Minister for Energy Pat Rabbitte expects Bord Gais to start the sale of its energy unit, comprising retail and power generation, "in the coming weeks."

An information memorandum on the business will be issued to interested parties to formally begin the process, Mr Rabbitte said in an emailed response to questions.

GDF Suez SA, France's largest utility by market value, Centrica and E.ON SE may bid for the unit.

Bord Gais Energy is said to be valued at as much as €1.4 billion.

Royal Bank of Canada is advising Bord Gais on the sale, while Royal Bank of Scotland is counselling on the reorganisation of the group's capital structures, including €2.2 billion of debt.

Barclays is advising the State on the transaction.