<PAGE>

                                                                    EXHIBIT 10.2

                                                                  EXECUTION COPY

================================================================================

                                                          INVESTMENT NUMBER 9902

                              AMENDED AND RESTATED
                                 LOAN AGREEMENT

                                     BETWEEN

                           GW SERVICIOS, S.A. DE C.V.

                                       AND

              COMPANIA DE FERROCARRILES CHIAPAS-MAYAB, S.A. DE C.V.

                                       AND

                        INTERNATIONAL FINANCE CORPORATION

                             DATED DECEMBER 5, 2000

                    AMENDED AND RESTATED AS OF MARCH 15, 2005

================================================================================

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
Article or
  Section                           Item                                                         Page No.
-----------                         ----                                                         --------
<S>                                                                                              <C>
ARTICLE I...................................................................................         2

DEFINITIONS AND INTERPRETATION..............................................................         2

      Section 1.01.  General Definitions....................................................         2
      Section 1.02.  Financial Definitions..................................................        16
      Section 1.03.  Financial Calculations.................................................        20
      Section 1.04.  Interpretation.........................................................        21
      Section 1.05.  Business Day Adjustment................................................        21

ARTICLE II..................................................................................        21

THE PROJECT, PROJECT COST AND FINANCIAL PLAN................................................        21

      Section 2.01.  The Project............................................................        21
      Section 2.02.  Project Cost and Financial Plan........................................        21

ARTICLE III.................................................................................        23

THE LOAN....................................................................................        23

      Section 3.01.  The Loan...............................................................        23
      Section 3.02.  [reserved].............................................................        23
      Section 3.03.  Interest...............................................................        23
      Section 3.04.  Change in Interest Period..............................................        24
      Section 3.05.  Default Rate Interest..................................................        25
      Section 3.06.  Repayment..............................................................        25
      Section 3.07.  Prepayment.............................................................        26
      Section 3.08.  Fees...................................................................        27
      Section 3.09.  Currency and Place of Payments.........................................        29
      Section 3.10.  Allocation of Partial Payments.........................................        29
      Section 3.11.  Increased Costs........................................................        30
      Section 3.12.  Unwinding Costs........................................................        30
      Section 3.13.  [reserved].............................................................        30
      Section 3.14.  Taxes..................................................................        30
      Section 3.15.  Expenses...............................................................        31
      Section 3.16.  Illegality of Participation............................................        32
      Section 3.17.  Notes..................................................................        33

ARTICLE IV..................................................................................        33
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                                     - ii -

<TABLE>
<S>                                                                                                 <C>
REPRESENTATIONS AND WARRANTIES..................................................................    33

      Section 4.01.  Representations and Warranties.............................................    33
      Section 4.02.  IFC Reliance...............................................................    36

ARTICLE V.......................................................................................    36

CONDITIONS OF EFFECTIVENESS.....................................................................    36

      Section 5.01.  Conditions of Effectiveness................................................    36
      Section 5.02   IFC Notice; Amendment and Restatement; Conditions for IFC's Benefit........    38

ARTICLE VI......................................................................................    38

PARTICULAR COVENANTS............................................................................    38

      Section 6.01.  Affirmative Covenants......................................................    38
      Section 6.02.  Negative Covenants Relating to the Borrower................................    41
      Section 6.03.  Negative Covenants Relating to the Project Company.........................    45
      Section 6.04.  Reporting Requirements.....................................................    49
      Section 6.05.  Insurance..................................................................    53

ARTICLE VII.....................................................................................    55

EVENTS OF DEFAULT...............................................................................    55

      Section 7.01.  Acceleration after Default.................................................    55
      Section 7.02.  Events of Default..........................................................    56
      Section 7.03.  Bankruptcy.................................................................    59

