Northern Ireland electricity supplier Viridian has accepted a £1.6bn ($3bn) bid from ElectricInvest, a division of a Bahrain-based private equity company.
NIE supplies 775,000 homes with electricity
ElectricInvest said Viridian, which owns Northern Ireland Electric (NIE), Energia and Powerteam, offered a chance for "stable returns".
Viridian said it considered the bid terms to be "fair and reasonable".
ElectricInvest is part of Arcapita, which already has a stake in several UK utility projects.
These include a partnership with Npower to operate 19 wind farms. It also runs the South Staffordshire water company.
NIE is the main supplier of power to homes in Northern Ireland, while Energia supplies businesses and also runs the Huntsdown power station near Dublin.
News of the bid sent shares in Viridian up 9% on Friday morning.