TR-1: NOTIFICATION OF MAJOR INTEREST 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 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 the
notification obligation:

The Capital Group Companies, Inc.

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

See Section 9

5. Date of the transaction and date on
which the threshold is crossed or
reached:

5 January 2015

6. Date on which issuer notified:

6 January 2015

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

Above 11%

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

Resulting situation after the triggering transaction

Number
of
Shares

Number
of
Voting
Rights

Number
of shares

Number of voting
rights

% of  voting rights

Direct

Direct

Indirect

Direct

Indirect

Ordinary Shares (GB0001500809)

97,267,150

97,267,150

100,237,951

11.008%

Unsponsored ADRs

(US8994152028)

264,898

132,449

131,699

0.014%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial
instrument

Expiration
date

Exercise/
Conversion Period

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

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

100,369,650

11.022%

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

As of 5 January 2015

Number of SharesPercent of Outstanding

The Capital Group Companies, Inc. ("CG") holdings100,369,650                       11.022%

Holdings by CG Management Companies and Funds:

• Capital Guardian Trust Company                                                             8,731,592                         0.959%

• Capital International Limited                                                                        416,300                         0.046%

• Capital International SÁrl                                                                          1,971,346                         0.216%

• Capital International, Inc.                                                                          2,694,818                         0.296%

• Capital Research and Management Company                                      86,555,594                         9.505%

• AMCAP FUND

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:

Kevin Massie

15. Contact telephone number:

+44(0) 203 249 9000