Calgon Carbon increased its ownership in the joint venture from 49% to 80% in March 2010 through the redemption of Mitsubishi Chemical shares and changed the name to Calgon Carbon Japan KK. On 31 March 2011 Calgon Carbon completed the acquisition of Calgon Carbon Japan.
In the run up to the transaction, Calgon Carbon negotiated certain claims with Mitsubishi Chemical and the final 20% was acquired without payment of any additional cash.
Calgon Carbon Japan is now a wholly owned subsidiary of Calgon Carbon.