EIRGRID, THE national electricity grid operator, has agreed to buy the transmission system operator SONI in Northern Ireland for £30 million (€37 million).

SONI, which is currently owned by Northern Ireland Electricity (NIE), a part of the Viridian group, was put up for sale as part of an agreement between NIE, the Department of Enterprise, Trade and Investment and the Northern Ireland Authority for Utility Regulation, to further enhance the independence of the grid operator in Northern Ireland.

Eirgrid and SONI are already partners in the Single Electricity Market Operator (SEMO) joint venture, which operates the all-island wholesale single electricity market.

Eirgrid chief executive Dermot Byrne said: "We see this very much as a practical step, building upon the common work which has been going on in relation to electricity markets in each jurisdiction.

"For us and the regulatory authorities, this is about delivering benefits for customers.

"It is based on four elements that EirGrid and SONI share - our functions as transmission system operators carrying out similar work in our respective jurisdictions; our priorities of delivering safe, secure, reliable and economic transmission of power, respectively in the Republic of Ireland and Northern Ireland; quality in the form of both companies' extremely experienced, well trained and qualified staff; and the joint successful operation of the Single Electricity Market."

A spokeswoman for Eirgrid said the deal was a natural fit for the company and represented good value for money.

"It is bringing the advantages of the single electricity market together and allowing Eirgrid and SONI to work closer together and to leverage any of the benefits there are for industrial and domestic consumers," the spokeswoman said.

SONI will continue as an autonomous distinct licensed entity with its existing staff and management team remaining in place.

The sale, which is subject to the approval of the Irish Competition Authority, is scheduled to complete by October 2008.