Exhibit 4.19





                    Empresas Tolteca de Mexico, S.A. de C.V.
                           Ave. Constitucion 444 Pte.
                             Monterrey, N.L. 64000
                                     Mexico



Amendment No. 1 to Confirmation
dated December 13, 2002
between Empresas Tolteca
de Mexico, S.A. de C.V. and
JPMorgan Chase Bank (Transaction Reference No. _______________)



                                                      October 15, 2003

Ladies and Gentlemen:

Reference is hereby made to (i) the ISDA Master Agreement dated as of December
13, 1999 and the Confirmation thereunder dated December 13, 2002 (the
CONFIRMATION), each between you and us, and the Calculation Agency and
Interbank Agreement between you, us, Citibank, N.A. as Calculation Agent and
the other Participants listed therein dated as of December 13, 1999, as amended
by Amendment No. 1 thereto dated as of December 13, 2002 (as amended, the
CALCULATION AGENCY AND INTERBANK AGREEMENT and, together with the Confirmation,
the FORWARD TRANSACTION AGREEMENT), (ii) an Escrow Agreement dated as of
September 26, 2003 (the ESCROW AGREEMENT) between you, Cemex, S.A. de C.V., us,
Citibank, N.A., as Escrow Agent, Citibank, N.A., acting through its Emerging
Markets and Sales Group, as Designated Selling Shareholder, and the other
depositors referred to therein and (iii) a Share Purchase Agreement to be
entered into (the ESPANA SHARE PURCHASE AGREEMENT) between you and us, pursuant
to which you will agree to sell, and we will agree to buy, the Specified Number
of Espana Shares. Capitalized terms used but not defined herein shall have the
meanings assigned to them in the Confirmation, or if not defined therein, in
the Calculation Agency and Interbank Agreement. For purposes of the
Confirmation and the Calculation Agency and Interbank Agreement, references
herein to "Espana" shall be deemed to be references to "Valenciana".

Notwithstanding the provisions of Paragraphs 5 and 6 of the First Confirmation,
you and we agree as follows:

1. In the event that, prior to October 30, 2003, (a) Bank enters into one or
more underwriting agreements with Cemex, J.P. Morgan Securities Inc. (the
UNDERWRITER), other underwriters specified therein and the other Participants
providing for the sale of Cemex ADS and/or Ordinary Participation Certificates
and (b) Underwriter and Cemex deliver the Initial Closing Delivery Instructions
(as defined in the Escrow Agreement), the Transaction will terminate with
respect to the Specified Number of Cemex ADS and the Specified Number of Espana
Shares on October 29, 2003 (such date, for purposes hereof, the NET CASH
SETTLEMENT TERMINATION DATE). In the event that less than the Specified Number
of Cemex ADS are sold in connection with the initial closing of the Global
Offering (as defined in the Escrow Agreement) or in connection with the
exercise by the Underwriter of the Over-Allotment Option (as defined in the
Escrow Agreement), we agree to purchase, or cause a third-party to purchase,
the remaining Specified Number of Cemex ADS for settlement on or prior to the
Net Cash Settlement Termination Date.

         On the Net Cash Settlement Termination Date, (a) if the Final Payment
Amount is a positive number, Bank shall pay to Counterparty the Final Payment
Amount and (b) if the Final Payment Amount is a negative number, Counterparty
shall pay the absolute value of the Final Payment Amount to Bank.

