No successor was immediately named.
"Known for his ability to develop and articulate business strategy, Ernie has left his mark on several of our businesses," said Charles E. Bunch, PPG president and chief operating officer.
"Ernie has not only contributed through business leadership, but also through people leadership. He has been consistent in his advocacy for people development and has served as mentor to many."
Hahn, 60, joined PPG in 1966 at the Springdale, Pa., coatings research and development center. After four years as technical manager of a former Illinois-based subsidiary, he returned to Pittsburgh in 1974 as coatings commercial development manager, and then joined the international coatings department.
Hahn went to Paris in 1978 as director of European coatings operations. He moved to Troy, Mich., in 1981 as assistant general manager of automotive refinishes, was that unit's general manager, and returned to Pittsburgh in 1987 as director of coatings planning and development. He was appointed general manager of industrial coatings in 1990, and became vice president of that unit in 1992.
He moved to his current post in 1996. Hahn received a chemistry degree from Duquesne University and a master's degree in business administration from the University of Pittsburgh. He is a member of the Society of Automotive Engineers.
Pittsburgh-based PPG Industries is a global supplier of coatings, glass, fiber glass and chemicals, with 120 manufacturing facilities and equity affiliates in 23 countries. Sales were US$8.2 billion in 2001