Holding(s) in Company

Tullow Oil PLC
27 May 2005

                                  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 Group 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

                                                    Number            Beneficial
Registered Holder                                of Shares              Interest

Nutraco Nominees                                45,802,629                    No
Limited

Merrill Lynch Pension                            5,637,723                   Yes
Nominees Ltd A/C Noncert

Treasury of the                                  1,477,797                    No
Government of the Isle of Man
Nominees A/C 5

Treasury of the                                    702,946                    No
Government of the Isle of Man
Nominees A/C 10

Stamford Nominees                                  117,100                    No
Limited A/C CHARITY

Other names                                     30,471,274                    No

Total                                           84,209,469



5. Number of shares/amount of stock acquired

Not disclosed



6. Percentage of issued class

Not Disclosed



7. Number of shares / amount of stock disposed

Not Disclosed



8. Percentage of issued class

Not Disclosed



9. Class of security

Ordinary 10p shares



10. Date of transaction

-



11. Date company informed

26 May 2005



12. Total holding following this notification

84,209,469



13. Total percentage holding of issued class following this notification

13.02%



14. Any additional information

Total shares in issue 646,482,128



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

27 May 2005



END


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