For purposes of this paragraph 1,

(i)      the FINAL PAYMENT AMOUNT shall be an amount equal to (a) the Net Cash
         Settlement Amount MINUS (b) the sum of all Advance Payments (as
         defined below) made to Counterparty;

(ii)     the NET CASH SETTLEMENT AMOUNT shall be an amount equal to (a) the
         Cemex ADS Total Purchase Price PLUS (b) the Espana Value on the
         Valuation Date immediately preceding the Net Cash Settlement
         Termination Date MULTIPLIED BY the Specified Number of Espana Shares
         MINUS (c) the Adjusted Forward Payment Amount as of the Net Cash
         Settlement Termination Date MINUS (d) the sum of all Transfer Payments
         (as defined below) made to Bank in accordance with the Escrow
         Agreement;

(iii)    the CEMEX ADS TOTAL PURCHASE PRICE shall be an amount determined by
         (1) multiplying (A) the number of Cemex ADS sold (or the number of
         Cemex ADS representing Ordinary Participation Certificates sold) in
         connection with each sale by Bank of a portion of the Specified Number
         of Cemex ADS (or the underlying Ordinary Participation Certificates)
         by (B) the price at which such Cemex ADS were sold (or, in the case of
         a sale of Ordinary Participation Certificates, the price at which
         Ordinary Participation Certificates represented by one Cemex ADS were
         sold (converted at the exchange rate at which the proceeds from such
         sale are converted to USD in accordance with the Escrow Agreement))
         and (2) summing the amounts determined pursuant to clause (1); and

(iv)     the amounts transferred to Bank in accordance with the Escrow
         Agreement (each such transfer, a TRANSFER PAYMENT) in connection with
         each sale by Bank of a portion of the Specified Number of Cemex ADS on
         and after the initial closing of the Global Offering shall be deemed
         to be Advanced Forward Payment Amounts for purposes of determining the
         Adjusted Forward Payment Amount, except that the FV2 with respect to
         such amounts shall be determined using a Swap Rate based on
         USD-LIBOR-BBA for deposits with a maturity closest to the period of
         time from the date on which such amount is transferred to Bank to the
         Termination Date.

Upon payment of the Final Payment Amount, (i) Bank shall have no obligation
under the Forward Transaction Agreement to deliver the Specified Number of
Cemex ADS and the Specified Number of Espana Shares to Counterparty and
Counterparty shall have no obligation to pay to Bank the Adjusted Forward
Payment Amount and (ii) the Forward Transaction Agreement and any voting
agreement entered into by or on behalf of the Bank with respect to the Cemex
ADS and/or the Espana Shares shall be terminated.

2.  In connection with each sale by Bank of Cemex ADS from and including the
initial closing of the Global Offering to but excluding the Net Cash Settlement
Termination Date, Bank agrees to advance to Counterparty (each such advance, an
ADVANCE PAYMENT), as specified in the Escrow Agreement, an amount equal to the
amount by which the aggregate proceeds from such sale and all prior sales of
Cemex ADS exceed the Adjusted Forward Payment Amount on the date of such sale.

3.  Counterparty hereby agrees to indemnify Bank, upon demand, for losses or
expenses incurred by Bank in the event that, in connection with a proposed sale
of Cemex ADS, Bank terminates any agreement pursuant to which it has hedged its
position under the Forward Transaction Agreement in the Eurodollar market and
such sale (whether as the result of a Settlement Disruption Event or otherwise)
does not occur.

We are seeking to obtain the same agreements from the other Participants, and
this letter shall not become effective until each other Participant has
delivered a signed letter in substantially the same form as this letter.

This letter shall be construed in accordance with, and this letter and all
matters arising out of or relating in any way whatsoever to this letter
(whether in contract, tort or otherwise) shall be governed by, the law of the
State of New York. Except as provided herein, the Forward Transaction Agreement
remains unchanged.

Please indicate your agreement to the terms of this letter by executing this
letter below and returning it to us.

                                     Very truly yours,

                                     Empresas Tolteca de Mexico, S.A. de C.V.



                                     By: /s/ Rodrigo Trevino
                                         ______________________________
                                         Name:  Rodrigo Trevino
                                         Title: Chief Financial Officer



Accepted and Agreed:

JPMorgan Chase Bank



By: /s/ Peter Turk
    ___________________________
    Name:  Peter Turk
    Title: Managing Director