ARTICLE VIII....................................................................................    59

MISCELLANEOUS...................................................................................    59

      Section 8.01.  Saving of Rights...........................................................    59
      Section 8.02.  Notices....................................................................    60
      Section 8.03.  English Language...........................................................    61
      Section 8.04.  Term of Agreement..........................................................    61
      Section 8.05.  Applicable Law and Jurisdiction............................................    62
      Section 8.06.  Disclosure of Information..................................................    64
      Section 8.07.  Successors and Assigns.....................................................    64
      Section 8.08.  Amendments, Waivers and Consents...........................................    64
      Section 8.09.  Counterparts...............................................................    64

ARTICLE IX......................................................................................    64

THE MERGER......................................................................................    64
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                                    - iii -

<TABLE>
<S>                                                                                                 <C>
      Section 9.01.  Conditions Precedent of the Merger.........................................    64
      Section 9.02.  Acknowledgment of the Borrower.............................................    65

ANNEX A.........................................................................................    67

[RESERVED]......................................................................................    67

ANNEX B.........................................................................................    68

INSURANCE REQUIREMENTS..........................................................................    68

ANNEX C.........................................................................................    69

[RESERVED]......................................................................................    69

SCHEDULE 1......................................................................................    70

FORM OF CERTIFICATE OF INCUMBENCY AND AUTHORITY.................................................    70

SCHEDULE 2......................................................................................    72

FORM OF CERTIFICATION OF REPRESENTATIONS AND WARRANTIES.........................................    72

SCHEDULE 3......................................................................................    74

FORM OF NOTICE OF EFFECTIVENESS.................................................................    74

SCHEDULE 4......................................................................................    75

FORM OF SERVICE OF PROCESS LETTER...............................................................    75

SCHEDULE 5......................................................................................    77

[RESERVED]......................................................................................    77

SCHEDULE 6......................................................................................    78

FORM OF LETTER TO BORROWER'S AUDITORS...........................................................    78

SCHEDULE 7......................................................................................    80

FORM OF BORROWER'S CERTIFICATION ON DISTRIBUTION OF DIVIDENDS...................................    80
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                                     - iv -

<TABLE>
<S>                                                                                                 <C>
SCHEDULE 8......................................................................................    82

[RESERVED]......................................................................................    82

SCHEDULE 9......................................................................................    83

INFORMATION TO BE INCLUDED IN ANNUAL REVIEW OF OPERATIONS.......................................    83

SCHEDULE 10.....................................................................................    85

FORM OF ANNUAL MONITORING REPORT................................................................    85

SCHEDULE 11.....................................................................................    89

FORM OF NOTES...................................................................................    89
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                       AMENDED AND RESTATED LOAN AGREEMENT

AMENDED AND RESTATED LOAN AGREEMENT (this "Agreement"), dated December 5, 2000,
as amended and restated as of March 15, 2005, between:

      (1)   GW SERVICIOS, S.A. DE C.V., a sociedad anonima de capital variable
            organized and existing under the laws of the United Mexican States
            (the "Borrower"; provided, however, that after the Merger (as
            defined below) the "Borrower" shall mean the surviving entity);

      (2)   COMPANIA DE FERROCARRILES CHIAPAS-MAYAB, S.A. DE C.V., a sociedad
            anonima de capital variable organized and existing under the laws of
            the United Mexican States (the "Project Company"); and

      (3)   INTERNATIONAL FINANCE CORPORATION, an international organization
            established by Articles of Agreement among its member countries
            including the United Mexican States ("IFC").

      WHEREAS:

      (A) Under the terms of the original loan agreement dated December 5, 2000
between the Borrower, the Project Company and IFC (the "Original IFC Loan
Agreement"), IFC made (i) an A loan to the Borrower in the principal amount of
ten million five hundred thousand Dollars ($10,500,000) of which the principal
amount of seven million five hundred thousand Dollars ($7,500,000) is currently
outstanding (which amount shall be reduced to seven million two hundred eighty
thousand eight hundred thirty-six Dollars ($7,280,836) after prepayment of the
amount set forth in Section 5.01(b)) and (ii) a B Loan to the Borrower in the
principal amount of ten million Dollars ($10,000,000), of which the principal
amount of six million six hundred sixty-six thousand six hundred sixty eight
Dollars ($6,666,668) is currently outstanding (which amount shall be reduced to
six million four hundred fifty-seven thousand nine hundred forty-one Dollars
($6,457,941) after prepayment of the amount set forth in Section 5.01(c)).

