Re: Holding in Company

Tullow Oil PLC
10 June 2004

Tullow Oil plc





10 June 2004





Re: Holding in Company



A letter from Tullow Oil Plc dated 09 June 2004 to the Irish Stock Exchange,
received by the Irish Stock Exchange on the 09 June 2004.



Tullow Oil plc ('the Company')

Holding in Company



The Company was informed on 8 June 2004 by M & G Investment Management Limited
(for and on behalf of Prudential plc) that as at 7 June 2004, Prudential plc and
certain of its subsidiary companies have in aggregate a notifiable interest in
63,248,779 ordinary shares of 10 pence each representing 10.12 % 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 08 June 2004 to Tullow Oil Plc.





08 June 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 id Laurence Pountney Hill London EC4R 0HH



Richard Harding

For and on behalf of Investment Funds Plc















             Notifiable Position Report for Tullow Oil ORD GBP0.10

                               As at 07 June 2004



Percentage holdings are calculated using an issued share capital of  624,739,799
ORD GBP0.10 shares



           Registered Holder         Holdings                       %
Prudential plc                                      63,248,779            10.12        Total Notifiable
                                                                                       Interest
                          Chase Nominees Ltd        6,282,863
                          AUST
                          Chase Nominees Ltd        1,611,171
                          ILIF
                          Chase Noms Ltd             186,161
                          Clydesdale BK Noms        9,770,692
                          Ltd MGA
                          Clydesdale BK Noms        38,632,586
                          Ltd MGG
                          Clydesdale BK Noms        1,200,000
                          Ltd MGK
                          Clydesdale BK Noms          56,800
                          Ltd MGT
                          Pruclt HSBC GIS NOM       3,500,000
                          (UK) PAC AC
                          Pruclt HSBC GIS NOM       1,810,055
                          (UK) PPL AC
                          RBS Edinburgh Noms LD      198,451
                          A/C SAGP
M&G Group Limited                                   63,050,328            10.09
                          Chase Nominees Ltd        6,282,863
                          AUST
                          Chase Nominees Ltd        1,611,171
                          ILIF
                          Chase Noms Ltd             186,161
                          Clydesdale BK Noms        9,770,692
                          Ltd MGA
                          Clydesdale BK Noms        38,632,586
                          Ltd MGG
                          Clydesdale BK Noms        1,200,000
                          Ltd MGG
                          Clydesdale BK Noms          56,800
                          Ltd MGT
                          Pruclt HSBC GIS NOM       3,500,000
                          (UK) PAC AC
                          Pruclt HSBC GIS NOM       1,810,055
                          (UK) PPL AC
M&G Investment Management                           62,993,528            10.08
         Limited
                          Chase Nominees Ltd        6,282,863
                          AUST
                          Chase Nominees Ltd        1,611,171
                          ILIF
                          Chase Noms Ltd             186,161
                          Clydesdale BK Noms        9,770,692
                          Ltd MGA
                          Clydesdale BK Noms        38,632,586
                          Ltd MGG
                          Clydesdale BK Noms        1,200,000
                          Ltd MGG
                          Pruclt HSBC GIS NOM       3,500,000
                          (UK) PAC AC
                          Pruclt HSBC GIS NOM       1,810,055
                          (UK) PPL AC





             Notifiable Position Report for Tullow Oil ORD GBP0.10

                               As at 07 June 2004



Percentage holdings are calculated using an issued share capital of 624,739,799
ORD GBP0.10 shares





     Registered Holder         Holding                                    %


     M&G Limited                                           63,050,328                   10.09
                       Chase Nominees Ltd AUST              6,282,863
                       Chase Nominees Ltd ILIF              1,611,171
                       Chase Noms Ltd                        186,161
                       Clydesdale BK Noms Ltd MGA           9,770,692
                       Clydesdale BK Noms Ltd MGG          38,632,586
                       Clydesdale BK Noms Ltd MGK           1,200,000
                       Clydesdale BK Noms Ltd MGT            56,800
                       Pruclt HSBC GIS NOM (UK)             3,500,000
                       PAC AC
                       Pruclt HSBC GIS NOM (UK)             1,810,055
                       PPL AC







This announcement has been issued through the Companies Announcement Service of

                           the Irish Stock Exchange.












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