EXHIBIT 4.20.1

                                AMENDMENT NO. 1

                          TO ASSET PURCHASE AGREEMENT


         AMENDMENT NO. 1 TO ASSET PURCHASE AGREEMENT, dated as of March 31,
2005 (this "Amendment"), by and between CEMEX, Inc., a Louisiana corporation
("Seller"), and Votorantim Participacoes S.A., a corporation (sociedade
anonima) organized under the laws of the Federative Republic of Brazil
("Purchaser"). Capitalized terms used herein but not otherwise defined shall
have the meaning ascribed to such terms in the Purchase Agreement (as defined
below).

                                  WITNESSETH:

         WHEREAS, Seller and Purchaser have entered into that certain Asset
Purchase Agreement, dated as of February 4, 2005 (the "Purchase Agreement");

         WHEREAS, Section 10.8 of the Purchase Agreement provides that the
Purchase Agreement may be amended by the parties thereto by an instrument in
writing signed by Purchaser and Seller; and

         WHEREAS, the Closing has not occurred and Seller and Purchaser wish
to amend the Purchase Agreement as set forth below.

         NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements contained in the Purchase Agreement and this
Amendment, and intending to be legally bound hereby, Seller and Purchaser
hereby agree as follows:

                                  ARTICLE I

                   AMENDMENTS, ACKNOWLEDGEMENT AND COVENANTS

         SECTION 1.1 Amendments to Article VI.

                  (a) Article VI of the Purchase Agreement (entitled
"Covenants") is hereby amended by adding the following new Section 6.21:

         Section 6.21. Toledo Supplemental Sublease.

                  (a) As set forth on Section 2.2(a)(ii) of the Seller
         Disclosure Schedule, that certain Sublease Agreement, dated August 1,
         1986 (the "Toledo Sublease"), among Toledo-Lucas County Port
         Authority ("TCPA"), Medusa Corporation ("Medusa"), and Merce
         Industries, Incorporated ("Merce") constitutes an Assumed Contract.
         TCPA, Medusa and Merce also entered into a certain Supplemental
         Sublease Agreement, dated as of December 1, 1986 (the "Toledo
         Supplemental Sublease") to (i) provide for the issuance of certain
         industrial development revenue bonds (as defined in the Supplemental
         Sublease, the "1986 Series Bonds") to fund certain improvements (as
         defined in the Supplemental Sublease, the "Project") on the property
         subleased by Medusa pursuant to the Toledo Sublease, (ii) provide for
         the payment of "additional rent" to the Authority for payment of
         principal, interest and any premium on the 1986 Series Bonds and
         (iii) set forth certain other provisions governing the use by Medusa
         of, and rights of Medusa with respect to, the Project. Except to the
         extent hereinafter provided in this Section 6.21, the Toledo
         Supplemental Sublease and the rights of Seller thereunder constitute
         an Excluded Asset, and the obligations of Seller under the Toledo
         Supplemental Sublease constitute an Excluded Liability. The rights
         and obligations set forth in Article III and Sections 4.7, 4.8, 5.1,
         5.3 and 6.5 (to the extent not relating to Purchaser's use of the
         property subject to the Toledo Sublease and the Toledo Supplemental
         Sublease) and Section 6.9 (with respect to the second sentence) of
         the Toledo Supplemental Sublease (the "Bond Rights and Obligations")
         shall be exercisable by, and be a burden upon, only Seller, and shall
         not run to the benefit or burden (as the case may be) of Purchaser.
         Seller shall exercise and/or exploit all of its rights and options
         under the Toledo Supplemental Sublease only as reasonably directed by
         Purchaser or Purchaser's designated Affiliate (except that Seller may
         exercise any rights included within the Bond Rights and Obligations
         in its sole discretion to the extent such exercise does not
         materially impair Purchaser's use of the property leased pursuant to
         the Toledo Sublease and the Toledo Supplemental Sublease); provided,
         that, except in cases of gross negligence or willful misconduct on
         the part of Seller (or its officers, employees, agents or
         representatives), Purchaser shall be responsible, and shall
         indemnify, defend and hold harmless Seller hereunder from, against,
         for any liability or Damages to the extent incurred by Seller as a
         result of such direction. If and solely to the extent Seller
         preserves its rights under, and the benefits of, the Toledo
         Supplemental Sublease for the enjoyment of Purchaser and complies
         with the obligations included within the Bond Rights and Obligations,
         Purchaser shall accept at the Closing the burdens and perform the
         obligations under the Supplemental Sublease (other than the
         obligations included within the Bond Rights and Obligations) as
         subcontractor of Seller to the extent such burdens and obligations
         would have constituted an Assumed Liability if the Toledo
         Supplemental Sublease constituted an Assumed Contract.