      (B) The Borrower, the Project Company and IFC desire to modify the
Original IFC Loan Agreement in order to, among other things, extend the
repayment term of the IFC Loan and make other changes as more fully set forth
herein.

      (C) In order to accomplish the foregoing, the Borrower, the Project
Company and IFC are amending and restating in its entirety the Original IFC Loan
Agreement as set forth herein.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 2 -

                                    ARTICLE I

                         DEFINITIONS AND INTERPRETATION

      Section 1.01. General Definitions. Wherever used in this Agreement, the
following terms have the meanings opposite them:

"A Loan"                       the loan specified in Section 3.01(a) (The Loan)
                               or, as the context requires, its principal amount
                               from time to time outstanding;

"A Loan Disbursement"          any disbursement of the A Loan;

"A Loan Interest Rate"         for any Interest Period, the rate at which
                               interest is payable on the A Loan during that
                               Interest Period, determined in accordance with
                               Section 3.03 (Interest) and, if applicable,
                               Section 3.04 (Change in Interest Period);

"Accounting Principles"        United States Generally Accepted Accounting
                               Principles (US-GAAP) promulgated by the Financial
                               and Accounting Standards Board, together with its
                               pronouncements thereon from time to time, and
                               applied on a consistent basis;

"Affiliate"                    any Person directly or indirectly controlling,
                               controlled by or under common control with, the
                               Borrower or the Project Company (for purposes of
                               this definition, "control" means the power to
                               direct the management or policies of a Person,
                               directly or indirectly, whether through the
                               ownership of shares or other securities, by
                               contract or otherwise, provided that the direct
                               or indirect ownership of ten per cent (10%) or
                               more of the voting share capital of a Person is
                               deemed to constitute control of that Person, and
                               "controlling" and "controlled" have corresponding
                               meanings);

"Asset Purchase
  Agreement"                   the Asset Purchase Agreement dated as of June 18,
                               1999 between the Project Company and GoM;

"Auditors"                     PricewaterhouseCoopers L.L.P, or such other firm
                               that each of the Borrower and the Project Company
                               appoints from time to time as its auditors
                               pursuant to Section 6.01 (d) (Affirmative
                               Covenants);

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 3 -

"Authority"                    any national, supranational, regional or local
                               government or governmental, administrative,
                               fiscal, judicial, or government-owned body,
                               department, commission, authority, tribunal,
                               agency or entity, or central bank (or any Person,
                               whether or not government owned and howsoever
                               constituted or called, that exercises the
                               functions of a central bank);

"Authorization"                any consent, registration, filing, agreement,
                               notarization, certificate, license, approval,
                               permit, authority or exemption from, by or with
                               any Authority, whether given by express action or
                               deemed given by failure to act within any
                               specified time period and all corporate,
                               creditors' and shareholders' approvals or
                               consents;

"Authorized
Representative"                any natural person who is duly authorized by the
                               Borrower or the Project Company to act on its
                               behalf for the purposes specified in, and whose
                               name and a specimen of whose signature appear on,
                               the Certificate of Incumbency and Authority most
                               recently delivered by the Borrower and the
                               Project Company to IFC;

"B Loan"                       the loan specified in Section 3.01(b) (The Loan)
                               or, as the context requires, its principal amount
                               from time to time outstanding;

"B Loan Disbursement"          any disbursement of the B Loan;

"B Loan Interest Rate"         for any Interest Period, the rate at which
                               interest is payable on the B Loan during that
                               Interest Period, determined in accordance with
                               Section 3.03 (Interest) and, if applicable,
                               Section 3.04 (Change in Interest Period);

"Business Day"                 a day when banks are open for business in
                               New York, New York or, solely for the purpose of
                               determining the applicable Interest Rate other
                               than pursuant to Section 3.03 (d)(ii)(Interest),
                               London, England;

