Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached:

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 qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation:

Commonwealth Bank of Australia on behalf of the controlled undertaking;

First State Investments (UK) Limited

First State Investments (Singapore)

First State Investments International Limited

Realindex Investments Pty Limited

4. Full name of shareholder(s)  (if different from 3.):

5. Date of the transaction and date onwhich the threshold is crossed orreached:

3rd December 2015

6. Date on which issuer notified:

7th December 2015

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

>3%

8. Notified details:

A: Voting rights attached to shares

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct

Indirect

Direct

Indirect

25,062,619

25,062,619

28,054,427

28,054,427

3.08%

GB0001500809

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate

Exercise/Conversion Period

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

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

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date

Exercise/Conversion period

Number of voting rights instrument refers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

28,054,427

3.08%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable:

First State Investments (UK) Limited - 16,626,532 - 1.82%

First State Investments (Singapore) - 11,030,339 - 1.21%

First State Investments International Limited - 332,810 - 0.04%

Realindex Investments Pty Limited - 64,746 - 0.01%

Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will ceaseto hold:

12. Date on which proxy holder will cease to holdvoting rights:

13. Additional information:

Please be advised 911,570,410 was used as the denominator

14. Contact name:

Kevin Massie

Corporate Counsel & Deputy Company Secretary

Tullow Oil Plc

15. Contact telephone number:

020 3249 9000