Mark Rogerson, who joined Speedy as chief operating officer in December, has been promoted to chief executive.
Rogerson arrived at the company shortly after the discovery of a £5m hole in it accounts was uncovered – a discovery that led to the resignation of previous chief executive Steve Corcoran.
He joined the company from Costain Group where he was managing director of the natural resources division. Before Costain, he spent eight years leadership roles at Serco Group.
She also paid tribute to Corcoran, who has left the company, saying he had been “at the forefront in the transformation of Speedy” in over 25 years with the company.
Robertson said: “I am very excited to have been offered the opportunity to lead Speedy at a time when our nation’s economy and growth are recovering. Speedy’s breadth of assets, depth of capabilities and the passion of our people will enable us to differentiate our service offering.”