"CAP"                          the Corrective Action Plan dated August 4, 2000,
                               prepared by the Sponsor on behalf of the Project
                               Company;

"Certificate of Incumbency
and Authority"                 a certificate provided to IFC by each of the
                               Borrower and the Project Company in the form of
                               Schedule 1;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 4 -

"Charter"                      with respect to any Person, the estatutos
                               sociales and any other constitutive document of
                               such Person;

"Concession Agreement"         the Concession Agreement dated August 26, 1999
                               between the Project Company and GoM;

"Concession Termination
Compensation Assignment
Notice"                        a notice to be filed with the GoM by the Project
                               Company, pursuant to which the Project Company
                               shall assign to the Senior Lenders any concession
                               termination compensation payments payable to the
                               Project Company by the GoM;

"Credit Line Agreement"        the Credit Line Agreement dated the date hereof,
                               between the Borrower and the Project Company;

"Derivative Transaction"       any swap agreement, cap agreement, collar
                               agreement, futures contract, forward contract or
                               similar arrangement with respect to interest
                               rates, currencies or commodity prices;

"Disbursement"                 any disbursement of the A Loan, the B Loan or the
                               FMO Loan or all of the above, as the context
                               requires;

"Dollars" and "$"              the lawful currency of the United States of
                               America;

"Environmental
Assessment Report"             the Baseline Environmental Assessment report
                               dated January 12, 1999, relating to the Project
                               Company, prepared by TRC Environmental
                               Corporation;

"Environmental, Health
and Safety Guidelines"         the IFC Environmental, Health and Safety
                               Guidelines for Railway Systems, dated November
                               20, 1995, a copy of which has been delivered to,
                               and receipt of which has been acknowledged by
                               letter dated February 10, 2000 by, each of the
                               Borrower and the Project Company and which is
                               incorporated herein by reference;

"Environmental
and Social Policies"           the IFC Policy on Environmental Assessment (OP
                               4.01), dated October 1998, the IFC Policy on Pest
                               Management (OP 4.09), dated June 1990, the World
                               Bank Policy on Involuntary Resettlement (OD
                               4.30), dated June 1990, the World Bank Policy
                               Note on Management of Cultural Property (OPN
                               11.03), dated September 1986, and the IFC

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 5 -

                               Policy Statement on Forced Labor and Harmful
                               Child Labor, dated March 1998, copies of which
                               have been delivered to, and receipt of which has
                               been acknowledged by letter dated February 10,
                               2000 by, each of the Borrower and the Project
                               Company and which are incorporated herein by
                               reference;

"Event of Default"             any one of the events specified in Section 7.02
                               (Events of Default);

"Existing Deficiency
Loan Agreements"               collectively, the Deficiency Loan Agreement
                               entered into among the Borrower, the Project
                               Company and the Sponsor on December 17, 2004 and
                               the Deficiency Loan Agreement entered into among
                               the same parties on September 21, 2004;

"Financial Plan"               the proposed sources of financing for the Project
                               set out in Section 2.02 (b) (Project Cost and
                               Financial Plan);

"Financial Support
Agreement"                     the agreement entitled "Financial Support
                               Agreement" dated December 5, 2000, as amended and
                               restated as of the date hereof, among the
                               Borrower, the Project Company, the Sponsor and
                               the Senior Lenders;

"Financial Year"               the accounting year of each of the Borrower and
                               the Project Company commencing each year on
                               January 1 and ending on the following December
                               31, or such other period as the Borrower and the
                               Project Company, with IFC's consent, from time to
                               time designate as their accounting year;

"FMO"                          Nederlandse Financierings-Maatschappij voor
                               Ontwikkelingslanden N.V., a limited liability
                               company organized under the laws of The
                               Netherlands ("FMO");

"FMO Disbursement"             a Disbursement of the FMO Loan;

"FMO Guarantee"                the Guarantee Agreement dated December 5, 2000
                               between the Project Company and FMO;

