THE ESB has been given the green light to slash the cost of its electricity bills for residential customers from next month.
The energy regulator said that the State-owned electricity supply company would not have to refer to the Commission for Energy Regulation (CER) before it raises or reduces prices.
CER chairperson Michael Tutty said deregulation of prices would assist in providing additional choices and competitive prices for consumers.
The decision comes as more than one million electricity customers have switched suppliers since the market opened up to competition in 2009.
Customer-switching rates in Ireland were among the highest in Europe as thousands migrated to alternative suppliers, but the CER required ESB's market share to fall to 60pc by early next year before it allowed deregulation to begin.
ESB prices are fixed by the regulator to stop it undercutting new competitors trying to get a toehold in the market.
The new ESB name -- Electric Ireland -- has been applied to its electricity supply arm, to differentiate it from ESB networks which would continue to provide the wires connecting homes to the national grid, regardless of which supplier is used.