**Exhibit 4.50.1**

*******Execution Version*******

**SUPPLEMENTAL INDENTURE NO. 1**

SUPPLEMENTAL INDENTURE No. 1, dated as of January 19, 2010 by and between CEMEX Finance LLC, a limitedliability company organized and existing pursuant to the laws of the state of Delaware (the “Company”), the Note Guarantors party thereto (the “Note Guarantors”), and The Bank of New York Mellon, as trustee (the“Trustee”). 

**W I T N E S S E T H:**

**WHEREAS**, the Company and the Trustee previously have entered into an indenture, dated as of December 14, 2009(the “Original Indenture”, and as supplemented by this Supplemental Indenture No. 1 and any further amendments or supplements thereto, the “Indenture”), providing for the issuance of 9.50% Senior Secured Notesdue 2016; 

**WHEREAS**, the Indenture provides for, among other things, that, subsequent to the executionof the Original Indenture, the Company and the Trustee may without the consent of holders of the outstanding 9.50% Senior Secured Notes due 2016 enter into one or more indentures supplemental to the Original Indenture to provide for the issuance ofAdditional Notes in accordance with Section 2.14 thereof; 

**WHEREAS**, on November 30, 2009, theSole Manager of the Company has authorized the issuance of up to U.S.$2,500,000,000 (or its equivalent in other currencies) of aggregate principal amount of notes, which includes the Additional Notes; 

**WHEREAS**, each of the Note Guarantors has been duly authorized to issue its Note Guarantee in connection with theAdditional Notes; 

**WHEREAS**, the Company has requested that the Trustee join in the execution of thisSupplemental Indenture No. 1; and 

**WHEREAS**, all things necessary to make this SupplementalIndenture No. 1 a valid agreement of the parties and a valid supplement to the Indenture have been done. 

**NOW, THEREFORE**,**** for and in consideration of the premises and the mutual covenants contained herein and inthe Indenture and for other good and valuable consideration, the receipt and sufficiency of which are herein acknowledged, the Company, the Note Guarantors and the Trustee hereby agree, for the equal and ratable benefit of all Holders, as follows:

**ARTICLE ONE**

DEFINITIONS 

Section 1.01 Defined Terms. All capitalized terms used but not defined herein shall have the meaningsascribed to such terms in the Indenture, as supplemented and amended hereby. All definitions in the Original Indenture shall be read in a manner consistent with the terms of this Supplemental Indenture No. 1. 

**ARTICLE TWO**

ADDITIONAL NOTES 

Section 2.01 The Additional Notes. Pursuant to Section 2.14 of the Original Indenture, the Companyhereby creates and issues $500,000,000 aggregate principal amount of its 9.50% Senior Secured Notes due 2016 (the “Additional Notes”). These Additional Notes will be consolidated to form a single series, and be fully fungible, withthe Company’s outstanding 9.50% Senior Secured Notes due 2016 issued on December 14, 2009, to which the Additional Notes are identical in all terms and conditions except issue date and issue price. Interest on the Additional Notes shallaccrue from December 14, 2009. All Additional Notes issued under the Indenture will, when issued, be considered Notes for all purposes thereunder and will be subject to and take the benefit of all of the terms, conditions and provisions of theIndenture. 

Section 2.02 Execution and Authentication of the Additional Notes. The Trustee shall,pursuant to an Authentication Order, authenticate the Additional Notes. 

**ARTICLE THREE**

MISCELLANEOUS 

Section 3.01. Effect of This Supplemental Indenture No. 1.**This Supplemental Indenture No. 1supplements the Original Indenture and shall be a part, and subject to all the terms, thereof. The Original Indenture, as supplemented and amended by this Supplemental Indenture No. 1, is in all respects ratified and confirmed, and the OriginalIndenture and this Supplemental Indenture No. 1 shall be read, taken and construed as one and the same instrument. All provisions included in this Supplemental Indenture No. 1 supersede any conflicting provisions included in the OriginalIndenture, unless not permitted by law. 

Section 3.02 Governing Law. This Supplemental IndentureNo. 1 shall be governed by, and construed in accordance with, the laws of the State of New York. 

Section 3.03 Effect of Headings. The section headings herein are for convenience only and shall not affectthe construction of this Supplemental Indenture No. 1. 

 

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Section 3.04 Counterparts. The parties may sign any number ofcopies of this Supplemental Indenture No. 1. Each signed copy shall be an original, but all of them shall represent the same agreement. 

Section 3.05 The Trustee. The Trustee shall not be responsible in any manner whatsoever for or in respect ofthe validity or sufficiency of this Supplemental Indenture No. 1 or for or in respect of the recitals contained herein, all of which are made solely by the Company and the Note Guarantors. In entering into this Supplemental IndentureNo. 1, the Trustee shall be entitled to the benefit of every provision of the Indenture relating to the conduct or affecting the liability or affording protection to the Trustee whether or not elsewhere herein so provided. The Company and theNote Guarantors expressly reaffirm and confirm their obligations to indemnify the Trustee in connection with the Indenture and all the actions contemplated hereby, all in accordance with the terms of the Indenture. 

[SIGNATURE PAGE TO FOLLOW IMMEDIATELY] 

 

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**SIGNATURES**

Dated as of January 19, 2010 

 
CEMEX Finance LLC, as IssuerBy: /s/ Hector Medina Name: Hector Medina Title: Attorney-in-Fact
CEMEX, S.A.B. de C.V., as Note Guarantor
By: /s/ Lorenzo H. Zambrano Name: Lorenzo H. Zambrano Title: Attorney-in-Fact
CEMEX México, S.A. de C.V., as Note Guarantor
By: /s/ Rodrigo Treviño Name: Rodrigo Treviño Title: Attorney-in-Fact
Empresas Tolteca de México, S.A.

de C.V., as Note Guarantor
By: /s/ Rodrigo Treviño Name: Rodrigo Treviño Title: Attorney-in-Fact
 

Signature page to Supplemental Indenture No. 1 

CEMEX Concretos, S.A. de C.V., as Note Guarantor
By: /s/ Rodrigo Treviño Name: Rodrigo Treviño Title: Attorney-in-Fact
New Sunward Holding B.V., as Note Guarantor
By: /s/ Humberto Lozano Name: Humberto Lozano Title: Attorney-in-Fact
CEMEX España, S.A., as Note Guarantor
By: 
/s/ Humberto Lozano
 Name: Humberto Lozano Title: Attorney-in-Fact
CEMEX Corp., as Note Guarantor
By: /s/ Humberto Lozano Name: Humberto Lozano Title: Attorney-in-Fact
 

Signature page to Supplemental Indenture No. 1 

THE BANK OF NEW YORK

MELLON, as Trustee

By:
 
/s/ Joanne Adamis
 
Name: Joanne Adamis
 
Title: Vice President

 

Signature page to Supplemental Indenture No. 1