"FMO Loan"                     the loan specified in Section 3.01 of the FMO
                               Loan Agreement or, as the context requires, its
                               principal amount from time to time outstanding;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 6 -

"FMO Loan Agreement"           the Loan Agreement dated December 5, 2000, as
                               amended and restated as of the date hereof, among
                               the Borrower, the Project Company and FMO;

"GoM"                          the Government of Mexico;

"GoM Letter"                   a letter from the GoM to the Project Company,
                               inter alia, (i) consenting to the creation of the
                               Security, (ii) approving the new ownership
                               structure of the Project, (iii) confirming the
                               right of the Senior Lenders to appoint a new
                               operator upon the occurrence of an Event of
                               Default pursuant to Article 18 of the Railroad
                               Law, and (iv) agreeing to notify the Senior
                               Lenders in the event a notification, fine,
                               warning or other action or communication from the
                               GoM is taken with respect to, or delivered to the
                               Project Company with respect to the actual or
                               alleged noncompliance by the Project Company with
                               the terms of the Concession Agreement;

"GoM Lien"                     the lien granted by the Project Company to the
                               GoM pursuant to the Asset Purchase Agreement;

"IFC Disbursement"             an A Loan Disbursement or a B Loan Disbursement
                               or both, as the context requires;

"IFC Guarantee"                the Guarantee Agreement dated December 5, 2000
                               between the Project Company and IFC;

"IFC Loan"                     collectively, the A Loan and the B Loan or, as
                               the context requires, the principal amount of the
                               A Loan and the B Loan outstanding from time to
                               time;

"IFC Shares"                   the aggregate of:

                                     (A)   all shares in the share capital of
                                           the Borrower subscribed for and
                                           acquired by IFC pursuant to the
                                           Subscription Agreement;

                                     (B)   all shares of the Borrower to be
                                           subscribed or acquired by IFC after
                                           the execution of this agreement
                                           pursuant to the exercise of
                                           preemptive rights, options or
                                           warrants accruing to IFC in relation
                                           of any IFC Shares;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 7 -

                                     (C)   all shares of the Borrower received
                                           by IFC after the execution of this
                                           agreement as a result of stock splits
                                           or stock dividends on any IFC Shares;
                                           and

                                     (D)   all shares (of any company) received
                                           by IFC in exchange, replacement or
                                           substitution of the IFC Shares;

"IFC Subscription"             the subscription by IFC to shares of the Borrower
                               provided for in the Subscription Agreement;

"Increased Costs"              the amount certified in an Increased Costs
                               Certificate to be the net incremental costs of,
                               or reduction in return to, IFC or any Participant
                               in connection with the making or maintaining of
                               the IFC Loan or its Participation that result
                               from:

                               (i)   any change in any applicable law or
                                     regulation or directive (whether or not
                                     having force of law) or in its
                                     interpretation or application by any
                                     Authority charged with its administration;
                                     or

                               (ii)  compliance with any request from, or
                                     requirement of, any central bank or other
                                     monetary or other Authority;

                               which, in either case, after the date of this
                               Agreement:

                                     (A)   imposes, modifies or makes applicable
                                           any reserve, special deposit or
                                           similar requirements against assets
                                           held by, or deposits with or for the
                                           account of, or loans made by, IFC or
                                           that Participant;

                                     (B)   imposes a cost on IFC as a result of
                                           IFC having made the IFC Loan or on
                                           that Participant as a result of that
                                           Participant having acquired its
                                           Participation or reduces the rate of
                                           return on the overall capital of IFC
                                           or that Participant that it would
                                           have achieved, had IFC not made the
                                           IFC Loan or that Participant not
                                           acquired its Participation, as the
                                           case may be;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 8 -

                                     (C)   changes the basis of taxation on
                                           payments received by IFC in respect
                                           of the IFC Loan or by that
                                           Participant with respect to its
                                           Participation (otherwise than by a
                                           change in taxation of the overall net
                                           income of IFC or that Participant
                                           imposed by the jurisdiction of its
                                           incorporation or in which it books
                                           its Participation or in any political
                                           subdivision of any such
                                           jurisdiction); or

