U. Edwin Garrison will take over as president and chief executive officer of Thiokol Corp. on July 1.

Following stockholder approval, Morton Thiokol will become just plain Thiokol on July 1 after the company spins off its commercial businesses to stockholders.Charles S. Locke, presently chairman and chief executive officer of Morton Thiokol, was earlier named to head Morton International Inc. After the split, the Locke-led company will include the commercial businesses of specialty chemicals, salt and inflatable airbags.

Garrison, 61, joined the company in 1962, and is currently president of the Aerospace Group of Morton Thiokol and a corporate vice president. In addition, General Robert T. Marsh, a retired Air Force officer, was named chairman of the board for the Thiokol Corp.