Holding(s) in Company

Cookson Group PLC
04 October 2005

                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES

1) Name of company

COOKSON GROUP PLC

2) Name of shareholder having a major interest

AVIVA PLC AND ITS SUBSIDIARIES

3) Please state whether notification indicates that it is in respect of
holding of the shareholder named in 2 above or in respect of a
non-beneficial interest or in the case of an individual holder if it is a
holding of that person's spouse or children under the age of 18

AS ABOVE

4) Name of the registered holder(s) and, if more than one holder, the
number of shares held by each of them

BNY NORWICH UNION NOMINEES LTD - 3,103,735 SHARES

CHASE GA GROUP NOMINEES LTD - 2,510,682 SHARES

CHASE NOMINEES LIMITED - 536,640 SHARES

CUIM NOMINEE LIMITED - 2,793,781 SHARES

5) Number of shares/amount of stock acquired

2,200

6) Percentage of issued class

0.001%

7) Number of shares/amount of stock disposed

701,390

8) Percentage of issued class

0.37%

9) Class of security

ORDINARY SHARES OF 10 PENCE EACH

10) Date of transaction

3 OCTOBER 2005

11) Date company informed

4 OCTOBER 2005

12) Total holding following this notification

8,944,838* SHARES

* BENEFICIAL INTEREST ONLY

13) Total percentage holding of issued class following this notification

4.71%

14) Any additional information



15) Name of contact and telephone number for queries

RACHEL BENJAMIN, COMPANY SECRETARIAL ASSISTANT, COOKSON GROUP PLC - TEL: 020
7061 6565

16) Name and signature of authorised company official responsible for
making this notification

RACHEL BENJAMIN, COMPANY SECRETARIAL ASSISTANT, COOKSON GROUP PLC

Date of notification: 4 OCTOBER 2005


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