Holding in Company

RNS Number : 0427A

Tullow Oil PLC

28 July 2008

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):

25 July 2008

6. Date on which issuer notified:

28 July 2008

7. Threshold(s) that is/are crossed or reached:

Gone above 13%

8. Notified details:

A: Voting rights attached to shares

Class/type of shares if possible using the ISIN CODE

Situation previous to the Triggering transaction

Ord 10p
GB0001500809

Number of shares

93,506,155

93,506,155

Resulting situation after the triggering transaction
Class/type of shares if possible using the ISIN CODE	Number of shares	Number of voting rights		% of voting rights
	Direct	Direct	Indirect	Direct	Indirect
Ord 10p GB0001500809	N/A	N/A	94,727,571	N/A	13.07%

B: Financial Instruments

Resulting situation after the triggering transaction (xii)

Type of financial instrument	Expiration Date (xiii)	Exercise/Conversion Period/ Date (xiv)	Number of voting rights that may be acquired if the instrument is exercised/ converted.	% of voting rights