According to Reuters report indicated that a total of four naphtha crackers in Japan are set to enter scheduled maintenance shutdowns in 2015, down from nine this year. The following table shows manufacturers' nominal ethylene production capacity per year. The manufacturers include oil refiners Idemitsu Kosan Co and JX Nippon Oil & Energy, and Osaka Petrochemical Industries Ltd, a wholly-owned unit of Mitsui Chemicals. Keiyo Ethylene is 55% owned by Maruzen Petrochemical Co and 22.5% each by Mitsui Chemicals and Sumitomo Chemical Co. Asahi Kasei Chemicals Corp is part of Asahi Kasei Corp. Maruzen Petrochemical is 40% owned by Cosmo Oil Co group. Tonen Chemical Corp is part of Tonen General Sekiyu group. Others are Showa Denko, Tosoh Corp and Mitsubishi Chemical Corp.