Treasury chief Sir Andrew Turnbull has been appointed as the successor to Sir Richard Wilson as cabinet secretary.

Sir Andrew, who is said to have impressed Tony Blair with his commitment to public service reform, takes over the top civil service role in September.

"Sir Andrew Turnbull is someone of great ability with a track record of delivery and achievement," said the prime minister. "These are demanding times for civil servants with an ever-increasing focus on public service delivery."

Seen as down to earth and a safe pair of hands, Sir Andrew, 57, will do a three-year term before retiring soon after his 60th birthday.

He is said to be relatively unconcerned at the rise of the special adviser in Whitehall - but may have to put together a comprehensive civil service bill to define the boundaries between political appointees and civil servants.

Sir Andrew will become the highest paid public servant, with a salary of £245,000.

He fought off competition from senior mandarins, including Sir Richard Wilson's favoured successor Sir David Omand, the Home Office chief.

The FDA, the trade union representing senior civil servants, welcomed the announcement.

Jonathan Baume, FDA general secretary, said: "Sir Andrew is a highly capable and well respected civil servant who will be able to take forward civil service reform on the basis of more than thirty year's experience in the civil service.

"Most of his career has been in the Treasury but his work as permanent secretary in the environment department will help ensure that his agenda is not just shaped through a Treasury prism."

Mark Serwotka, general secretary of the Public and Commercial Services Union, also welcomed the announcement of Sir Andrew's appointment.

"I personally welcome Sir Andrew to the post and hope that he can build on the good work of his predecessor," he said.

"I am pleased that such an important position has gone to a well established civil servant who understands the way Whitehall works."