Tonga's sole power generator, Shoreline, is reported to have signed a preliminary sale agreement with a New Zealand company, Northpower of Whangarei.
The Chief Executive for the Shoreline, Soane Ramanlal, said the agreement was the first step, but there were still a number of conditions to be worked through.
The Matangi Tonga news site says the three parties to the sale, the Government of Tonga, Shoreline Power and Northpower must agree on a regulatory framework.
It's hoped that Northpower will be operating Tonga's electricity generation by early next year.