Exhibit 2.3 Amendment No. 1 to the Deposit Agreement between Cookson, Citibank NA, as depositary, and the holders and
beneficial owners of American Depositary Receipts dated 3 June 2005



COOKSON GROUP PLC



AND



CITIBANK, N.A.,

As Depositary



AND



HOLDERS AND
BENEFICIAL OWNERS

FROM TIME TO TIME OF

AMERICAN DEPOSITARY RECEIPTS







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Amendment No. 1



to



Deposit Agreement



Dated as of 3 June, 2005



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AMENDMENT NO. 1 TO DEPOSIT AGREEMENT



AMENDMENT NO. 1 TO DEPOSIT AGREEMENT, is made as of 3 June, 2005 (the Amendment), by and among
COOKSON GROUP PLC a public company limited by shares existing under the laws of England and Wales (the Company), CITIBANK, N.A., a national banking association organized under the laws of the United States of America and acting solely as
depositary (the Depositary), and all Holders from time to time of American Depositary Receipts issued under the Deposit Agreement.



W I T N E S S E T H    T H A T



WHEREAS, the parties hereto entered into that
certain Deposit Agreement, dated as of September 14, 1998, (the Deposit Agreement), for the creation of American Depositary Receipts (ADRs) evidencing American Depositary Shares (ADSs) representing the Shares so
deposited and for the execution and delivery of such ADRs evidencing such ADSs;



WHEREAS, the Company has changed the par value of its Shares (set forth in Section 1.27 of the Deposit Agreement) from 1p to 10p, and desires to amend the Deposit Agreement to reflect such change;



WHEREAS,the Company has changed the ratio of Shares to ADSs (as
set forth in Section 1.2 of the Deposit Agreement) from (i) five (5) Shares to one (1) ADS to (ii) one (1) Share to two (2) ADSs, and desires to amend the Deposit Agreement to reflect such changes; and



WHEREAS, pursuant to Section 6.01 of the Deposit Agreement, the
Company and the Depositary deem it necessary and desirable to amend the Deposit Agreement and the form of ADR annexed thereto as Exhibit A for the purposes set forth herein;



NOW, THEREFORE,for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged,
the Company and the Depositary hereby agree to amend the Deposit Agreement as follows:



ARTICLE I



DEFINITIONS



SECTION 1.01.
Definitions. Unless otherwise defined in this Amendment, all capitalized terms used, but not otherwise defined, herein shall have the meaning given to such terms in the Deposit Agreement.



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ARTICLE II



AMENDMENTS TO DEPOSIT AGREEMENT



SECTION 2.01. Deposit Agreement. All references in the Deposit Agreement to the term Deposit Agreement shall, as of the
Effective Date (as herein defined), refer to the Deposit Agreement, dated as of September 14, 1998, as further amended by this Amendment.



SECTION 2.02. Change of Par Value. Section 1.27 of the Deposit Agreement is amended by deleting in its entirety and replacing it with the
following:



SECTION 1.27 Shares shall
mean the Companys ordinary shares, 10p each, validly issued and outstanding and fully paid and may, if the Depositary so agrees after consultation with the Company, include evidence of the right to receive Shares; provided that in no event
shall Shares include evidence of the right to receive Shares with respect to which the full purchase price has not been paid or Shares as to which preemptive rights have theretofore not been validly waived or exercised; provided further, however,
that, if there shall occur any change in par or nominal value, split-up, consolidation, reclassification, conversion or any other event described in Section 4.11, in respect of the Shares of the Company, the term Shares shall thereafter,
to the extent permitted by law, represent the successor securities resulting from such change in par or nominal value, split-up, consolidation, exchange, conversion, reclassification or event.



SECTION 2.03. Change of Ratio. All references made in the Deposit
Agreement to each American Depositary Share representing five (5) Shares shall, as of the Effective Date, refer to two (2) American Depositary Shares representing one (1) Share.



ARTICLE III



AMENDMENTS TO THE FORM OF ADR



SECTION 3.01. Change of Par Value. All references to par value of Shares of 1p each made in the ADRs issued and outstanding as of the Effective
Date shall refer to Shares of par value 10p each.



SECTION
3.02. Change of Ratio. All references made in the ADRs issued and outstanding to each American Depositary Share representing five (5) Shares shall, as of the Effective Date, refer to two (2) American Depositary Shares representing one (1) Share.



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ARTICLE IV



REPRESENTATIONS AND WARRANTIES



SECTION 4.01. Representations and Warranties. The Company represents and warrants to, and agrees with, the Depositary and the Holders, that
as of the date of this Amendment:



| | (a) | This Amendment, when executed and delivered by the Company to Citibank will be duly and validly authorized, executed and delivered by the Company, and constitute the legal, valid
and binding obligation of the Company, enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, moratorium and similar laws of general applicability relating to or affecting
creditors rights and to general equity principles;
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| | (b) | In order to ensure the legality, validity, enforceability or admissibility into evidence of this Amendment, and any other document furnished hereunder or thereunder in England and
Wales neither of such Amendment or document need to be filed or recorded with any court or other authority in England and Wales nor does any stamp or similar tax need to be paid in England and Wales on or in respect of such agreements;
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| | (c) | None of the terms of the Amendment violate or conflict with, nor does the execution and delivery of the Amendment, the filing of the Post-Effective Amendment or the consummation of
the transactions contemplated therein violate, or conflict with, the Certificate of Incorporation of the Issuer, the Bylaws of the Issuer, or any agreement to which the Issuer is a party or by which the Issuer is bound; and
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| | (d) | All of the information provided to the Depositary by the Company in connection with this Amendment is true, accurate and correct.
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ARTICLE V



MISCELLANEOUS



SECTION 5.01. Effective Date. This Amendment is dated as of the date set forth above and shall be effective as of such date (the
Effective Date).



SECTION 5.02. New
ADRs. From and after the Effective Date, the Depositary shall arrange to have new ADRs printed or amended that reflect the changes to the form of ADRs effected by this Amendment. All ADRs issued hereunder after the Effective Date, once such
new ADRs are available, whether upon the deposit of Shares or other Deposited Securities or upon the transfer, combination or split-up of existing ADRs, shall be substantially in the form of the specimen ADRs attached as Exhibit A hereto.
However, ADRs issued prior or subsequent to the date hereof, which do not reflect the changes to the form of ADRs effected hereby, do not need to be called in for exchange and may remain outstanding until such time as the Holders



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thereof choose to surrender them for any reason under the Deposit Agreement. The Depositary is authorized and directed to take any and all lawful actions
deemed necessary to effect the foregoing.



SECTION 5.03.
Notice of Amendment to Holders. The Depositary is hereby directed to send notices informing the Holders of (i) the terms of this Amendment, (ii) the Effective Date of this Amendment and (iii) that the Holders shall be given the
opportunity, but that it is unnecessary, to surrender outstanding ADRs.



SECTION 5.04. Ratification.Except as expressly amended hereby, the terms, covenants and conditions of the Deposit Agreement as originally executed shall remain in full force and effect.



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IN WITNESS WHEREOF, the Company and the Depositary have caused this Amendment to be executed by
representatives thereunto duly authorized as of the date set forth above.



COOKSON GROUP PLCBy:

/s/    Nicholas R SalmonName:

NICHOLAS SALMONTitle:

CHIEF EXECUTIVEBy:

/s/    Dennis H MillardName:

Dennis MillardTitle:

CHIEF FINANCIAL OFFICERCITIBANK, N.A., as DepositaryBy:

/s/    Mary GormleyName:

MARY GORMLEYTitle:

VICE PRESIDENT




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