Holding(s) in Company

Cookson Group PLC
27 June 2006

                                  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

MORLEY FUND MANAGEMENT LTD:

BNY NORWICH UNION NOMINEES LTD      2,273,322
CHASE GA GROUP NOMINEES LTD         5,094,700
CHASE NOMINEES LTD                    212,480
CUIM NOMINEE LTD                    2,047,237

5) Number of shares/amount of stock acquired

507,034

6) Percentage of issued class

0.26%

7) Number of shares/amount of stock disposed

N/A

8) Percentage of issued class

N/A

9) Class of security

ORDINARY SHARES OF 10 PENCE EACH

10) Date of transaction

26 JUNE 2006

11) Date company informed

27 JUNE 2006

12) Total holding following this notification

9,627,739 SHARES

13) Total percentage holding of issued class following this notification

5.00%

14) Any additional information

N/A

15) Name of contact and telephone number for queries

RACHEL FELL, DEPUTY SECRETARY, COOKSON GROUP PLC - TEL: [phone]


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

RACHEL FELL, DEPUTY SECRETARY, COOKSON GROUP PLC

Date of notification: 27 JUNE 2006






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