Long Term Incentive Plan - Listing Application

Costain Group PLC("the Company")

Long Term Incentive Plan - Listing Application

Application has been made for the admission ("Admission") of 500,000 new ordinary shares of 50p each in the Company (the "Shares") to the Official List of the UK Listing Authority and to trading on the London Stock Exchange's market for listed securities.

Admission is subject to the allotment of shares by the Company relating to the vesting of share options that were granted under the Company's Long Term Incentive Plan in March 2015.

The Shares will be issued fully paid and will, upon issue, rank pari passu in all respects with the Company's existing issued shares. Admission, subject to allotment, is expected to occur on 09 March 2018.

06 March 2018