The ESB's chief executive, Mr Ken O'Hara, will retire next July, aged 63. He said he would remain in the position until then to facilitate a smooth transfer for his successor. Key tasks he had set himself had been achieved, he said. "I believe the company is in far better shape than it was four years ago when I came into the job."

But Mr O'Hara suffered a number of serious setbacks this year, including the Government's refusal to sanction a €1.4 billion (£1.1 billion) bid for a cluster of eight electricity companies in Poland within hours of the deadline. He also failed to secure board support for a flotation plan and encountered delays delivering a rationalisation programme designed to cut its 8,500 staff by 2,000. In an unexpected move earlier this year, Mr O'Hara hired a private public relations consultant.

Though he is understood to have faced criticism from certain board members at the State electricity company, Mr O'Hara yesterday said that "wasn't something I heard debated at all".

He said: "I see a healthy challenge from the board as part of its role. I'd accept that as its role. I think the board was good at that, mind you. It's a very good board from that point of view." Mr O'Hara said he did not believe a statement by the company's trade unions that criticised "management" was directed at him. "I never felt that that was the case actually," he said.

Asked about the flotation plan he championed, he said: "Clearly at that time a lot of other issues were on our plate."

Mr O'Hara will be 40 years with the ESB in three weeks' time. An engineer, he was appointed chief executive in September 1997, he faced immediate controversy when the Government deferred the Buckley pay deal that would have seen Mr O'Hara earn about £200,000 each year. The company's board eventually backed down and implemented an earlier arrangement, known as the Gleeson guidelines, which restricted his annual pay to about £100,000.

The Minister for Public Enterprise, Ms O'Rourke, paid tribute to Mr O'Hara's "diligence, dedication and skill". "I have always appreciated the hard work and co-operative spirit which the chief executive brought to his job," she said.