Costain Group PLC

11 May 2023

Trading In Line With Expectations

Costain Group PLC ("Costain" or the "Group") announces it is today holding its Annual General Meeting (AGM).

Alongside the AGM, Costain confirms that it is trading in line with Board expectations. While it is mindful of the
macro-economic backdrop, it remains confident in the Group's strategy and long-term prospects.

As part of the AGM presentation, Costain will provide a short business update drawing on the information published on
14 March 2023. There will be no new material information.

Enquiries

Investors and analysts                                              [email protected]

Paul Sharma, Costain                                                 +44 7867 501188

Financial media - Headland                                    [email protected]

Andy Rivett-Carnac                                                    +44 (0) 7968 997 365

Charlie Twigg                                                             +44 (0) 7946 494 568

Notes to editors

Costain helps to improve people's lives by creating connected, sustainable infrastructure that enables people and the planet to thrive. We shape, create and deliver pioneering solutions that transform the performance of the infrastructure ecosystem across the UK's transport, energy, water, and defence markets.

We are organised around our customers anticipating and solving their challenges and helping to improve performance. By bringing together our unique mix of construction, consulting and digital experts we engineer and deliver sustainable, efficient and practical solutions.