                                     (D)   imposes on IFC or that Participant
                                           any other condition regarding the
                                           making or maintaining of the IFC Loan
                                           or its Participation,

                               but excluding any incremental costs of making or
                               maintaining a Participation that are a direct
                               result of that Participant having its principal
                               office in Mexico or having or maintaining a
                               permanent office or establishment in Mexico, if
                               and to the extent that permanent office or
                               establishment acquires that Participation;

"Increased Costs Certificate"  a certificate provided from time to time by IFC
                               (based on a certificate to IFC from any
                               Participant, if the Increased Costs affect its
                               Participation), certifying:

                               (i)   the circumstances giving rise to the
                                     Increased Costs;

                               (ii)  that the costs of IFC or, as the case may
                                     be, that Participant, have increased or the
                                     rate of return of either of them has been
                                     reduced as a result of the Increased Costs;

                               (iii) that, IFC or, as the case may be, that
                                     Participant, has, in its opinion, exercised
                                     reasonable efforts to minimize or eliminate
                                     the relevant increase or reduction, as the
                                     case may be; and

                               (iv)  the amount of Increased Costs;

"Interest Determination
Date"                          except as otherwise provided in Section 3.03 (d)
                               (ii) (Interest) the second Business Day before
                               the beginning of each Interest Period;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 9 -

"Interest Payment Date"        March 15 and September 15 in any year or, in the
                               case of any Interest Period of less than six (6)
                               months, any day which is the 15th day of the
                               month in which the relevant Interest Period ends;

"Interest Period"              each period of six (6) months or, in the
                               circumstances referred to in Section 3.04 (Change
                               in Interest Period), each period of three (3)
                               months or one (1) month determined pursuant to
                               that Section, in each case beginning on an
                               Interest Payment Date and ending on the day
                               immediately before the next following Interest
                               Payment Date, except in the case of the first
                               period applicable to an IFC Disbursement when it
                               means the period beginning on the date on which
                               such IFC Disbursement is made and ending on the
                               day immediately before the next following
                               Interest Payment Date;

"Interest Rate"                (i) with respect to the A Loan, the A Loan
                               Interest Rate, or (ii) with respect to the B
                               Loan, the B Loan Interest Rate, as the context
                               requires;

"ITISA"                        Impulsora Tlaxcalteca de Industrias, S.A. de
                               C.V., a sociedad anonima de capital variable
                               organized and existing under the laws of Mexico;

"Letter of Information"        the Letter of Information, dated March 8, 2000,
                               provided to IFC by the Project Company with
                               respect to the Project, as amended by the Letter
                               of Information, dated November 14, 2000, provided
                               to the Senior Lenders by the Borrower;

"LIBOR"                        the British Bankers' Association ("BBA")
                               interbank offered rates for deposits in Dollars
                               which appear on the relevant page of the Telerate
                               Service (currently page 3750) or, if not
                               available, on the relevant pages of any other
                               service (such as Reuters Service or Bloomberg
                               Financial Markets Service) that displays such BBA
                               rates; provided that if BBA for any reason ceases
                               (whether permanently or temporarily) to publish
                               interbank offered rates for deposits in Dollars,
                               "LIBOR" shall mean the rate determined pursuant
                               to Section 3.03 (d) (Interest);

"Lien"                         any mortgage, pledge, charge, assignment,
                               hypothecation, security interest, title
                               retention, preferential right, trust arrangement,
                               right of set-off, counterclaim or banker's lien,
                               privilege or priority of any kind having the
                               effect of security, any designation of loss
                               payees or beneficiaries or

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 10 -

                               any similar arrangement under or with respect to
                               any insurance policy or any preference of one
                               creditor over another arising by operation of
                               law;

