Re: Holding in Company

Tullow Oil PLC
07 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


FRM 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 interest also comprises the notifiable interest of Edward C. Johnson 3d, a
principal shareholder of FRM 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

16,552,622 FISL Chase Nominees Ltd

638,338 FISL Chase Manhattan Bank London

942,516 FPM Chase Nominees Ltd

292,189 FPM Northern Trust

514,000 FPM Citibank

271,000 FPM HSBC

392,900 FPM Bank of New York London

2,587,309 FIL MSS Nominees Ltd

1,431,657 FIL Bank of New York-Brussels

2,648,736 FIL Chase Nominees Ltd

220,848 FIL Bankers Trust

467,199 FIL Bank of Ireland

3,373,208 FIL HSBC Client Holdings Nominees (UK) Limited

878,356 FIL Chase Manhattan Bank London

1,605,220 FIL Northern Trust

159,700 FIL State Street Bank & Trust

1,852,384 FIL Bank of New York London

2,094,277 FIL Northern Nominees Ltd

123,100 FIL Deutsche 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




5. Number of shares / amount of stock acquired






6. Percentage of issued class






7. Number of shares / amount of stock disposed


3,559,445 since last notification



8. Percentage of issued class


0.94%



9. Class of security


Ordinary 10p shares



10. Date of transaction






11. Date company informed


6 May 2004



12. Total holding following this notification


40,075,917



13. Total percentage holding of issued class following this notification


10.61%



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


7 May 2004









This announcement has been issued through the Companies Announcement Service of

                           the Irish Stock Exchange.








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