Peter Sawitz, 69, a retired executive scientist at the Rockville-based ORI Inc., a technical consulting organization, died of a heart ailment Nov. 18 at a clinic in Ixtapa, Mexico. He had been vacationing in Mexico.

Mr. Sawitz, a resident of Bethesda, was a specialist in satellite communications and had served on several U.S. delegations to the World Administrative Radio Conferences of the International Telecommunications Union, an agency of the United Nations.

He was born in what is now East Germany and came to the United States in the mid-1930s. During World War II he served in the Army in Europe. He graduated from Virginia Polytechnic Institute and earned a master's degree in electrical engineering at Ohio State University.

Mr. Sawitz had lived in the Washington area since 1951 and had worked at the Institute for Defense Analyses and served on the engineering faculty at George Washington University before joining ORI in 1970. He retired in 1984.

He was a member of the Montgomery County Association for Retarded Citizens and was president of the Washington chapter of the Friends of Camp Hill, a support organization for retarded persons.

His wife, the former Ilse Adler, died in 1978. Survivors include two sons, Allen, of Roskilde, Denmark, and Eric, of Boston; a daughter, Ina, of Camp Hill, Pa.; a sister, Ilse, of Sale, England, and one granddaughter.