Holding(s) in Company

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:

Rockhopper Exploration 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:

Ignis Investment Services Limited

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

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

22 June 2010

6. Date on which issuer notified:

23 June 2010

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

5%

8. Notified details: Nominee holdings

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

ORD

GB00B0FVQX23

7,382,537

3.83%

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

CFD

2,244,735

1.17%

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

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

9,627,272

5.00%

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

Pearl Group Limited

Impala Holdings Limited

Pearl Group Holdings (No.1) Ltd

Ignis Asset Management Ltd

Ignis Investment Services Ltd (indirect)

Vidacos Nominees Ltd (5,760,445.00 2.99%)

Merrill Lynch (1,152,420.00 0.60%)

HSBC (1,092,315.00 0.57%)

State Street Nominees (1,021,284.00 0.53%)

BNY (OCS) Nominees Ltd (346,898.00 0.18%)

MELLON BANK NA (253,911.00 0.13%)

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:

Percentage calculation based on Issued Share Capital of 192,527,755

14. Contact name:

Deborah A. Wagner

15. Contact telephone number:

0141 222 8000