It would have been much simpler for me to walk out on Tuesday night

Sir Christopher Bland

He told BBC News Online's Forum that it would not have been right for the BBC, if he had left immediately.

"It would have been much simpler for me to walk out on Tuesday night," he told BBC News Online.

"I do not think that would be right for the BBC."

Sir Christopher will replace Sir Iain Vallance as chairman at BT.

"The government need time to recruit and put in place a successor. The BBC needs either a chairman or an acting chairman during that time," said Sir Christopher.

Prime Minister Tony Blair and Culture Secretary Chris Smith have agreed that Sir Christopher can stay on for a few months.

Sir Christopher denied that an impending general election was one of the reasons he had been asked to stay in place.

'Editorial independence'

"The election means that the recruitment of my successor will be drawn out a bit longer," he said.

Greg Dyke thanked Sir Christopher for his firm leadership

He was adamant that the two roles would not force a conflict on interest.

"The BBC editorial independence is sacrosanct," he said earlier.

Peter Mandelson, the Hartlepool MP and former Labour Party communications director, said: "BBC journalists have clear editorial guidelines to work within, regardless of who the governors are."

But Liberal Democrat spokesman Norman Baker argued that Sir Christopher could not hold both posts simultaneously because there was a "clear conflict of interest".

He said: "Sir Christopher Bland can't possibly do two jobs at once.

"It confirms the view that the BBC's board of governors is past its sell-by-date."

Mr Baker said Sir Christopher had to resign as chairman of the BBC board.

'Firm leadership'

Sir Christopher was appointed by John Major as chairman of the BBC in 1996 after a distinguished career in broadcasting.

He is a former chairman of London Weekend Television (LWT) and deputy chairman of the now obsolete Independent Broadcasting Authority (IBA), as well as a former director of ITN and GMTV.

BBC director general Greg Dyke said: "Christopher has been a strong champion and servant of the public interest and the BBC's independence in his stewardship over the last five years.

"I personally, and the BBC generally, are grateful for his firm leadership and wise counsel as chairman of the BBC Board of Governors."

Mr Dyke said it was good news that Sir Christopher would continue until a successor is appointed.

He added: "I wish Christopher well for his new challenge at BT."