Open University vice-chancellor Sir John Daniel is to become assistant director general of Unesco, the United Nations' educational and cultural organisation, in Paris.
Sir John said he was looking forward to new challenges, but it would be a wrench to leave the OU. In the ten years he has been there, he has seen student numbers almost double, the student profile broaden, and the OU's worldwide standing grow in all forms of learning.
He said: "I have always felt that if you have not achieved what you set out to do after ten years as vice-chancellor, you never will. I am very proud of what we have achieved, and very pleased to see the OU now powering into the 21st century."
He believes that tuition fees dictated by the market, rather than the government, have played a key part in the university's runaway success. He said: "It is a worldwide lesson that fees plus better student support is a better way of widening access than lowering fees. We now have a broader socioeconomic profile in our student population."
Sir John, who has joint British and Canadian citizenship, said the main challenges facing the OU are maintaining its place in the e-learning market and finding the right balance between global online and local delivery of learning overseas.
"We are long past the one-size-fits-all OU that we started out with," he said.
As assistant director general for education, Sir John will head Unesco's largest programme sector. He will manage 430 staff, more than half of whom are based in developing countries in Africa and Asia, and he will control budgets that total nearly $250 million over two years.
The post has been vacant since Australian academic Colin Power retired in April. Director general Koichiro Matsuuro took his time appointing a permanent successor because he said it was necessary to follow lengthy recruitment procedures that were open and transparent. Before Mr Matsuuro arrived at Unesco, a report revealed corruption, nepotism and cronyism in the organisation, which he promised to root out.
Unesco's priority now is the Education For All programme.