Kansai Electric Power Co. will build a large coal-fired power plant in Chiba Prefecture jointly with major oil firm TonenGeneral Sekiyu K.K., in a foray into the capital region made possible by market liberalization next April, sources familiar with the matter said Sunday.

The 1,000 megawatt plant, almost equivalent in output to a nuclear reactor, will be built adjacent to a TonenGeneral refinery in Ichihara, the sources said. The plant is expected to come online in the mid-2020s and will cost hundreds of billion yen.

Through its subsidiary Kanden Energy Solution Co., the Osaka-based utility will set up a company with TonenGeneral to oversee the project, the sources said.