The chief executive of Partnerships for Schools will leave at the end of this month, ending a five-year stint at the quango.

It is understood his new company, called Cornerstone, has backing from John McDonough of Carillion and Capital founder Rod Aldridge, who also runs academy sponsor the Aldridge Foundation.

Tim Byles said: “I have always believed in the value of delivering public services using the disciplines of the private sector and I look forward to developing that principle in my next venture, that will bring together the very best of the private, public and third sectors in a new breed of social investment company.

“Meanwhile I believe that the secretary of state and his departmental colleagues will deliver an exciting and much-needed programme of free schools and new academies.“

Michael Grabiner, chairman of the PfS board said: “Tim Byles has made an outstanding contribution to the delivery of education capital investment in this country, establishing a track record as someone whose core focus is to get the job done.

“Over the past five years, he has impressed me and the PfS Board with his ability to delivery very challenging tasks in a complex and demanding environment.

“Tim has shown himself to be an individual of the highest integrity and both I and the Board wish him every success in the future.”

Byles announced his exit just days after kicking the academies programme back into gear after a thorough review bent on delivering better value for money.

Of the 75 academy projects placed under scrutiny, Byles let 71 go through in either full or rescoped form in a £800m programme sorely needed by work-starved contractors.

Byles also was widely credited with getting the Building School for the Future programme back on track after being hit by serious delays several years ago.

But the recent James Review into school building in the UK raised a question mark about the future role of PfS. The Review called for a new body with more far-reaching powers than PfS that would manage school building centrally as a means of driving down costs.

The Government has still to respond to these recommendations.