Directorate Change

Costain Group PLC ("Costain", or the "Company") announces Mr Bishoy Azmy is to step down from the Board of Costain with effect from 31 March 2024. Mr Azmy is the designated Board representative of ASGC, a Dubai-based construction conglomerate and 15% shareholder in the Company, and was appointed to the Board as a non-independent non-executive Director in June 2020.

Bishoy Azmy said: "Costain has today announced yet another strong operational and cash performance demonstrating the successful delivery of its strategy and the exciting prospects for the business. I am also delighted that the Board has been significantly strengthened and refreshed with a change in Chair and the recent appointment of two non-executive Directors with excellent, directly relevant experience. I have already seen first-hand the benefits this brings to the Company. It is therefore a natural time for me to step down from the Board to focus on my other global interests. As a shareholder, we remain committed to the future of Costain."

Kate Rock, Chair, Costain said: "Bishoy remains a strong advocate and supporter of Costain as we continue to grow the business and add value for our shareholders. We are very grateful to him for his considerable contribution to the Board during the past four years. I fully understand and appreciate that, as he sees Costain well set for future growth, he now wishes to step down from the Board to commit to his other significant global activities. I am also delighted with the recent appointments of Steve Mogford and Amanda Fisher as independent non-executive Directors who have brought their considerable experience to the Costain Board."

The relationship agreement between ASGC and the Company, which was put in place at the time of the equity raise in May 2020, is unaffected by Mr Azmy stepping down from the Costain Board.