Director/PDMR Shareholding

13 November 2013

Costain Group PLC

("Costain" or the "Company")

Transaction in shares by a Person Discharging Managerial Responsibility ("PDMR")

The Company received notification on 12 November 2013 that, on 11 November 2013, Mr Michael Alexander, a Non-Executive Director of the Company, purchased 106 ordinary shares of 50p each in the Company at a price of 288p per share (under a dividend re-investment plan through Hargreaves Lansdown Nominees). The transaction was carried out in London.

This announcement is made following a notification made in accordance with Disclosure and Transparency Rule 3.1.2R.

Enquiries:

Costain Group PLC Tel: 01628 842444Tracey Wood, Company Secretary

College Hill Tel: 020 7457 2020Mark GarrawayHelen Tarbet