Petrel Resources Regulatory News (PET)

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: ii

Petrel Resources Plc

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

An acquisition or disposal of voting rights

YES

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

No

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

No

An event changing the breakdown of voting rights

No

Other (please specify):

No

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

Gartmore Investment Limited

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

Gartmore Fund Managers Limited / Gartmore Investment Limited

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

29th April 2010

6. Date on which issuer notified:

30th April 2010

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

5%

8. Notified details:

A: Voting rights attached to shares viii, ix

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 x

Direct

Direct xi

Indirect xii

Direct

Indirect

IE0001340177

3,443,173

3,443,173

3,964,000

3,964,000

5.171%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date xiii

Exercise/ Conversion Period xiv

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 xv, xvi

Resulting situation after the triggering transaction

Type of financial instrument

Exercise price

Expiration date xvii

Exercise/ Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

3,964,000

5.171%

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

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:

All figures are based on the Company's issued share capital of 76,664,624 as provided by Exshare

E mail contact RDU@Gartmore.com

14. Contact name:

RDU

15. Contact telephone number:

0207 782 2324

Note: Annex should only be submitted to the FSA not the issuer

Annex: Notification of major interests in share

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

Contact address

(registered office for legal entities)

Phone number & email

Other useful information

(at least legal representative for legal persons)

B: Identity of the notifier, if applicable

Full name

Gartmore Investment Limited

Contact address

Gartmore House, 8 Fenchurch Place, London EC3M 4PB

Phone number & email

020 7782 2324

RDU@Gartmore.com

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

Asset Manager

C: Additional information

For notes on how to complete form TR-1 please see the FSA website.