Re: Holding in Company

Tullow Oil PLC 18 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 Wellington Management Company, LLP 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 Notifiable Interest of Wellington Management Company, LLP 4. Name of the registered holder(s) and, if more than one holder, the number of shares held by each of them Not stated 5. Number of shares / amount of stock acquired 5,128,700 since last notification 6. Percentage of issued class 1.36% 7. Number of shares / amount of stock disposed N/A 8. Percentage of issued class N/A 9. Class of security Ordinary 10p shares 10. Date of transaction Not Known 11. Date company informed 17 May 2004 12. Total holding following this notification 17,240,100 13. Total percentage holding of issued class following this notification 4.56% 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 18 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

Companies

Tullow Oil (TLW)
UK 100