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

FIL Limited

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

See attached schedule

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

24 May 2010

6. Date on which issuer notified:

25 May 2010

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

10%

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

GB00B0CY5V57

17,675,012

17,675,012

17,607,512

17,607,512

9.97

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

17,607,512

9.97%

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

See attached schedule

Proxy Voting:

10. Name of the proxy holder:

FIL Limited

11. Number of voting rights proxy holder will cease to hold:

67,500

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

24 May 2010

13. Additional information:

None

14. Contact name:

Shaheen Hussain

15. Contact telephone number:

[email protected]

SHARES HELD

NOMINEE

MANAGEMENT

COMPANY

1,889,900

JP MORGAN, BOURNEMOUTH

FII

15,717,612

JP MORGAN, BOURNEMOUTH

FISL

FIL Limited (FIL) is the parent holding company for various direct and indirect subsidiaries, including FIL Fund Management Limited (FFML), FIL Investment Services Ltd (FISL), FIL Gestion (FIGEST), FIL Asset Management (Korea) Limited (FIAKL), FIL Investments Management (Hong Kong) Limited (FIMHK), FIL Pension Management (FPM), Fidelity Investments Japan (FIJ) and FIL Investments International (FII), investment managers for various non-US investment companies and institutional clients