The original contract started in 2011 with May Gurney and transferred to Kier following its acquisition of the company in July 2013.
The extension will run from April 2017 to March 2021.
The scope of work, which includes highways maintenance and improvements, will be expanded to develop a Surrey Highways skill centre to provide a range of training and apprenticeship opportunities.
Haydn Mursell, Kier’s chief executive, said: “Kier has forged a strong working relationship with Surrey Country Council over the past five years.
“This contract reinforces Kier’s presence in the local authority market and further demonstrates the benefits of recent acquisitions, which have strengthened the Group’s highways services and maintenance offering and helped to establish Kier as the market leader in this sector.”