Bowleven Regulatory News (BLVN)

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

Bowleven Plc

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

An acquisition or disposal of voting rights

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):

Amendment - Please see box 13

YES

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

JPMorgan Asset Management Holdings Inc.

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

JPMorgan Asset Management (UK) Limited

JPMorgan Asset Management (Taiwan) Limited

JPMorgan Investment Management Inc.

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

N/A

6. Date on which issuer notified:

20 October 2010

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

12%

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

GB00B04PYL99

N/A

N/A

23,228,023

12.01%

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

23,228,023

12.01%

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

Total disclosable holding for JPMorgan Asset Management Holdings Inc : 23,228,023 (12.01%)

JPMorgan Asset Management (UK) Limited: 22,321,525 (11.54%)

JPMorgan Investment Management Inc.

JPMorgan Asset Management (Taiwan) Limited

Proxy Voting:

10. Name of the proxy holder:

N/A

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

N/A

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

N/A

13. Additional information:

This is an amendment to the notification which was made on 19th October 2010

14. Contact name:

Kartik Parekh

15. Contact telephone number:

020 7325 9387