FORM 6-K

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                            Report of Foreign Issuer
                    pursuant to Rule 13a - 16 or 15d - 16 of
                       the Securities Exchange Act of 1934


                         For the period 19 December, 2005


                                Cookson Group plc

                          265 Strand, London, WC2R 1BD


     [Indicate by check mark whether the registrant files or will file annual 
      reports under cover Form 20-F or Form 40-F]

               Form 20-F    X                     Form 40-F 

[Indicate by check mark whether the  registrant  by furnishing  the  information
contained  in this  Form is  also  thereby  furnishing  the  information  to the
Commission  pursuant to Rule  12g3-2(b)  under the  Securities  Exchange  Act of
1934.]
                    Yes                                  No      X

[If "Yes" is marked,  indicate below the file number  assigned to the registrant
in connection with Rule 12g3-2(b): 82-]



Exhibit Index


Exhibit No.1 - Holding(s) in Company dated 19 December 2005
Exhibit No.2 - Holding(s) in Company dated 19 December 2005
Exhibit No.3 - SEC Deregistration/EGM Notice dated 19 December 2005




Exhibit No.1

                                  SCHEDULE 10

                    NOTIFICATION OF MAJOR INTERESTS IN SHARES

1) Name of company

COOKSON GROUP PLC

2) Name of shareholder having a major interest

BRITEL FUND TRUSTEES LIMITED

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

BRITEL FUND NOMINEES LTD (335,093 SHARES)
CHASE NOMINEES LTD (8,289,341 SHARES)

5) Number of shares/amount of stock acquired

N/A

6) Percentage of issued class

N/A

7) Number of shares/amount of stock disposed

NOT DISCLOSED

8) Percentage of issued class

NOT DISCLOSED

9) Class of security

ORDINARY SHARES OF 10 PENCE EACH

10) Date of transaction

15 DECEMBER 2005

11) Date company informed

16 DECEMBER 2005

12) Total holding following this notification

8,624,434 SHARES

13) Total percentage holding of issued class following this notification

4.53%

14) Any additional information

15) Name of contact and telephone number for queries

RACHEL BENJAMIN, COMPANY SECRETARIAL ASSISTANT, COOKSON GROUP PLC 
- 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: 19 DECEMBER 2005





Exhibit No.2

                                   SCHEDULE 10

                    NOTIFICATION OF MAJOR INTERESTS IN SHARES

1) Name of company

COOKSON GROUP PLC

2) Name of shareholder having a major interest

Hermes Focus Asset Management Limited and Hermes SLP Limited

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

CHASE NOMINEES LTD (5,357,118 SHARES)

5) Number of shares/amount of stock acquired

N/A

6) Percentage of issued class

N/A

7) Number of shares/amount of stock disposed

NOT DISCLOSED

8) Percentage of issued class

NOT DISCLOSED

9) Class of security

ORDINARY SHARES OF 10 PENCE EACH

10) Date of transaction

15 DECEMBER 2005

11) Date company informed

16 DECEMBER 2005

12) Total holding following this notification

5,357,118 SHARES (HERMES FOCUS ASSET  MANAGEMENT  LIMITED AND HERMES SLP LIMITED
ONLY)

13) Total percentage holding of issued class following this notification

2.82% (HERMES FOCUS ASSET MANAGEMENT LIMITED AND HERMES SLP LIMITED ONLY)

14) Any additional information

Hermes  SLP  Limited is only one of the  partners  of the  various  partnerships
managed by Hermes Focus Asset Management Limited.  Hermes Focus Asset Management
Limited is in turn a subsidiary of BriTel Fund Trustees Limited.

15) Name of contact and telephone number for queries

RACHEL BENJAMIN, COMPANY SECRETARIAL ASSISTANT, COOKSON GROUP PLC 
- 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: 19 DECEMBER 2005





Exhibit No.3

19 December 2005

                    Cookson announces intention to terminate
             SEC Registration and effect Capital Reduction - Update

On 17 October 2005, Cookson Group plc ("Cookson" or the "Company") announced its
intention  to seek  shareholder  approval at an  Extraordinary  General  Meeting
("EGM") to:

-    amend its Articles of  Association to allow the Directors to require its US
     resident   shareholders   to  sell  their  shares  in  order  to  terminate
     registration  of  its  ordinary  shares  ("De-registration")  with  the  US
     Securities and Exchange Commission ("SEC"); and

-    to effect a reduction of its share capital by:

     -    cancelling all of the deferred shares of 49 pence each, as the Company
          had undertaken to do at the time of its rights issue in 2002 (at which
          time such shares were  created),  in order to create a more  efficient
          capital structure; and

     -    cancelling  the  share  premium  account  of  the  Company  to  create
          additional reserves for the Group going forwards.

The necessary  preparatory  steps have now been  undertaken and Cookson is today
posting a circular to its shareholders explaining the proposed amendments to its
Articles of Association  and the other matters  outlined above and convening the
EGM  (the  "Circular").  The  EGM  will be held  on 12  January  2006.  Assuming
shareholders  approve  the  proposed  amendments  to the  Company's  Articles of
Association,  the Board intends to start the  procedures  required to effect any
necessary transfer of shares held by US residents immediately thereafter.  It is
the Board's  expectation  that the SEC  conditions  required to be  satisfied in
order to apply for  De-registration  will have been met during the first quarter
of 2006.

In  connection  with  the  above,  copies  of the  Circular  and a Form of Proxy
relating to the EGM will shortly be available  for  inspection at the UK Listing
Authority's Document Viewing Facility, which is situated at:

The Financial Services Authority
25 The North Colonnade
Canary Wharf
London
E14 5HS
Tel. no. + 44 (0) 20 7066 8224

Enquiries:
Richard Malthouse, Group Secretary Tel: + 44 (0) 20 7061 6500

About Cookson Group plc

Cookson  Group  plc  is a  leading  materials  science  company  which  provides
materials, processes and services to customers worldwide. The Group's operations
are formed into three divisions - Ceramics, Electronics and Precious Metals. The
Ceramics division is the world leader in the supply of advanced flow control and
refractory  products  and systems to the iron and steel  industry  and is also a
leading  supplier of refractory  lining  materials for iron and  steelmaking and
other industrial  processes.  The Electronics division is a leading manufacturer
and supplier of materials and services to the  electronics  industry,  primarily
serving  fabricators  and assemblers of printed  circuit  boards,  assemblers of
semiconductor  packaging and the electrical and industrial markets. The Precious
Metals  division is a leading  supplier to the jewellery  industry of fabricated
precious metals products.

Headquartered  in London,  Cookson  employs  some 16,000  people in more than 35
countries and sells its products in over 100 countries.

Cookson Group plc
265 Strand
London WC2R 1DB

Tel: +44 (0) 20 7061 6500
Fax: + 44 (0) 20 7061 6600
www.cooksongroup.co.uk





                                                   SIGNATURE
                                                   Cookson Group plc



                                                   By:________________
                                                   Rachel Fell 
                                                   Assistant Company Secretary


                                                   Date: 19 December 2005