The contract has already run for seven years and will now continue until 2020. Amey said that it was worth more than £35m a year.
Amey will provide 24-hour emergency cover for any incidents on the road network as well as investment in the highways infrastructure.
Kent County Council cabinet member for highways Mike Whiting said: “Amey has been a long-time contractor and this extension will see that partnership continue. This is the largest single contract within the highways department, covering a range of services from road repairs to gritting.”
James Haluch, managing director of Amey’s highways business, said: “We are thrilled that Kent County Council has extended the highways contract for a further two years. Since Amey acquired the contract both parties have worked tirelessly to ensure that the contract is delivering and is of mutual benefit to all concerned.
“This two-year extension shows the confidence and trust that Kent County Council have in Amey to deliver excellent service. The additional extension will enable us to further strengthen our local knowledge, and continue our investment in local infrastructure to benefit local people and their communities.”