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 This information is provided by RNS The company news service from the London Stock Exchange BDDGGSL

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Tullow Oil (TLW)
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