Sales of Shares

Costain Group PLC
22 May 2003

                               COSTAIN GROUP PLC

                                 Sale of Shares

Costain Group PLC (the 'Company') announces that it has been notified on 21 May
2003 that one of its major shareholders, Raymond International WLL ('Raymond
International') had sold 1,000,000 ordinary shares in the Company on 16 May 2003
and 500,000 ordinary shares in the Company on 19 May 2003. A spokesman for
Raymond International has advised the Company that these further sales have been
made in order to improve the liquidity in the Company's shares.

Following this notification Raymond International's holding in the Company is
25,993,750 ordinary shares representing 7.53% of the Company's Issued Share
Capital.

                                                                     22 May 2003

Enquiries:

Costain Group PLC                                 Tel: [phone]
Clive L Franks, Company Secretary                 [e-mail]


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