"Loans"                        collectively, the A Loan, the B Loan and the FMO
                               Loan or, as the context requires, the principal
                               amount of the A Loan, the B Loan and the FMO Loan
                               outstanding from time to time;

"Long-term Contract"           any contract between the Borrower and the Project
                               Company or between the Borrower and/or the
                               Project Company and any third party, in each case
                               with a term that is longer than one year and
                               generating proceeds to the Borrower and/or the
                               Project Company of at least $1,000,000 annually;

"Material Adverse Effect"

                               a material adverse effect on:

                               (i)   the Borrower or the Project Company, its
                                     assets or properties;

                               (ii)  the Borrower's or the Project Company's
                                     business prospects (as reflected in the
                                     Project Company's base case projections) or
                                     financial condition;

                               (iii) the implementation of the Project, the
                                     Financial Plan or the carrying on of the
                                     Borrower's or the Project Company's
                                     business or operations;

                               (iv)  the ability of the Borrower or the Project
                                     Company to comply with its obligations
                                     under this Agreement or any other
                                     Transaction Document or Project Document;
                                     or

                               (v)   the Sponsor, if any of the events specified
                                     in clauses (i) through (iv) above occurs
                                     with respect to the Sponsor;

"Mercantile Pledge
Agreements"                    collectively, the Mercantile Pledge Agreement,
                               dated as of December 5, 2000 by and among the
                               Sponsor, the Project Company, the Borrower and
                               the Senior Lenders; and the Mercantile Pledge
                               Agreement, dated as of December 5, 2000, by and
                               among the Borrower, the Sponsor and the Senior
                               Lenders;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 11 -

"Merger"                       the proposed merger of the Project Company with
                               and into the Borrower, with the Borrower as the
                               surviving entity;

"Merger Deadline Date"         the later of (i) January 1, 2010 and (ii) the
                               date that is six (6) months after the date of
                               filing of the Project Company's tax return that
                               demonstrates that the Project Company's net
                               operating losses for tax purposes have been fully
                               utilized;

"Merger Effective Date"        the date on which the Merger shall have been
                               consummated and all of the conditions precedent
                               to the Merger listed in Section 9.01 shall have
                               been fully satisfied or waived;

"Mexico"                       the United Mexican States;

"Note" or "Notes"              the promissory notes referred to in Article III,
                               or any of them;

"Official"                     any officer of a political party or candidate for
                               political office in Mexico or any officer or
                               employee (i) of the GoM (including any
                               legislative, judicial, executive or
                               administrative department, agency or
                               instrumentality thereof) or (ii) of a public
                               international organization;

"Participant"                  any Person who acquires a Participation;

"Participation"                the interest of any Participant in the B Loan, or
                               as the context requires, in a Disbursement of the
                               B Loan;

"Participation Agreement"      any of the agreements entitled "Participation
                               Agreement" between IFC and the Participants
                               pursuant to which each Participant acquires a
                               Participation;

"Person"                       any natural person, corporation, company,
                               partnership, firm, voluntary association, joint
                               venture, trust, unincorporated organization,
                               Authority or any other entity whether acting in
                               an individual, fiduciary or other capacity;

"Potential Event of Default"   any event or circumstance which would, with
                               notice, lapse of time, the making of a
                               determination or any combination thereof, become
                               an Event of Default;

"Prohibited Payments"          any offer, gift, payment, promise to pay or
                               authorization of the payment of any money or
                               anything of value, directly or indirectly, to or
                               for the use or benefit of any Official (including
                               to or for the use or benefit of any other Person
                               if

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 12 -

                               the Borrower, the Project Company or the Sponsor
                               knows, or has reasonable grounds for believing,
                               that the other Person would use such offer, gift,
                               payment, promise or authorization of payment for
                               the benefit of any such Official), for the
                               purpose of influencing any act or decision or
                               omission of any Official in order to obtain,
                               retain or direct business to, or to secure any
                               improper benefit or advantage for, the Borrower,
                               the Project Company, the Sponsor, their
                               respective Affiliates or any other Person;
                               provided that any such offer, gift, payment,
                               promise or authorization of payment shall not be
                               considered a Prohibited Payment if, in IFC's
                               reasonable opinion, it (i) is lawful under
                               applicable written laws and regulations or (ii)
                               is made for the purpose of expediting or securing
                               the performance of a routine governmental action
                               (as such term is construed under applicable law);

