Holding in Company

Tullow Oil PLC
16 May 2006


Tullow Oil plc ('Tullow' or 'the Company')



Holding in Company



On 15 May 2006, Tullow received notification that Merrill Lynch & Co., Inc had a notifiable interest at 8 May 2006 in
90,396,898 ordinary shares of 10p each in the Company which represents 13.91% of the issued share capital of Tullow.



This total holding is held by a number of holding companies of Merrill Lynch Investment Managers Group Limited and by
certain other companies. Of the 90,396,898 ordinary shares in which Merrill Lynch & Co., Inc has a notifiable interest,
Merrill Lynch Investment Managers Group Limited has a notifiable interest of 90,182,598 shares (13.88%).



Tullow has been informed that as at 8 May 2006 the shares held by Merrill Lynch Investment Managers Group Limited to
which this notification relates were registered as follows:



Registered Holder                                 Number                        Beneficial

(if known)                                             Of Shares                     Interests



Nutraco Nominees Ltd                        48,331,619                   No

(Designated and Undesignated)



Britel (MAM) Nominees Ltd               1,095,700                    No



Merrill Lynch Pension                                83,111                    Yes

Nominees Ltd



Merrill Lynch Pension                           4,943,478                   Yes

Nominees Ltd A/C Noncert



Treasury of the                                      1,115,497                   No

Government of the Isle of Man

Nominees A/C 5



Treasury of the                                       1,863,346                  No

Government of the Isle of Man

Nominees A/C 10



Stamford Nominees                                  180,300                   No

Limited A/C CHARTY



Other names                                         32,569,547                  No



Total                                                    90,182,598





















                    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