A major reorganization in the management of Huntsman Chemical Co., the Salt Lake-based, largest privately held chemical company in the United States, has been announced by Jon M. Huntsman, chairman and chief executive officer.

The major purpose of the reorganization, said a company spokesman, is to create one management team to operate all Huntsman petrochemical-related businesses. Plans to expand the business in North America, the Soviet Union, Asia and other Pacific rim countries, necessitated a management streamlining, Huntsman said.Huntsman named Henry Sullivan as vice chairman of the board of Huntsman Chemical Corp. He previously was president of Huntsman Petrochemical, a subsidiary.

Ronald A. Rasband, president and chief operating officer of Huntsman Chemical, will direct the daily operations of the company's polystyrene, expandable polystyrene, polypropylene and styrene monomer businesses.

Mark Bruner was named executive vice president with headquarters in Chesapeake, Va., with responsibilities for the plastics businesses and research and development.

Tom Wood is senior vice president, international, with responsibility for developing all Huntsman businesses in the world except North America, Europe and the Soviet Union. He will be headquartered in Chesapeake.

Richard Urbanski is a senior vice president for Europe and will oversee the company operation there along with the Soviet Union while working out of the Carrington, England, office.

Brent Turkington is a senior vice president of petrochemicals with responsibility for the purchase, use and sale of styrene monomer, feedstock and raw materials worldwide. He will be located in the Salt Lake office.

Other appointments include Joseph Foster, vice president for polystyrene; Bradford Jones, vice president for polypropylene; Robert Shelker, vice president for expandable polystyrene; Michael Ringwood, vice president-controller; Peter Huntsman, vice president of purchasing; and Michael Eades, vice president for corporate development and special projects.