Costain Regulatory News (COST)

Costain Group PLC(the "Company")

Notice of 2020 Annual General Meeting

Further to the Company's announcement on 31 March 2020, the Company announces that its Annual General Meeting will be held on Friday 19 June 2020 at 10.00am at Costain House, Vanwall Business Park, Maidenhead Berkshire SL6 4UB (the "2020 Annual General Meeting").

Notice of the 2020 Annual General Meeting (the "2020 AGM Notice") and a form of proxy will be posted today to those shareholders who have elected to receive paper copies.

The 2020 AGM Notice has been submitted to the National Storage Mechanism, where it will shortly be available for inspection at https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

Due to the Coronavirus pandemic, the UK Government has prohibited public gatherings of more than two people. The 2020 Annual General Meeting will therefore be run as a closed meeting and shareholders will not be able to attend in person. The Company will make arrangements such that the legal requirements to hold the meeting can be satisfied through the attendance of a minimum number of employee shareholders, and the format of the meeting will be purely functional.

The Board recognises the importance of the Company's AGM to shareholders and is keen to ensure that all the Company's shareholders are able to exercise their right to participate in the meeting by voting. Details on how to submit proxies are set out in the 2020 AGM Notice. Given the current restrictions on attendance, shareholders are encouraged to appoint the chair of the meeting as their proxy rather than a named person who will not be permitted to attend the meeting.

Shareholders may also submit questions in advance of the meeting by sending an email to info@costain.com and the Company will answer all such questions in due course.

Given the evolving situation with regard to the Coronavirus pandemic, any changes to the 2020 Annual General Meeting will be communicated to shareholders before the meeting through our website at www.costain.com and, where appropriate, by RIS announcement.

The 2020 AGM Notice and the Annual Report and Accounts for the year ended 31 December 2019 which was published on 2 April 2020 are available on the Company's website at www.costain.com.

18 May 2020

Enquiries:

Peter Hewer