Re: Holding in Company

Tullow Oil PLC
16 June 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 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


 13,570,237   FISL        Chase Nominees Ltd

      499,016    FISL        Chase Manhattan Bank London

      514,000    FPM        Citibank

      271,000    FPM        HSBC

      392,900    FPM        Bank of New York London

   3,302,516   FIL           MSS Nominees Ltd

   1,190,168   FIL           Bank of New York - Brussels

   1,012,833   FIL           Chase Nominees Ltd

      220,848    FIL           Bankers Trust

      467,199    FIL           Bank of Ireland

      172,500    FIL           HSBC Client Holdings Nominee (UK) Limited

      632,300    FIL           Chase Manhattan Bank London

   1,109,681   FIL           Northern Trust

      124,000    FIL           State Street Bank & Trust

   1,624,700   FIL           Bank of New York London

   1,722,500   FIL           Nortrust Nominees Ltd

        65,013    FIL           Deutche Bank

      162,820    FIL           Mellon Nominees Ltd

   1,227,558   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


764,146 since last notification



8. Percentage of issued class


0.12%



9. Class of security


Ordinary 10p shares



10. Date of transaction






11. Date company informed


15 June 2004



12. Total holding following this notification


29,879,589



13. Total percentage holding of issued class following this notification


4.78%



14. Any additional information


Total shares in issue 625,380,144



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


16 June 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