Hart Perry, 73, a former International Telephone and Telegraph executive and an organizer of the U.S. Development Loan Fund for Third World countries. Perry was with ITT from 1961 to 1973. He served as executive vice president, chief financial officer and a director. In 1958, he organized the U.S. Development Loan Fund, then the principal source of federal funding for Third World countries and the precursor to the Agency for International Development. In Germantown, N.Y., on Thursday of cancer.