Thiokol Corp. President U. Edwin Garrison has been elected chairman of the Utah-based aerospace company.

Garrison will continue to hold the posts of president and chief executive officer when he becomes chairman on July 1.Retired Air Force Gen. Robert Marsh, 66, who presently serves as chairman, is stepping down from that position. He will continue to work as a Thiokol director.

Garrison, 63, is an Alabama native who joined the company in 1952 after graduating from Mississippi State University. He first worked for Thiokol's Huntsville, Ala., plant, and then came to Utah in 1958 to join the company's Minuteman ICBM program. In 1964, he became manager of the Minuteman project.