The agency has began the search to exchange Bickerstaff who will stay in his present place till the tip of November.
He steps down at a difficult time for Costain because it battles to revive its share value from round 40p to its degree of round £4 two years in the past.
Final month Costain introduced £92m fist half loss after taking bit hits on the A465 Heads of the Valleys highway contract and the Peterborough & Huntingdon gasoline station job.
Earlier this yr Dubai-based contractor ASGC injected £100m into the enterprise taking a 15% stake..
Dr Paul Golby CBE, chair, stated: “Tony has been with Costain for 14 years and I want to thank him for his vital contribution and private dedication to the Group throughout this time.
“He has been a valued member of the board and we want him each success in his subsequent profession transfer”.
Bickerstaff stated: “I’ve loved my time at Costain and I’m proud to have labored with so many proficient folks. I stay up for my subsequent problem and need the board and my colleagues the easiest for the longer term.”