.
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:
BlackRock, Inc

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):
18 December 2009

6. Date on which issuer notified:
22 December 2009

7. Threshold(s) that is/are crossed or reached:
Holding has gone above 11%
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 shares Number of voting
                                                     Rights

GB00B3WK5475                             28,567,619       28,567,619


Resulting situation after the triggering transaction

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

                                       Direct       Direct Indirect   Direct Indirect

GB00B3WK5475                            N/A         N/A    29,763,260  N/A   10.77


B: Qualifying Financial Instruments
Resulting situation after the triggering transaction

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




                                      N/A

C: Financial Instruments with similar economic effect to Qualifying Financial
Instruments
Resulting situation after the triggering transaction

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

                                                                                        Nominal Delta

     CFD        N/A       N/A          N/A                      695,518                  0.25

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

30,458,778             11.02


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

BlackRock Investment Management (UK) Limited - 30,458,778 (11.02%)

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:
020 7822 0000

END