REG-Cookson Group PLC: Holding(s) in Company

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:

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

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):

17 JANUARY 2008

6. Date on which issuer notified:

21 JANUARY 2008

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

5%

8. Notified details:

……………..

A: Voting rights attached to shares

Class/type of shares if possible Situation previous to the
using the ISIN CODE Triggering transaction

Number of Number of voting
shares Rights

BO7V4P8 14,373,285 14,373,285

Resulting situation after the triggering transaction

Class/type of shares if possible Number of Number of voting % of voting
using the ISIN CODE shares rights rights

Direct Direct Indirect Direct Indirect

BO7V4P8 1,327,554 1,327,554 6,872,340 0.62 3.23

B: Financial Instruments

Resulting situation after the triggering transaction

Type of Expiration Exercise/ Number of voting rights that may be % of
financial Date Conversion acquired if the instrument is voting
instrument Period/ Date exercised/ converted. rights

N/A

Total (A+B)

Number of voting % of voting
rights rights

8,199,894 3.86

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

Name of Company / Fund Number of % of issues share Direct /
Shares capital Indirect

AXA Ireland Pension Fund 2,400 0.00113 Indirect

AXA Rosenberg 222,791 0.10481 Direct

AXA UK Investment Co ICVC Global 3,553 0.00167 Indirect
Distribution Fund

AXA UK Investment Co ICVC Global 28,000 0.01317 Indirect
Growth Fund

AXA UK Investment Co ICVC 20,000 0.00941 Indirect
Distribution Fund

AXA UK Investment Co ICVC UK 250,000 0.11761 Indirect
Opportunities Fund

AXA Rosenberg 170,588 0.08025 Direct

AXA Colonia Konzern 5,600 0.00263 Direct

AXA Colonia Konzern 15,192 0.00715 Indirect

AXA France 1,961 0.00092 Indirect

AXA Rosenberg 6,529,534 3.07181 Indirect

Sun Life Pensions Management Ltd 11,073 0.00521 Direct

Sun Life Pensions Management Ltd 4,500 0.00212 Direct

Sun Life Unit Assurance Ltd FTSE All 35,462 0.01668 Direct
Share Tracker

Sun Life Pensions Management FTSE 171,438 0.08065 Direct
All Share Tracker

Framlington onshore private clients 21,700 0.01021 Indirect

AXA Winterthur 489,785 0.23042 Direct

Axa Sun Life With Profits Passive 145,221 0.06832 Direct

Axa Sun Life With Profits Passive 71,096 0.03345 Direct

Total Direct 1,327,554 0.62455

Total Indirect 6,872,340 3.23309

TOTAL 8,199,894 3.85763

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

END