Holding(s) in Company

Tullow Oil PLC
13 September 2005

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

                               Holding in Company

On 12 September 2005, Tullow received notification that Merrill Lynch & Co., Inc
has a notifiable interest in 91,490,341 ordinary shares of 10p each in the
Company which represents 14.14 % of the issued share capital of Tullow.

This total holding is held by a number of holding companies of Merrill Lynch
Investment Managers Limited and by certain other companies. Of the 91,490,341
ordinary shares in which Merrill Lynch & Co., Inc has a notifiable interest,
Merrill Lynch Investment Managers Limited has a notifiable interest of
91,484,541 (14.14%). By virtue of a separate holding of 3,700 ordinary shares
Merrill Lynch Group, Inc has a notifiable interest of 91,488,241 ordinary shares
(14.14%%)

Tullow has been informed that the shares held by Merrill Lynch Investment
Managers Limited to which this notification relates are registered as follows:

Registered Holder                                                                       Number        Beneficial
                                                                                     Of Shares          Interest

Nutraco Nominees Limited (Designated and Undesignated)                              44,532,999                No
Merrill Lynch Pension Nominees Ltd A/C Noncert                                       5,229,624               Yes
Treasury of the Government of the Isle of Man Nominees A/C 5                         1,190,397                No
Treasury of the Government of the Isle of Man Nominees A/C 10                        1,166,046                No
Stamford Nominees Limited A/C CHARTY                                                   223,900                No
Other names                                                                         39,141,575                No
Total                                                                               91,484,541


13 September, 2005


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