Notification of Major Interest in Shares

For filings with the FCA include the annex

For filings with issuer exclude the annex

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARES i

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

Ophir Energy 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: iii

RS Investment Management Co. LLC, an investment adviser registered with the U.S. Securities and Exchange Commission.

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

Registered Holders:

Aurora Nominees Ltd.

BNY Mellon Nominees Limited

Bank of New York, Brussels

JP Morgan Chase Nominees Limited

Northern Trust Nominees Ltd.

Pershing Nominees Ltd.

State Street Nominees Limited

The Bank of New York Mellon

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

12 June 2013

6. Date on which issuer notified:

13 June 2013

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

5% of total voting rights

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

Indirect xii

Direct

Indirect

GB00B24CT194

29,378,617

29,378,617

(4.99%)

29,421,289

N/A

29,421,289

N/A

5.00%

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

None

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

None

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

29,421,289

5.00%

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

Not applicable

Proxy Voting:

10. Name of the proxy holder:

Not applicable

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

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

13. Additional information:

RS Investment Management Co. LLC

388 Market Street, Suite 1700

San Francisco, CA 94111 USA

14. Contact name:

Marianne Clark

15. Contact telephone number:

(415) 591-2700