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:

Avocet Mining 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:

J P Morgan Asset Management Holdings Inc 

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

J P Morgan Asset Management (UK) Limited

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

24th December 2009

6. Date on which issuer notified:

29th December 2009

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

5% Downwards

8. Notified details:

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

 GB0000663038

 12,150,000

 12,150,000

 9,632,062

 9,632,062

 4.96%

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

 N/A

 N/A

 N/A

 N/A

 N/A

Total (A+B)

Number of voting rights

Percentage of voting rights

 9,632,062

 4.96%

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

Total disclosable holding for JP Morgan Asset Management Holdings Inc: 9,632,062 (4.96%)

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:

14. Contact name:

 Miss Jay Supaya

15. Contact telephone number:

 +44 20 7325 4513