Re: Holding in Company

Tullow Oil PLC
16 December 2005

Tullow Oil Plc



Re: Holding in Company



A letter from Tullow Oil Plc to the Irish Stock Exchange, received by the Irish
Stock Exchange on the 15 December 2005.







Tullow Oil plc ('the Company')

Holding in Company



The Company was informed on 14 December 2005 by M & G Investment Management
Limited (for and on behalf of Prudential plc) that as at 12 December 2005,
Prudential plc and certain of its subsidiary companies have in aggregate a
notifiable interest in 65,127,864 ordinary shares of 10 pence each representing
10.06 % 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 14 December 2005 sent to Tullow Oil plc












The Company Secretary

Tullow Oil plc

3rd Floor, Building 11

Chiswick Park

566 Chiswick High Road

London

W4 5YS



Fax: [phone]
     14 December 2005





Dear Sir/Madam,



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.



Yours faithfully







Richard Harding

for and on behalf of Prudential plc



Direct Line:       020 7548 3183

Direct Fax:       [phone]



Enc.







             Notifiable Position Report for Tullow Oil ORD GBP0.10

                             As at 12 December 2005



Percentage holdings are calculated using an issued share capital of  647,211,073
ORD GBP0.10 shares



            Registered Holder        Holdings                      %
Prudential plc                                      65,127,864            10.06        Total Notifiable
                                                                                       Interest
                          MAGIM HSBC NOM (UK)         39,439
                          SALI
                          NORTRUST NOMINEE LTD       128,612
                          A/C MHF01
                          NORTRUST NOMINEE LTD       952,710
                          A/C MHI01
                          NORTRUST NOMINEE LTD      1,515,511
                          A/C MHJ01
                          NORTRUST NOMINEE LTD      2,255,785
                          A/C MKB01
                          NORTRUST NOMINEE LTD      32,000,000
                          A/C MKK01
                          NORTRUST NOMS               22,664
                          NORTRUST NOMS LTD A/C     8,000,000
                          MEB01
                          NORTRUST NOMINEE LTD      11,482,863
                          A/C MEJ01
                          NORTRUST NOMINEE LTD        61,208
                          A/C PUF01
                          NORTRUST NOMINEE LTD       702,245
                          A/C PUR01
                          PRUCLT HSBC GIS NOM       5,038,396
                          (UK)PAC AC
                          PRUCLT HSBC GIS NOM       2,760,084
                          (UK)PPL AC
                          PRUCLT HSBC NOM(UK)         19,129
                          EQBF AC
                          PRUCLT HSBC NOM(UK)         31,708
                          MNBF AC
                          PRUCLT HSBC NOM(UK)        117,510
                          PENE AC






This announcement has been issued through the Companies Announcement Service of

                           the Irish Stock Exchange.






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