**Exhibit 2.4.2**

388 Greenwich Street 

14th Floor 

New York, NY 10013 

[Citi logo]

**October 12, 2007**

**Cemex S.A.B. de C.V. — Direct Registration System for ADSs**

Ladies and Gentlemen: 

Reference is made to Amendment No. 1 to the Second Amended and Restated Deposit Agreement, dated as of July 1,2005 (the “Deposit Agreement”), by and among Cemex S.A.B. de C.V. (the “Company”), Citibank, N.A., as Depositary (the “Depositary”), and all Holders and Beneficial Owners from time to time ofAmerican Depositary Receipts (“ADRs”) evidencing American Depositary Shares (“ADSs”) issued thereunder, each ADS representing ten (10) Shares (the “Shares”) of the Company. Capitalized termsused herein without definition shall have the meaning assigned thereto in the Deposit Agreement. 

The purposeof this letter agreement is to supplement the Deposit Agreement to enable the establishment by the Depositary of a “direct registration system” (the “DR System”) for ADSs and the issuance by the Depositary of“uncertificated ADSs” as part of the DR System. Therefore, the Company and the Depositary agree as follows: 

1. Notwithstanding any provision of the Deposit Agreement, the Depositary may, at any time and from time to time, issueADSs that are not evidenced by ADRs (such ADSs, the “Uncertificated ADSs”, and the ADSs evidenced by ADRs, the “Certificated ADSs”). 

2. Uncertificated ADSs shall not be represented by any instrument(s) but shall be evidenced only by the registration of“uncertificated securities” on the books and records of the Depositary maintained for such purpose. Any reference to Holders of ADR(s) or ADS(s) in the Deposit Agreement shall, in the context of the Uncertificated ADSs, refer to theperson(s) in whose name the Uncertificated ADSs are registered on the books of the Depositary maintained for such purpose. 

3. Holders of Uncertificated ADSs that are not subject to any registered pledges, liens, restrictions or adverse claims,of which the Depositary has written notice at such time, shall at all times have the right to exchange the Uncertificated ADSs (or any portion thereof) for Certificated ADSs of the same type and class, subject in each case to applicable laws and anyrules the Depositary may establish from time to time in respect of the Uncertificated ADSs. 

4. Holders ofCertificated ADSs shall, so long as the Depositary maintains the DR System for the ADSs, have the right to exchange the Certificated ADSs (or any portion thereof) for Uncertificated ADSs upon (i) the due surrender of the Certificated ADSs tothe Depositary for such purpose, and (ii) the presentation of a written request to such effect to the Depositary, 

subject in each case to (a) all liens and restrictions noted on the ADR evidencing the Certificated ADS(s) and all adverse claims of which the Depositary then has written notice,(b) the terms of the Deposit Agreement (as supplemented by this letter agreement) and the rules that the Depositary may establish from time to time for such purposes thereunder, and (c) applicable law. 

5. Uncertificated ADSs shall in all material respects be identical to Certificated ADSs of the same type and class,except that (i) no ADR(s) shall be, nor shall need to be, issued to evidence Uncertificated ADSs, (ii) Uncertificated ADSs shall, subject to the terms of the Deposit Agreement (as supplemented by this letter agreement), be transferableupon the same terms and conditions as uncertificated securities under New York law, (iii) each Holder’s ownership of Uncertificated ADSs shall be recorded on the books and records of the Depositary maintained for such purpose and evidenceof such Holder’s ownership shall be reflected in periodic statements provided by the Depositary to each such Holder in accordance with applicable law, (iv) the Depositary may from time to time, upon notice to the Holders of UncertificatedADSs affected thereby, establish rules and amend or supplement existing rules, as may be deemed reasonably necessary to maintain the DR System and for the issuance of Uncertificated ADSs on behalf of Holders, provided that such rules do not conflictwith the terms of the Deposit Agreement (as supplemented by this letter agreement) and applicable law, (v) the Holder of Uncertificated ADSs shall not be entitled to any benefits under the Deposit Agreement (as supplemented by this letteragreement) and such Holder’s Uncertificated ADSs shall not be valid or enforceable for any purpose against the Depositary or the Company unless such Holder is registered on the books and records of the Depositary maintained for such purpose,(vi) the Depositary may, in connection with any deposit of Shares resulting in the issuance of Uncertificated ADSs and with any transfer, pledge, release and cancellation of Uncertificated ADSs, require the prior receipt of such documentationas the Depositary may reasonably request, and (vii) upon termination of the Deposit Agreement (as supplemented by this letter agreement), the Depositary shall not require Holders of Uncertificated ADSs to affirmatively instruct the Depositaryor to take other action before remitting proceeds from the sale of the Deposited Securities represented by such Holders’ Uncertificated ADSs under the terms of Section 6.2 of the Deposit Agreement. 

6. When issuing ADSs under the terms of the Deposit Agreement, including, without limitation, issuances pursuant toSections 4.3, 4.4 and 4.5 thereof, the Depositary may in its discretion determine to issue Uncertificated ADSs rather than Certificated ADSs, unless otherwise specifically instructed in writing by the applicable Holder to issue Certificated ADSs.

7. Holders of Uncertificated ADSs may request the sale of ADSs through the Depositary, subject to the termsand conditions generally applicable to the sale of ADSs through the Depositary from time to time (which may be changed by the Depositary). 

8. All provisions and conditions of the Deposit Agreement shall apply to Uncertificated ADSs to the same extent as toCertificated ADSs, except as contemplated herein. The Depositary is authorized and directed to take any and all actions, and establish any and all procedures, deemed reasonably necessary to give effect to the terms hereof. Any references in theDeposit Agreement or any ADR(s) to the terms “American Depositary Share(s)” or “ADS(s)” shall, unless the context otherwise requires, include Certificated ADS(s) and Uncertificated ADS(s), individually or collectively, as thecontext may require. 

 

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9. Except as set forth herein and except as required by applicable law, theUncertificated ADSs shall be treated as ADSs issued and outstanding under the terms of the Deposit Agreement (as supplemented by this letter agreement). In the event that, in determining the rights and obligations of parties to the Deposit Agreement(as supplemented by this letter agreement) with respect to any Uncertificated ADSs, any conflict arises between (a) the terms of the Deposit Agreement and (b) the terms hereof, the terms and conditions set forth herein shall be controllingand shall govern the rights and obligations of the parties to the Deposit Agreement pertaining to the Uncertificated ADSs. 

10. This letter agreement shall be interpreted under, and all the rights and obligations hereunder shall be governed by,the laws of the State of New York without regard to the principles of choice of law thereof. 

11. The terms ofthis letter agreement supplement the Deposit Agreement, and are not intended to material prejudice any substantial existing rights of Holders of ADSs and, as a result, notice may, but is not required, to be given of the terms hereof to Holders ofADSs under the Deposit Agreement. 

12. The Company and the Depositary shall make reference to the terms ofthis letter agreement, or attach an executed copy hereof to, the next Registration Statement on Form F-6 filing made with the Securities and Exchange Commission in respect of the ADSs. 

 

CITIBANK, N.A.,

  as Depositary

By:
 
/s/ Ana Maria Carasso
 
Name:
 
Ana Maria Carasso
 
Title:
 
Vice President
 
Date:
 
Oct. 12, 2007

Acknowledgedand Agreed: 

 

Cemex S.A.B. de C.V.

By:
 
/s/ Rodrigo Treviño
 
Name:
 
Rodrigo Treviño
 
Title:
 
Chief Financial Officer
 
Date:
 
 

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