Notice of AGM

Costain Group PLC(the "Company")

Notice of 2016 Annual General Meeting and

Annual Report and Accounts for the year ended 31 December 2015

The Company announces that its Annual General Meeting will be held on Thursday 05 May 2016 at 3.00pm at The Lincoln Centre, 18 Lincoln's Inn Fields, London WC2A 3ED (the "2016 Annual General Meeting").

Notice of the 2016 Annual General Meeting (the "2016 AGM Notice") and a form of proxy, together with the Annual Report and Accounts for the year ended 31 December 2015 (the "2015 Annual Report"), will be posted today to those shareholders who have elected to receive paper copies.

The 2016 AGM Notice and 2015 Annual Report will also be available on the Company's website and have been submitted to the National Storage Mechanism, where they will shortly be available for inspection at www.morningstar.co.uk/uk/nsm.aspx.

Additional Information - Disclosure of Home Member State

Pursuant to the requirements of DTR 6.4.2, this is to confirm that, for the purposes of the Transparency Directive Amending Directive (2013/50/EU), the Home Member State of the Company is the United Kingdom.

31 March 2016

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