Holding(s) in Company

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

Nostrum Oil & Gas plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

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):

Disposal pursuant to settlement arrangements as referred to in announcement by the issuer dated 13 June 2017

YES

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

Frank MONSTREY and Petra NOE

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

CLAREMONT HOLDINGS C.V.

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

9 June 2017

6. Date on which issuer notified:

14 June 2017

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

reduced below 13%, 12%, 11%, 10%, 11% and 10%

8. Notified details:

A: Voting rights attached to shares viii, ix

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 xi

Indirect xii

Direct

Indirect

24,888,950

24,888,950

17,798,950

17,798,950

NIL

9.46%

NIL

GB00BGP6Q951

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

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

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

%

Total (A+B+C)

Number of voting rights

Percentage of voting rights

17,798,950

9.46%

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

Frank Monstrey and his spouse Petra Noé

STAK Adunatio (wholly owned by Frank Monstrey and his spouse Petra Noé)

B.M. Lumina (wholly owned by STAK Adunatio)

Septemium Investments SA (wholly owned by B.M. Lumina)

Eternum Holdings Sarl (wholly owned by Septemium Investments S.A.)

Claremont Holdings C.V. (wholly owned by Eternum Holdings Sàrl)

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:

Karolien Christiaens

15. Contact telephone number:

+31 20 737 03 32