Holding in Company

Tullow Oil PLC
14 May 2004

                                  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


        16,200    FMTC     State Street Nominees Ltd.

        14,200    FMTC     Brown Brothers Harriman

          9,500    FMTC     State Street Bank & Trust

15,553,086    FISL        Chase Nominees Ltd

      499,016    FISL        Chase Manhattan Bank London

      424,290    FPM        Chase Nominees Ltd

      158,466    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

   1,377,306   FIL           Bank of New York - Brussels

   1,905,562   FIL           Chase Nominees Ltd

      220,848    FIL           Bankers Trust

      467,199    FIL           Bank of Ireland

   1,443,301   FIL           HSBC Client Holdings Nominee (UK) Limited

      765,747    FIL           Chase Manhattan Bank London

   1,429,878   FIL           Northern Trust

      143,363    FIL           State Street Bank & Trust

   1,721,649   FIL           Bank of New York London

   1,890,058   FIL           Nortrust Nominees Ltd

      134,900    FIL           Deutche Bank

       264,700   FIL           Mellon Nominees Ltd

   1,298,158   FIL           JP Morgan

      729,400    FIL           State Street Nominees Ltd

      868,400    FIL           Morgan Stanley



5. Number of shares / amount of stock acquired






6. Percentage of issued class






7. Number of shares / amount of stock disposed


4,260,274 since last notification



8. Percentage of issued class


1.13%



9. Class of security


Ordinary 10p shares



10. Date of transaction






11. Date company informed


13 May 2004



12. Total holding following this notification


35,815,643



13. Total percentage holding of issued class following this notification


9.48%



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


14 May 2004

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