Holding(s) in Company

Cookson Group PLC
11 April 2008



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:

STANDARD LIFE INVESTMENTS LTD



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

VIDACOS NOMINEES



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

10 APRIL 2008



6. Date on which issuer notified:

    11 APRIL 2008



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

13%



8. Notified details:


A: Voting rights attached to shares


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


GB00B07V4P80                      27,641,069                         27,641,069



Resulting situation after the triggering transaction


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


GB00B07V4P80                 27,540,759               14,892,348   12,648,411           7.005       5.950



B: Financial Instruments

Resulting situation after the triggering transaction


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

                                                      N/A



Total (A+B)
Number of voting rights        % of voting rights


27,540,759                     12.955



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

STANDARD LIFE INVESTMENTS LTD



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:

SILVANA GLIBOTA-VIGO, COMPANY SECRETARIAL ASSISTANT, COOKSON GROUP PLC


15. Contact telephone number:

+  44 (0)20 7822 0000




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