Holding(s) in Company

For filings with the FSA include the annex

For filings with issuer exclude the annex

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

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

Serica 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 the notification obligation: iii

AXA S.A, 25 Avenue Matignon, 75008 Paris and its group of companies

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

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

23/09/2010

6. Date on which issuer notified:

24/09/2010

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

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

B0CY5V5

8,832,018

8,832,018

0

0

8,529,277

0.00

4.83

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

8,529,277

4.83%

9. Chain

Name of Company / Fund

Number of Shares

% of issued share capital

AXA IM UK

8,529,277.00

4.831950

Indirect

Total Direct

0

0.00000

Total Indirect

8,529,277

4.83195

TOTAL

8,529,277

4.83195

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:

Charles Tissier

15. Contact telephone number:

020 7003 1510