Re: Holding in Company

Tullow Oil PLC
26 September 2003

                                  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 subsidiaries and Fidelity International and 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


4. Name of the registered holder(s) and, if more than one holder, the number of
shares held by each of them

Chase Nominees Ltd- 26,627,989
Chase Manhattan Bank London - 2,526,704
MSS Nominees - 3,393,416
Northern Trust - 3,576,364
Other - 9,425,213


5. Number of shares / amount of stock acquired




6. Percentage of issued class




7. Number of shares / amount of stock disposed




8. Percentage of issued class




9. Class of security

10p Ord Stock


10. Date of transaction

n/a


11. Date company informed

25/9/03


12. Total holding following this notification

45,549,595


13. Total percentage holding of issued class following this notification

12.04%


14. Any additional information




15. Name of contact and telephone number for queries

Tom Hickey
Tel: [phone]


16. Name and signature of authorised company official responsible for making
this notification

Tom Hickey


Date of notification

26/9/03


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              XDGGXL