Notification of Major Interes

RNS Number : 2979J

Tullow Oil PLC

26 March 2010

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):

24 March 2010

6. Date on which issuer notified:

26 March 2010

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

Holding has gone below 12%

8. Notified details:

A: Voting rights attached to shares ^{viii, ix}

Class/type of shares if possible using the ISIN CODE

Situation previous to the Triggering transaction

Ord 10p
GB0001500809

Number of shares

101,877,635*

Number of Voting Rights

101,877,635*

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	104,200,377	N/A	11.78%*

*Situation previous disclosure is based upon 803,795,253 shares in issue while the

resulting situation disclosure is based upon 884,749,772 shares in issue

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

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction
Type of financial instrument	Exercise Price	Exercise date ^xvii	Exercise / Conversion Period ^xviii	Number of voting rights instruments refers to	% of voting rights ^{xix, xx}
CFD				1,148,080	Nominal	Delta
					0.13%	0.13%