Holding(s) in Company

For filings with the FCA include the annex

For filings with issuer exclude the annex

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

X

An event changing the breakdown of voting rights

Other (please specify):

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

JPMorgan Chase & Co.

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

J.P. Morgan Securities Plc

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

22 November 2016

6. Date on which issuer notified:

23 November 2016

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

5%, 4%, 3% Downwards

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

Direct

Direct

Indirect

Direct

Indirect

GB0001500809

6,510,764

6,510,764

Below minimum threshold

Below minimum threshold

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

Total (A+B+C)

Number of voting rights

Percentage of voting rights

Below minimum threshold

Below minimum threshold

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

Total disclosable holding for JPMorgan Chase & Co.: Below minimum threshold

Direct: J.P. Morgan Securities Plc: Below minimum threshold

Chain of control:

JPMorgan Chase & Co.

JPMorgan Chase Bank, National Association (100%)

J.P. Morgan International Inc. (100%)

Bank One International Holdings Corporation (100%)

J.P. Morgan International Finance Limited (100%)

J.P. Morgan Capital Holdings Limited (100%)

J.P. Morgan Chase (UK) Holdings Limited (99.99%)

J.P. Morgan Chase International Holdings (100%)

J.P. Morgan Securities plc (99.41%)

Proxy Voting:

10. Name of the proxy holder:

N/A

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

N/A

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

N/A

13. Additional information:

N/A

14. Contact name:

Kevin Massie

Corporate Counsel & Company Secretary

Tullow Oil plc

15. Contact telephone number:

020 3249 9000