Re: Holding in Company

Tullow Oil PLC
26 March 2004

                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of company


Tullow Oil plc



2. Name of shareholder having a major interest


Merrill Lynch Investment Managers Limited



3. Please state whether notification indicates that it is in respect of holding
of the shareholder named in 2 above or in respect of a non-beneficial interest
or in the case of an individual holder if it is a holding of that person's
spouse or children under the age of 18


See 4 below



4. Name of the registered holder(s) and, if more than one holder, the number of
shares held by each of them


   Registered Holder                                 Number of               Beneficial

                                                                    of shares                 Interests?

                                                                                                     (Yes/No)



Nutraco Nominees Limited                     31,706,997              No

(designated and undesignated)

Merrill Lynch Pension Nominees Ltd        5,262,070             Yes

A/C NONCERT

Treasury of the Government of                     621,397             No

Isle of Man A/C5

Treasury  of the Government  of                   287,946             No

Isle of Man A/C 10

Chase Nominees Limited                         5,797,570             No

Nortrust Nominees Limited                       2,988,081             No

Bank of New York Nominees Limited      1,908,933             No

Morgan Nominees Limited                           985,586             No

Other names                                               4,309,753             No



5. Number of shares / amount of stock acquired


8,404,533 since last notification



6. Percentage of issued class


2.22%



7. Number of shares / amount of stock disposed






8. Percentage of issued class






9. Class of security


Ordinary 10p shares



10. Date of transaction






11. Date company informed


26 March 2004



12. Total holding following this notification


53,868,333



13. Total percentage holding of issued class following this notification


14.25%



14. Any additional information


Total shares in issue 377,841,915



15. Name of contact and telephone number for queries


Tom Hickey  0207 333 6800



16. Name and signature of authorised company official responsible for making
this notification


Tom Hickey



Date of notification


26 March 2004



The FSA does not give any express or implied warranty as to the accuracy of this
document or material and does not accept any liability for error or omission.
The FSA is not liable for any damages (including, without limitation, damages
for loss of business or loss of profits) arising in contract, tort or otherwise
from the use of or inability to use this document, or any material contained in
it, or from any action or decision taken as a result of using this document or
any such material.





                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of company


Tullow Oil plc



2. Name of shareholder having a major interest


FMR Corp and its direct and indirect subsidiaries and Fidelity International Limited (FIL) and its direct and indirect
subsidiaries.



3. Please state whether notification indicates that it is in respect of holding
of the shareholder named in 2 above or in respect of a non-beneficial interest
or in the case of an individual holder if it is a holding of that person's
spouse or children under the age of 18


Notification relates to above-named shareholders' non-beneficial interests held through direct and indirect
subsidiaries including: Fidelity Management Trust Company (FMTC): Fidelity Investment Services Ltd (FISL) and Fidelity
Pension Management (FPM). The notifiable interests also comprise the notifiable interest  of Edward C. Johnson 3d, a
principal shareholder of FMR Corp. and Fidelity International  Limited



4. Name of the registered holder(s) and, if more than one holder, the number of
shares held by each of them


        18,500    FMTC     State Street Nominees Ltd.

        14,200    FMTC     Brown Brothers Harriman

          9,500    FMTC     State Street Bank & Trust

17,213,622    FISL        Chase Nominees Ltd

      638,338    FISL        Chase Manhattan Bank London

   1,310,000   FPM        Chase Nominees Ltd

      379,900    FPM        Northern Trust

      514,000    FPM        Citibank

      271,000    FPM        HSBC

      392,900    FPM        Bank of New York London

   3,302,516   FIL           MSS Nominees Ltd

   1,462,197   FIL           Bank of New York - Brussels

   3,228,001   FIL           Chase Nominees Ltd

      220,848    FIL           Bankers Trust

      467,199    FIL           Bank of Ireland

        60,400    FIL           Brown Brothers Harriman Ltd. LUX

   3,853,992   FIL           HSBC Client Holdings Nominee (UK) Limited

      955,100    FIL           Chase Manhattan Bank London

   1,696,100   FIL           Northern Trust

      179,700    FIL           State Street Bank & Trust

   1,987,800   FIL           Bank of New York London

   2,315,600   FIL           Nortrust Nominees Ltd

      123,100    FIL           Deutche Bank

        92,200    FIL           Mellon Nominees Ltd

   1,298,158   FIL           JP Morgan

      729,400    FIL           State Street Nominees Ltd

      868,400    FIL           Morgan Stanley

        32,591    FIL           Deutsche Bank AG, London



5. Number of shares / amount of stock acquired






6. Percentage of issued class






7. Number of shares / amount of stock disposed


8,981,129 since last notification



8. Percentage of issued class


2.38%



9. Class of security


Ordinary 10p shares



10. Date of transaction






11. Date company informed


25 March 2004



12. Total holding following this notification


43,635,362



13. Total percentage holding of issued class following this notification


11.55%



14. Any additional information


Total shares in issue 377,841,915



15. Name of contact and telephone number for queries


Tom Hickey  0207 333 6800



16. Name and signature of authorised company official responsible for making
this notification


Tom Hickey



Date of notification


26 March 2004



The FSA does not give any express or implied warranty as to the accuracy of this
document or material and does not accept any liability for error or omission.
The FSA is not liable for any damages (including, without limitation, damages
for loss of business or loss of profits) arising in contract, tort or otherwise
from the use of or inability to use this document, or any material contained in
it, or from any action or decision taken as a result of using this document or
any such material.








This announcement has been issued through the Companies Announcement Service of

The Irish Stock Exchange











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