On May 14, 2018, Osaka Gas signed a contract with a subsidiary of Ares EIF Management, a major U.S. infrastructure fund for power generation and transmission, to acquire a 24.3% stake in Kleen Energy Systems, a natural gas thermal power generation business that operates in Connecticut, in the United States. Four Japanese companies (Osaka Gas, Kyushu Electric Power Co., Chugoku Electric Power Co., and Sojitz Corp.) together have majority ownership (81%) of Kleen Energy Systems. The Kleen Energy Plant, which began operation in July 2011, is a 620 MW natural gas-fired power plant in Connecticut.