Holding(s) in Company

Tullow Oil PLC 15 June 2007 TR-1(i): NOTIFICATION OF MAJOR INTERESTS IN SHARES 1. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached : TULLOW OIL PLC 2. Reason for the notification (please tick the appropriate box or boxes) An acquisition or disposal of voting rights: ( X ) An acquisition or disposal of financial instruments which may result in the acquisition of shares already issued to which voting rights are attached: ( ) An event changing the breakdown of voting rights: ( ) Other (please specify): ( ) 3. Full name of person(s) subject to the notification obligation : BLACKROCK, INC 4. Full name of shareholder(s) (if different from 3.) : 5. Date of the transaction (and date on which the threshold is crossed or reached if different) : 12 JUNE 2007 6. Date on which issuer notified: 14 JUNE 2007 7. Threshold(s) that is/are crossed or reached: GONE ABOVE 16% 8. Notified details: A: Voting rights attached to shares Class/type of shares if possible Situation previous to the Triggering transaction using the ISIN CODE Number of shares Number of voting Rights Ord 10p GB0001500809 107,746,819 107,746,819 Resulting situation after the triggering transaction Class/type of shares if Number of shares Number of voting rights % of voting rights possible using the ISIN CODE Direct Direct Indirect Direct Indirect Ord 10p N/A N/A 117,237,930 N/A 16.31% GB0001500809 B: Financial Instruments Resulting situation after the triggering transaction (xii) Type of Expiration Date Exercise/Conversion Number of voting rights % of voting rights financial (xiii) Period/ Date (xiv) that may be acquired if the instrument instrument is exercised/ converted. Total (A+B) Number of voting rights % of voting rights 117,237,930 16.31% 9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable (xv): BLACKROCK INVESTMENT MANAGEMENT (UK) LIMITED -117,237,930 (16.31%) Proxy Voting: 10. Name of the proxy holder: 11. Number of voting rights proxy holder will cease to hold: 12. Date on which proxy holder will cease to hold voting rights: 13. Additional information: 14. Contact name: TOM HICKEY, COMPANY SECRETARY 15. Contact telephone number: 0208 996 1000 This information is provided by RNS The company news service from the London Stock Exchange

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Tullow Oil (TLW)
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