China Institute in America, the Brooklyn Museum of Art and the Smithsonian American Art Museum.

In 2001, Mr. Luce told United Press International that he was extremely proud of the support the Luce Foundation had given to accessible storage and study facilities at several museums, including the Smithsonian's American Art Museum.

Asked what he himself collected, Mr. Luce said he used to collect 20th century and contemporary art but found that hobby "no longer affordable."

"So I started collecting cast-iron wheeled toys," he told UPI. "I now have more than 60."

His marriage to Patricia Porter Luce ended in divorce. His second wife, Clair McGill Luce, died in 1971; his third wife, Nancy Bryan Cassiday, died in 1987.

Survivors include his wife of 15 years, Leila Eliott Burton Hadley Luce of New York, Fisher's Island and Oyster Bay, N.Y.; two children from the first marriage, Lila Frances Luce of Kenya and H. Christopher "Kit" Luce of New York; and a brother.