Holding in Company

Tullow Oil PLC
14 January 2004

Tullow Oil plc





14 January 2004





Re: Holding in Company



The Company was informed on 12 January 2004 by M & G Investment Management
Limited on behalf of Prudential plc that as at 8 January 2004 Prudential plc and
certain of its subsidiary companies  have a notifiable interest in 51,145,175
ordinary shares of 10 pence each ('Ordinary Shares') representing 13.53% of the
issued share capital of the Company.  The notification was triggered by the
reduction in the notifiable interest of M & G Securities Limited (a subsidiary
of Prudential plc) to 45,226,211 Ordinary Shares representing 11.96% of the
issued share capital of the Company.  The full text of the letter from M & G
Investment Management Limited Follows:





A letter from M & G Investments dated 09 January 2004 to Tullow Oil plc,
received by Tullow Oil plc on the 12 January 2004.



Companies Act 1985 (as amended)

Disclosure of Interests in Shares





In accordance with Part VI of the Companies Act 1985 (as amended)(the 'Act'), we
write to inform you that Prudential plc and certain of its subsidiary companies
have a notifiable interest in the issued share capital of your company as
detailed in the attached schedule.



For the purposes of S210 of the Act, the address for those companies identified
in the attached schedule is Laurence Pountney Hill London EC4R 0HH



Richard Harding

For and on behalf of Prudential plc













             Notifiable Position Report for Tullow Oil ORD GBP0.10

                             As at 08 January 2004



Percentage holdings are calculated using an issued share capital of  377,841,915
ORD GBP0.10 shares



           Registered Holder         Holdings                       %
Prudential plc                                      51,145,175            13.53        Total Notifiable
                                                                                       Interest
                          Chase Nominees Ltd        4,500,000
                          Aust



                          Chase Nominees Ltd
                          ILIF                      1,300,000



                          Chase Noms Ltd

                                                     109,518

                          Chase Noms Ltd A/C
                          14922
                                                     370,698


                          Clydesdale BK Noms
                          Ltd MGA

                                                    7,295,601

                          Clydesdale BK Noms
                          Ltd MGC


                                                     823,810
                          Clydesdale BK Noms
                          Ltd MGG



                          Clydesdale BK Noms        31,250,000
                          Ltd MGT



                          Nortrust Noms Ltd
                                                      56,800


                          Pruclt HSBC GIS Nom
                          (UK) PAC AC

                                                     406,625

                          Pruclt HSBC GIS Nom
                          (UK) PPL AC


                                                    3,500,000
                          RBS Edinburgh Noms
                          Ltd A/C SAGP





                                                    1,372,000







                                                     160,123
M&G Group Limited                                   50,985,052            13.49
                          Chase Nominees Ltd        4,500,000
                          Aust



                          Chase Nominees Ltd
                          ILIF                      1,300,000



                          Chase Noms Ltd

                                                     109,518

                          Chase Noms Ltd A/C
                          14922


                                                     370,698
                          Clydesdale BK Noms
                          Ltd MGA



                          Clydesdale BK Noms        7,295,601
                          Ltd MGC


                                                     823,810
                          Clydesdale BK Noms
                          Ltd MGG



                          Clydesdale BK Noms        31,250,000
                          Ltd MGT



                          Nortrust Noms Ltd
                                                      56,800


                          Pruclt HSBC GIS Nom
                          (UK) PAC AC

                                                     406,625

                          Pruclt HSBC GIS Nom
                          (UK) PPL AC


                                                    3,500,000







                                                    1,372,000
M&G Investment Management                           50,928,252            13.47
         Limited
                          Chase Nominees Ltd        4,500,000
                          Aust



                          Chase Nominees Ltd
                          ILIF                      1,300,000



                          Chase Noms Ltd

                                                     109,518

                          Chase Noms Ltd A/C
                          14922
                                                     370,698


                          Clydesdale BK Noms
                          Ltd MGA

                                                    7,295,601

                          Clydesdale BK Noms
                          Ltd MGC


                                                     823,810
                          Clydesdale BK Noms
                          Ltd MGG



                          Nortrust Noms Ltd         31,250,000



                          Pruclt HSBC GIS Nom
                          (UK) PAC AC
                                                     406,625


                          Pruclt HSBC GIS Nom
                          (UK) PPL AC

                                                    3,500,000







                                                    1,372,000



                                                    1,372,000





             Notifiable Position Report for Tullow Oil ORD GBP0.10

                             As at 08 January 2004



Percentage holdings are calculated using an issued share capital of 377,841,915
ORD GBP0.10 shares





     Registered Holder         Holding                                    %


     M&G Limited                                           50,985,052                   13.49
                       Chase Nominees Ltd Aust              4,500,000



                       Chase Nominees Ltd ILIF

                                                            1,300,000

                       Chase Noms Ltd



                       Chase Noms Ltd A/C 14922              109,518



                       Clydesdale BK Noms Ltd MGA            370,698



                       Clydesdale BK Noms Ltd MGC

                                                            7,295,601

                       Clydesdale BK Noms Ltd MGG



                       Clydesale BK Noms Ltd  MGT            823,810



                       Nortrust Noms Ltd

                                                           31,250,000

                       Pruclt HSBC GIS Nom (UK)
                       PAC AC


                                                             56,800
                       Pruclt HSBC GIS Nom (UK)
                       PPL AC



                                                             406,625





                                                            3,500,000



                                                            1,372,000
M&G Securities Limited                                     45,226,211                   11.96
                       Chase Nominees Ltd Aust              4,500,000



                       Chase Nominees Ltd ILIF

                                                            1,300,000

                       Clydesdale BK Noms Ltd MGA



                       Clydesdale BK Noms Ltd MGC           7,295,601



                       Clydesdale BK Noms Ltd MGG

                                                             823,810

                       Clydesdale BK Noms Ltd MGT



                                                           31,250,000





                                                             56,800











This announcement has been issued through the Companies Announcement Service of

                           the Irish Stock Exchange.






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