Annual Information Update

Costain Group PLC
19 May 2006

Costain Group plc



Annual information Update for the 12 months up to and including 17 May 2006



In accordance with Prospectus Rule 5.2, the Company sets out below a summary of
the information which has been published or made available to the public over
the previous 12 months.



1. RIS Announcements



The following UK regulatory announcements have been made via a Regulatory
Information Service.  A copy of these announcements can be obtained from the
London Stock Exchange website, www.londonstockexchange.com/marketnews.



Date                                          Headline

2 May 2006                               Voting results of AGM

27 Apr 2006                              AGM Statement

24 Apr 2006                              Long-Term Incentive Plan

18 Apr 2006                              2006 Financial Calendar

15 Mar 2006                              Preliminary Results

6 Mar 2006                               Appt of new Finance Director

16 Jan 2006                              BSF Contract Win

11 Jan 2006                              Trading Update

9 Dec 2005                               Consortium for M25 DBFO

16 Nov 2005                              Application for Blocklisting

2 Nov 2005                               Alcaidesa development

12 Oct 2005                              Financial Close 0on Kent PFI

22 Sep 2005                              Director/PDMR Shareholding

20 Sep 2005                              Share Incentives

14 Sep 2005                              Holding(s) in Company

13 Sep 2005                              M1 Road Contract

12 Sep 2005                              Appt. of new Chief Executive

31 Aug 2005                              Interim Results

17 Aug 2005                              Transition to IFRS

12 Aug 2005                              Holding(s) in Company

29 Jul 205                               PFI Scheme Awards

15 Jul 2005                              Major Road Contract Award

13 Jul 2005                              Change in shareholding

1 Jul 2005                               Trading Statement

24 Jun 2005                              Iran Gas Contract

9 Jun 2005                               Bristol Water Partnership

20 May 2005                              Capital Restructuring



2. Documents filed at Companies House



The Company has also made the following filings with Companies House.  Copies of
these documents can be obtained from Companies House, Crown Way, Cardiff CF14
3UZ (by email at [e-mail] or, if you are a registered
user, through Companies House Direct at www.direct.companieshouse.gov.uk ).









Date                                          Description of filing

11 May 2006                              288c - Director's Particulars Changed

18 Apr 2006                              88(2)- Allotment of Shares

10 Apr 2006                              363a - Annual Return (to 28 Feb 2006)

14 Mar 2006                              88(2) - Allotment of Shares

20 Jan 2006                              88(2) - Allotment of Shares

29 Dec 2005                              88(2) - Allotment of Shares

27 Sep 2005                              288a - Director Appointed

27 Sep 2005                              288b - Director Resigned

5 Jul 2005                               MEM/ARTS - Memorandum of Association
                                         / Articles of Association

1 Jul 2005                               Annual Accounts (to 31 Dec 2004)

20 May 2005                              CERT17 - Reduction of Issued Capital &
                                         Share Premium

20 May 2005                              OC - Reduce Cap Cancel Share Premium A/
c

20 May 2005                              RES01 - Special Resolution

18 May 2005                              RES11 - Special Resolution



3. Documents published and sent to shareholders


28 Mar 2006      2005 Annual Report and Accounts
24 Sep 2005      2005 Interim Report and Accounts



In accordance with the provisions of Article 27(3) of the Prospectus Directive
Regulation, it is acknowledged that the information referred to in this update
was up to date at the time the information was published but some of the
information referred to above may now be out of date.



Copies of information released can be obtained from the Company's Registered
Office at:



Costain House

Nicholsons Walk

Maidenhead

Berkshire SL6 1LN



                                                                     19 May 2006



Enquiries:


Costain Group PLC             Tel: [phone]        [e-mail]

Clive L Franks, Company Secretary




                      This information is provided by RNS
            The company news service from the London Stock Exchange