Costain Group plc is a British technology based construction and engineering company headquartered in Maidenhead, England. Founded in 1865, its history includes extensive housebuilding and mining activities, but it later focused on civil engineering and commercial construction projects. It was part of the British/French consortium which constructed the Channel Tunnel at the end of the 1980s, and has been involved in Private Finance Initiative projects.

Type:                     Public limited company

Traded as:           LSE: COST

Industry:              Construction, civil engineering

Founded:            1865

Headquarters:   Maidenhead, England, UK

Website:              www.costain.com