Blocklisting Interim Review

Tullow Oil PLC
07 November 2005

                        BLOCKLISTING SIX MONTHLY RETURN



Information provided on this form must be typed or printed electronically.



To:  The FSA

     The Irish Stock Exchange



Date: 7 November 2005



1. Name of applicant:



   Tullow Oil plc


2. Name of schemes



   Tullow Oil 1988 Executive Share Option Scheme ('1988 Scheme')

   Tullow Oil 1998 Executive Share Option Scheme ('1998 Scheme')
   Tullow Oil 2000 Executive Share Option Scheme ('2000 Scheme')




3. Period of return:


From:     5 May 2005                                 To:    4 November 2005



4. Balance under scheme from previous return:


   3,233,939 ordinary shares of 10p each



5. The amount by which the block scheme has been increased, if the scheme has
been increased since the date of the last return


   N/A



6. Number of securities issued/allotted under scheme during period:


    255,000 - 1988 Scheme

     97,800 - 1998 Scheme

    428,405 - 2000 Scheme



7 Balance under scheme not yet issued/allotted at end of period


 953,549 - 1988 Scheme

 851,361 - 1998 Scheme

   647,824 - 2000 Scheme



8. Number and class of securities originally listed and the date of  admission


2,200,000 ordinary shares of 10p each admitted on 5 November 2003

1,700,000 ordinary shares of 10p each admitted on 9 June 2004

5,000,000 ordinary shares of 10p each admitted on 11 October 2004



9. Total number of securities in issue at the end of the period


   647,211,073




Name of contact:



Richard Taylor


Address of contact



3rd Floor Building 11

Chiswick Park

566 Chiswick High Road

London W4 5YS


Telephone number of contact 0208 996
1000



Signed by ...Richard Taylor

Director/company secretary/suitably experienced employee/duly authorised
officer, for and on behalf of



Name of applicant ...Tullow Oil plc



If you knowingly or recklessly give false or misleading information you may be
liable to prosecution.







This announcement has been issued through the Companies Announcement Service of

                           the Irish Stock Exchange.










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