Blocklisting Interim Review

Tullow Oil PLC
08 May 2006

                        BLOCKLISTING SIX MONTHLY RETURN



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



To:  The FSA

     The Irish Stock Exchange



Date: 8 May 2006



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 November 2005                            To:    4 May 2006



4. Balance under scheme from previous return:


   2,452,734 ordinary shares of 10p each split



   953,549 - 1988 Scheme

   851,361 - 1998 Scheme
   647,824 - 2000 Scheme



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


   4,859,893 ordinary shares of 10p each split



     859,883 - 1988 Scheme

   1,000,000 - 1998 Scheme

   3,000,000 - 2000 Scheme



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



   1,651,311 ordinary shares of 10p each split


    639,360 - 1988 Scheme

    200,000 - 1998 Scheme

    811,951 - 2000 Scheme



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



   5,681,306 ordinary shares of


 1,174,072 - 1988 Scheme

 1,651,361 - 1998 Scheme

   2,835,873 - 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

   4,859,883 ordinary shares of 10p each admitted on 30 November 2006



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


   648,862,384




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








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