                  (b) Upon the satisfaction of all of Seller's Bond Rights and
         Obligations, each of Seller and Purchaser shall cooperate and use
         commercially reasonable efforts obtain the necessary consents and
         approvals in connection with the assignment of the Toledo
         Supplemental Sublease to Purchaser (in form and substance reasonably
         acceptable to Purchaser and Seller); provided, however, that neither
         Seller nor Purchaser shall have any obligation to give any guarantee
         or other consideration in connection with any such consent or
         approval. Upon receipt of such consent or approval of such
         assignment, Purchaser shall thereupon agree to assume and perform all
         Liabilities arising under the Toledo Supplemental Sublease after the
         date of such consent, at which time the Toledo Supplemental Sublease
         shall be deemed a Purchased Asset and the Liabilities assumed
         thereunder shall be deemed Assumed Liabilities, without payment of
         any further consideration.

                  (c) This Section 6.21 shall survive the Closing until the
         expiration or earlier termination of the Toledo Supplemental
         Sublease, unless such earlier termination results from a default by
         either party with respect to its obligations set forth in this
         Section 6.21.

                  (b) Miller Termination Fee. Section 6.13(b) to the Purchase
Agreement is hereby amended by deleting it in its entirety and substituting in
lieu thereof the following sentence: Seller shall pay the CDN$750,000 fee
required to be paid by CMC pursuant to Section 11.2 of the Miller Supply
Agreement.

         SECTION 1.2 Acknowledgement. Notwithstanding the provisions of
Section 6.8 of the Purchase Agreement (entitled "Transition Services"), Seller
shall not provide Purchaser, or its designated Affiliate, any Payroll
Services.

         SECTION 1.3 Waivers.

                  (a) Owen Sound Lease. Each of Purchaser and Seller hereby
waives the requirement under Section 3.2(c) that the third party consent
relating to Item 3 set forth in Section 3.2(c) of the Seller Disclosure
Schedule (Lease for 38.65 square meters of wharf space in the Public Harbour
of Owen Sound, Ontario, Canada; dated August 28, 1987, by and between Her
Majesty, the Queen in right of Canada, represented by the Minister of
Transport as lessor; and Miller Paving Company as tenant, and subsequently
assigned to Miller Terminals Limited by the Assignment by Tenant dated March
27, 1990, and consented to by the Department of Transport Consent to
Assignment dated May 3, 1990; as amended by the Supplemental Agreement dated
as of November 1, 1989) be obtained prior to the Closing.

                  (b) Employment Offers. Seller hereby waives the requirement
under Section 7.1 of the Purchase Agreement that Purchaser makes its
employment offers to Facility Employees at least three days before the Closing
Date.

         SECTION 1.4 Challenger Documents.

                  (a) Each of Purchaser and Seller hereby waives the
requirement under Section 3.2(c) that the third party consents relating to
Items 1 and 2 set forth in Section 3.2(c) of the Seller Disclosure Schedule
((1) Time Charter Party dated May 31, 2002 between Wilmington Trust Company,
not in its individual capacity but solely as owner trustee under an Owner
Amended and Restated Trust Agreement dated May 28, 2002 between Wilmington
Trust Company as owner trustee and Citicorp Railmark, Inc. as owner
participant and CEMEX, Inc. as time charterer (the "Time Charter") and (2)
Participation Agreement dated as of May 28, 2002 among Cemex, Inc., as
charterer, Compania Valenciana de Cementos Portland, S.A., as guarantor,
Citicorp Railmark, Inc., as owner participant, and Wilmington Trust Company,
not in its individual capacity, except as expressed therein, but solely as
owner trustee (the "Participation Agreement", and together with the Time
Charter, the "Challenger Documents")) be obtained prior to the Closing.

                  (b) Both Purchaser and Seller acknowledge that the
Challenger Documents shall be Unassigned Contracts as of the Closing Date.
Notwithstanding Section 6.3(b) of the Purchase Agreement, Seller and Purchaser
covenant and agree to use, and to cause their respective Affiliates to use,
commercially reasonable efforts to obtain the consent, approval or
authorization to the assignment of the Challenger Documents as promptly after
the Closing as possible; provided, however, that Seller shall have no
obligation to give any guarantee or other consideration in connection with any
such consent, authorization or approval. During the time between the Closing
and the receipt of such consent, approval or authorization, subject to the
terms of the Challenger Documents, Seller shall use commercially reasonable
efforts in any lawful and economically reasonable arrangement to provide
Purchaser with Seller's entire interest in the benefits under each of the
Challenger Documents. Seller shall exercise or exploit its rights and options
under Challenger Documents only as reasonably directed by Purchaser. Except in
cases of gross negligence or willful misconduct on the part of Seller or its
Affiliates (or their respective officers, employees, agents or
representatives), Purchaser shall be responsible, and shall indemnify, defend
and hold harmless Seller and its Affiliates in accordance with Article VIII of
the Purchase Agreement from and against any and all liabilities or Damages
incurred by Seller or any of its Affiliates arising on or after the Closing
Date in connection with or arising out of the Challenger Documents. If and
solely to the extent Seller provides to Purchaser, as a sub-charterer, the
rights and benefits under the Challenger Documents, Purchaser shall accept the
burdens and perform the obligations under the Challenger Documents as
sub-charterer of Seller or its Affiliates to the extent such burdens and
obligations would have constituted an Assumed Liability if the Challenger
Documents had been transferred to Purchaser at the Closing. When the other
party(ies) to the Challenger Documents subsequently consent to the assignment
of the Challenger Documents to Purchaser, Purchaser shall thereupon agree to
assume and perform all Liabilities arising thereunder after the date of such
consent (in accordance with the terms of the Challenger Assignment Agreement
(as defined below)), at which time each of the Challenger Documents shall be
deemed a Purchased Asset and the Liabilities so assumed thereunder shall be
deemed Assumed Liabilities, without the payment of further consideration.

