Mitsubishi Materials Corp and Sumitomo Osaka Cement Co announced Thursday that they will jointly develop limestone mines in Kitakyushu.  
 
The two companies will invest approximately 13.5 billion yen to build the mining facility, with Mitsubishi Materials putting up 80% of the money. Construction is scheduled to begin in fiscal 2006, and production of limestone for use in cement will start in 2011.  
 
The companies are developing an undeveloped site that is owned by Sumitomo Osaka Cement and is near a limestone mine that Mitsubishi Materials is currently excavating. By cooperating, the companies can excavate limestone without worrying about boundaries.  
 
The mine is expected to be in full production in 2016, yielding some 7Mt of limestone a year. Mitsubishi Materials will take around 5Mt and Sumitomo Osaka Cement will take the rest. Mitsubishi Materials will ship the limestone to its nearby Kyushu Plant, and Sumitomo Osaka Cement will utilise the harbor facilities at that plant to ship limestone to its plants in Hyogo Prefecture and Kochi Prefecture.