Sir Robert Horton, the abrasive and ambitious chairman of Railtrack, last night stunned the industry and his colleagues by announcing that he would be quitting his £180,000-a-year job by the summer.
Railtrack sources believe his departure follows defeat in a power battle with chief executive Gerald Corbett. A Railtrack source said: "Quite simply, there has been a battle at the top. Corbett has won and Sir Robert has lost. Bob took his eye off the ball and Corbett just nipped through."
A Railtrack announcement said he told the board last month he had wanted to retire after his 60th birthday in August, but that he would stay until a successor was found.
Sir Robert, who has turned Railtrack into a leading FTSE 100 company since it was floated three years ago, said: "It seemed an opportune time to step down from Railtrack. It has been extremely exciting, and I have thoroughly enjoyed the past seven years transforming the company from a public sector entity to a growing vibrant business."
Railtrack made it clear that the successor for his three-day-a-week job will come from outside the industry, which rules out Mr Corbett.
Some Railtrack bosses said they were not surprised at Sir Robert's departure, and that they had only been forced to announce it because headhunters had revealed they were looking for his successor.
But the timing of his departure is significant. The company has to contend with new rail regulator Sir Alistair Morton, who has just been appointed by the Government to head the prospective Strategic Rail Authority.
Railtrack insiders said one of his reasons for quitting was that Sir Robert and Mr Corbett had an increasingly frosty relationship.
Sir Robert did not agree with Mr Corbett's criticism of the rail operating companies for the failure of the industry. Sir Robert preferred a more moderate stance and has left much of the running to Mr Corbett in recent months.
Sir Robert is also said to recognise that tougher times lie ahead for Railtrack. It has been heavily criticised by the Government for not investing fast enough in the industry, even though it is committed to pour £17 billion into it over the next 10 years.
It is about to face tough negotiations with the rail regulator - who is expected to trim its profits. He will tell Railtrack that since it relies for much of its income from the taxpayer it must take more account of the public good than its shareholders.
Sir Robert believes that he has achieved much at Railtrack. Politically, it is more on side with the Government than it was three years ago, when at one stage Labour in opposition threatened to re-nationalise the company when it came to power.
After an uneasy start he has struck up a reasonable relationship with the Deputy Prime Minister, John Prescott. Sir Robert did the Government a favour by saving the Channel Tunnel rail link project, which went belly-up last year, and his company has been in the forefront of the public-private partnership bidding for the London Underground project. But it recently put the project back by saying that it was only interested in the sub-surface lines.
