The right-hand man of the financier John Hay Whitney and a pioneering venture capitalist who became an important backer of biotechnology ventures, a New York civic leader and the head of the Federal Government's war on cancer.
Mr. Schmidt came to national prominence in the 1970's, when he was appointed by President Richard M. Nixon to serve as chairman of the President's Cancer Panel. He was also a longtime chairman of the Memorial Sloan-Kettering Cancer Center in New York.
In the 60's, Mr. Schmidt became heavily involved in New York civic affairs, as a trustee of the Whitney Museum of American Art, chairman of the Fund for the City of New York, chairman of the Bedford-Stuyvesant Development and Services Corporation, and later, chairman of Memorial Hospital. As an acknowledged leader in both the private and public sector efforts, he had such a huge influence on the course of medical research and investment that the writer Barry Werth described him in 1994 as ''the senior gatekeeper of biomedical innovation in the United States.''
Mr. Schmidt's survivors include four sons, Benno Jr., Ralph and John, all of New York, and William, of Sarasota, Fla.; three stepchildren, Ruth Fleischmann and Stephen Fleischmann, both of New York, and James, of Philadelphia; 15 grandchildren; and one great-grandchild. A fifth son, Thomas, died in 1966. His second wife, Nancy Montgomery Fleischmann, died earlier this year. His first wife, Martha Chastain, also died this year; their marriage ended in 1962.