Tokyo Electric Power Co (Tepco) will invest JPY21bn ($254m) for a 12% stake in Thailand's Electricity Generating (Egco) to expand beyond the Japanese market.
Tepco will purchase the stake in the Thai independent power producer through Mitsubishi, which will buy shares from Hong Kong's CLP Holdings and sell a portion to Tepco.
Egco is Thailand's second-largest private power producer after Ratchaburi Electricity Generating Holding.
Egco has interests in 14 power plants in Thailand, Laos and the Philippines with a combined capacity of about 4,277MW accounting for about 12% of the country's generating capacity.
Through the deal, Mitsubishi will increase its interest in Egco to 12.286% from the current 11.21%, at a cost of about JPY2bn ($24m).