Frank Tessitor, a retired State Department official whose government service spanned 34 years, died July 2 after a brief illness in Glendora, Calif. He was 70.

Mr. Tessitor was born in Montalenghe, Italy, and grew up in Spokane, Wash.He graduated in 1930 from Washington State University with a bachelor's degree in mechanical engineering.

Mr. Tessitor's government service included two years with the Army Corps of Engineers in Portland, Ore., 16 years with the Bureau of Reclamation in Denver, and 16 years in foreign service with the State Department.

Mr. Tessitor spent five years in Karachi, Pakistan, with the U.S. operations mission.

He came to Washington in 1957, and worked for four years with the International Cooperation Administration where he was Far East operations officer, reviewing programs for Burma, Laos, Cambodia, Vietnam, Indonesia, Korea, the Philippines, and Taiwan.

During 1961-66, Mr. Tessitor served as chief of the public works and engineering divisions for The Agency for International Development in Taiwan and was responsible for the industrial program there.

Mr. Tessitor retired in 1969 after serving three years a deputy assistant for technical advisory support for AID in Vietnam, where he was in charge of economic development.

Mr. Tessitor's professional and social affiliations included Sigma Tau. The American Society for Testing and Materials, and the San Gabriel Valley Symphony Association. He is survived by his wife, Jane, two daughters, Judith Ann Rudd of Wheaton, and Joyce Farnsworth of San Francisco; a son, Douglas, and granddaughters, Marcey and Stacey Tessiter, all of Glendora.