Park Jun-kyung, the eldest son of Kumho Petrochemical Chairman Park Chan-koo, was promoted to president from senior executive vice president, as part of the company s management succession to the third generation of its owner family, according to the synthetic rubber maker, Friday. With the promotion, the younger Park became president a year and a half after being promoted to senior executive vice president. He is a grandson of the petrochemical company s founder Park In-chon.