Holding In Company

Tullow Oil PLC
13 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


Legal & General  Group plc and/or subsidiaires



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


As 2 above



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


 HSBC Global Custody Nominee (UK) Ltd A/C 914945        181,379

 HSBC Global Custody Nominee (UK) Ltd A/C 923363        524,000

 HSBC Global Custody Nominee (UK) Ltd A/C 775245     2,177,674

 HSBC Global Custody Nominee (UK) Ltd A/C 130007        327,000

 HSBC Global Custody Nominee (UK) Ltd A/C 770286        531,950

 HSBC Global Custody Nominee (UK) Ltd A/C 357206   13,343,768

 HSBC Global Custody Nominee (UK) Ltd A/C 866203        685,888

 HSBC Global Custody Nominee (UK) Ltd A/C 361602        103,000

 HSBC Global Custody Nominee (UK) Ltd A/C 360509        666,163

 HSBC Global Custody Nominee (UK) Ltd A/C 766793        144,000

 HSBC Global Custody Nominee (UK) Ltd A/C 824434          65,000

 HSBC Global Custody Nominee (UK) Ltd A/C 924422        163,000




5. Number of shares / amount of stock acquired


 Not stated



6. Percentage of issued class


Not stated



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


12 May 2004



12. Total holding following this notification


18,912,492



13. Total percentage holding of issued class following this notification


5.00%



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


13 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