Exercise of Share Warrant

Costain Group PLC
31 March 2004

Costain Group PLC

Exercise of Share Warrant


Application has been made to the UK Listing Authority and to the London Stock
Exchange for the admission of 7,999,990 ordinary shares of 10p each fully paid
ranking pari passu with the existing ordinary shares, to the Official List and
to trading.

These shares are issued pursuant to a Share Warrant Instrument by way of Deed
Poll dated 29 March 2001 in which the Company's bankers were granted share
warrants in return for re-financing the Company's existing term facilities at
that time. A total of 1,600,000 warrants were issued and each warrant gave the
recipient a right to subscribe for ten ordinary shares at 10p each in the
Company. The exercise price was 112.25p per warrant. Following this exercise no
warrants remain outstanding.

                                                                   31 March 2004


Enquiries:

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


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