                  (c) Purchaser shall also reimburse Seller and it Affiliates
for any and all costs and expenses incurred by Seller in its fulfillment of
obligations under the Challenger Documents on and after the Closing Date
(including, but not limited to, all costs associated with insuring the
Challenger in accordance with the Challenger Documents during such time).
Purchaser shall execute a wire transfer to Seller's account in the amount of
reimbursement requested by Seller within three business days of receipt from
Seller of the request.

                  (d) Seller and Purchaser hereby acknowledge and agree that
this provision is subject to and subordinate to the terms of the Time Charter,
and Purchaser hereby acknowledges that it has been provided with a copy of the
Time Charter and is fully familiar with the terms thereof.

                  (e) Seller and Purchaser hereby agree that neither Seller
nor Purchaser shall amend the terms of the Assignment, Assumption and
Amendment Agreement in the form attached hereto as Exhibit A (the "Challenger
Assignment Agreement") without the written consent of the other party (which
consent shall not be unreasonably, withheld, conditioned or delayed).

         SECTION 1.5 Consent Order. Seller represents and warrants that it has
paid and satisfied its financial assurance obligations under Section 2.7 of
that certain Consent Order identified as WHMD Order No. 115-17-02, between
Seller and the State of Michigan Department of Environmental Quality, (the
"Consent Order"), through October 24, 2005. From and after the Closing, the
parties shall reasonably cooperate to ensure the obligations under the Consent
Order are satisfied.

                                  ARTICLE II

                                REPRESENTATIONS

         Each of Seller and Purchaser hereby represents to the other that (a)
it has full organizational power and authority to execute and deliver this
Amendment and to consummate the transactions contemplated hereby, (b) the
execution and delivery of this Amendment by such party have been duly and
validly authorized by all necessary corporate action on the part of such party
and (c) this Amendment has been duly and validly executed and delivered by
such party and constitutes a valid and binding obligation of such party,
enforceable against such party in accordance with its terms, except that such
enforceability (i) may be limited by bankruptcy, insolvency, moratorium or
other similar laws affecting or relating to the enforcement of creditors'
rights generally and (ii) is subject to general principles of equity and the
discretion of the court before which any proceedings seeking injunctive relief
or specific performance may be brought.

                                 ARTICLE III

                                 MISCELLANEOUS

         SECTION 3.1 Headings. The headings contained in this Amendment are
for reference purposes only and shall not affect in any way the meaning or
interpretation of this Amendment.

         SECTION 3.2 Counterparts. This Amendment may be executed in two or
more counterparts, each of which when executed shall be deemed to be an
original but all of which shall constitute one and the same agreement.

         SECTION 3.3 Governing Law. This Amendment shall be governed,
construed and enforced in accordance with the Laws of the State of Delaware
without giving effect to the principles of conflicts of law thereof.

         SECTION 3.4 No Other Effect on the Purchase Agreement. Except as
modified by this Amendment, all of the terms of the Purchase Agreement are
hereby ratified and confirmed and shall remain in full force and effect.





         IN WITNESS WHEREOF, Seller and Purchaser have caused this Amendment
to be signed by their respective officers thereunto duly authorized as of the
date first written above.

                                            VOTORANTIM PARTICIPACOES S.A.


                                            By:   /s/ Alexandre S. Dambrosio
                                                ------------------------------
                                            Name:  Alexandre S. Dambrosio
                                            Title: Attorney-In-Fact


                                            By:  /s/ Marcelo Martins
                                                ------------------------------
                                            Name:  Marcelo Martins
                                            Title: Attorney-In-Fact


                                            CEMEX, INC.


                                            By:   /s/ Jill Simeone
                                                ------------------------------
                                            Name:  Jill Simeone
                                            Title: Assistant Secretary

                                            By:   /s/ Philippe Gastone
                                                ------------------------------
                                            Name:  Philippe Gastone
                                            Title: Vice President