Dalkia Ireland has acquired ESB independent subsidiary Ballyragget Power.
Although the price was not disclosed, it is understood to have been under €14 million.
Ballyragget Power has built and operates five combined heat and power plants in the Republic, generating a total of 19MW of power.
Dalkia is a subsidiary of Veolia Environnement and Electricité de France - the firm that operates the Luas through its Veolia Transport Ireland subsidiary - and employs 420 people in Ireland.
The company, which says it has annual revenues of over €58 million, is also involved in banking, pharmaceutical and commercial activities.
