The BBC's director of factual and learning, John Willis, is leaving the corporation after three years.

One of the most respected executives in British television, Mr Willis, 60, cited the impending "BBC-wide restructure" linked to the Creative Future initiative as the reason for the timing of his retirement from the corporation.

Mr Willis is not thought to have another job to go to but said that, while he was recently appointed external ombudsman for the Guardian newspaper, he intended to continue with a career in broadcasting.

"Now that the organisation is also planning a BBC-wide restructure, I believe this is the right time for me to retire from the BBC, although certainly not from broadcasting," he said.

"The full benefits of the new factual and learning structure are becoming clearer and the division is in good shape for the future. The foundations are very strong and I know that I have left the division a more coherent and creative place than when I arrived.

"For myself, I recently became external ombudsman for the Guardian but I fully intend to continue my main career in broadcasting."

Mr Willis said he was proud of the fantastic programmes he had been responsible for during his time at the BBC, but admitted it had also been a "tough time" overseeing job cuts.

He added that he would be leaving in a couple of months and was already having conversations about things he might do after moving on from the BBC.

Mr Willis's factual and learning is the BBC programming division that has born the brunt of Mr Thompson's cost-cutting regime.

The division was due to lose more than 400 posts in plans Mr Thompson announced towards the end of 2004.

Last month one of Mr Willis's executives, BBC head of documentaries Alan Hayling, left blaming the cuts which involve reducing the number of executive producers working for him from nine to three, with his department's staff reduced from 120 to 70.

Overall the BBC is seeking to cut around a further 2,000 posts in the next 12 months as part of its plan to cut or outsource up to 6,000 jobs to save £355m a year by 2008.

The BBC director general, Mark Thompson, paid tribute to Mr Willis, describing him as "one of the most respected creative leaders in British broadcasting".

"As a member of the executive direction group he has been a key figure in helping shape the direction of the BBC's Creative Future content strategy," Mr Thompson said.

"I am grateful to John for the work he has done in strengthening and simplifying factual and learning. I fully support the changes he and his colleagues have made there.

"We talked about various roles for John as we begin to implement Creative Future but he has decided to take the opportunity to retire from the BBC and pursue other avenues. We all wish him the very best."

Mr Willis began his career as a documentary maker at Yorkshire Television, winning awards for ground-breaking programmes such as Johnny Go Home and Rampton - the Secret Hospital. He later edited the innovative documentary strand First Tuesday.

As Channel 4's controller of factual programmes he created successful new strands including Cutting Edge, True Stories and Secret History. He then became chief executive of United Productions, overseeing a division that made Hornblower and Oliver Twist.

When Granada bought United, Mr Willis was appointed managing director of LWT and United Productions, and in 2001 he won the Royal Television Society gold medal for creative contribution to television.

He then became vice president in charge of national programming at WGBH in Boston, the biggest station in the public service network in the US, before joining the BBC in April 2003.

Mr Willis cited shows including The Secret Policeman and Planet Earth as among his best achievements at the corporation.

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