Vesuvius Regulatory News (VSVS)

TR-1: NOTIFICATION OF MAJOR INTERESTS IN SHARES

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

COOKSON GROUP PLC

2. Reason for the notification (please state Yes/No):

An acquisition or disposal of voting rights: (Yes)

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

An event changing the breakdown of voting rights: ( )

Other (please specify) ( )

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

Ignis Investment Services Limited

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

5. Date of the transaction (and date on which the threshold is crossed or reached if different): 27 September 2012

6. Date on which issuer notified: 28 September 2012

7. Threshold(s) that is/are crossed or reached: 3%

8. Notified details:

A: Voting rights attached to shares

Resulting situation after the triggering transaction

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Total (A+B+C)

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

Vidacos Nominees Ltd (7,471,108.00 2.69%)

BNY (OCS)Nominees Ltd (783,194.00 0.28%)

Phoenix Group Holdings

Impala Holdings Limited

Ignis Asset Management Ltd

Ignis Investment Services Ltd (indirect)

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:

RACHEL FELL, DEPUTY SECRETARY, COOKSON GROUP PLC

15. Contact telephone number:

+ 44 (0)20 7822 0000