The first industrial plant was constructed by Hiils in 1975 with a capacity of 12000 tonnes per year. Since then, the capacity has been increased to I8000 tonnes per year. The net selectivity (based on C411,) to the trans-trans-cis isomer is 90% with the catalyst system TiCI4 A1(C21 15)Clz AI(C211 5)2CI. Byproducts are cycloocta-l.5-diene, vinylcyclohexene, and butadienc oligo- mers.