There is an option to extend the seven-year contract by a further seven years worth up to a total value of £730m.
Balfour beat off competition from rival bidders Colas and Ringway Jacobs to land the deal to replace current contractor Costain and Jacobs from May 2023.
Balfour will work alongside East Sussex County Council to maintain the county’s highway network and infrastructure, including roads, pavements, drainage, streetlights, traffic lights and bridges.
The company will also provide winter gritting services and deliver highway improvement schemes.
Steve Helliwell, Managing Director of Balfour Beatty Living Places said: “This latest award builds on our longstanding expertise and commitment to providing best-in-class highways and infrastructure maintenance services across the UK.
“Our dedicated team of professionals will seek to introduce new technologies and innovative solutions wherever we can, helping us to create great places to work, live and play, whilst also leaving behind a lasting positive legacy for the communities in East Sussex.”