"Project"                      the project described in Section 2.01 (The
                               Project);

"Project Documents"            (i)   the Concession Agreement;

                               (ii)  the Asset Purchase Agreement;

                               (iii) the Technical Assistance Agreement;

                               (iv)  the Security Trust Indenture;

                               (v)   the Urgent Repairs Agreement; and

                               (vi)  the Credit Line Agreement;

"Put Option Agreement"         the agreement entitled "Put Option Agreement"
                               dated December 5, 2000, as amended as of the date
                               hereof, between the Sponsor, the Borrower and
                               IFC;

"Railroad Law"                 Mexico's Law Regulating Railroad Services (Ley
                               Reglamentaria del Servicio Ferroviario) and the
                               applicable rules and regulations thereunder, as
                               amended from time to time;

"Relevant Spread"              three and one-half per cent (3.5%) per annum;
                               provided, that the "Relevant Spread" shall equal
                               four per cent (4%) per annum for each Interest
                               Period beginning on or after (i) September 15,
                               2009, in the case of the A Loan and (ii)
                               September 15, 2008, in the case of the B Loan;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 13 -

"SCT"                          the Secretaria de Comunicaciones y Transportes of
                               Mexico;

"SCT Letter"                   a letter from SCT to the effect that the Project
                               Company shall be entitled to indemnification
                               pursuant to the applicable provisions of the
                               Railroad Law, including Section 23 thereof, in
                               the event of a unilateral modification of the
                               Concession Agreement;

"Security"                     the security created by or pursuant to the
                               Security Documents to secure all amounts owing by
                               the Borrower to IFC and FMO under the Transaction
                               Documents;

"Security Documents"           the documents providing for the Security
                               consisting of:

                               (i)   a first ranking pledge over all the present
                                     and future movable assets of the Project
                                     Company and the Borrower;

                               (ii)  a first ranking mortgage over all the
                                     present and future immovable assets of each
                                     of the Project Company and the Borrower, if
                                     any;

                               (iii) a first ranking pledge over all the present
                                     and future accounts receivable of each of
                                     the Project Company and the Borrower;

                               (iv)  a first ranking pledge over all of the
                                     Project Company's title to, rights and
                                     interest in the Project Documents other
                                     than the Urgent Repairs Agreement;

                               (v)   a first ranking pledge over all of the
                                     Project Company's or the Borrower's title
                                     to, rights and interest in all Long-term
                                     Contracts;

                               (vi)  a first ranking pledge over all of the
                                     Project Company's and the Borrower's title
                                     to, rights and interest in their respective
                                     present and future bank accounts;

                               (vii) a first ranking pledge over the Sponsor's
                                     shares in the Borrower;

                               (viii) a first ranking pledge over the Sponsor's
                                     and the Borrower's shares in the Project
                                     Company; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 14 -

                               (ix)  nomination of IFC as a loss
                                     payee/beneficiary in respect of the
                                     insurance obtained in connection with the
                                     assets subject to the Security Documents
                                     and a first ranking pledge over such
                                     insurance policies and proceeds;

                               provided, that for all purposes of the Security
                               Sharing Agreement dated December 5, 2000 between
                               FMO and IFC, the Sponsor Guarantee Agreement
                               shall also be considered a Security Document;

"Security Trust
Indenture"                     the Security Trust Indenture dated August 17,
                               1999 between the Project Company and the GoM;

"Senior Lenders"               collectively, IFC and FMO;

"Sponsor"                      Genesee & Wyoming, Inc., a corporation organized
                               and existing under the laws of the State of
                               Delaware, United States of America;

"Sponsor Guarantee
Agreement"                     the agreement entitled "Sponsor Guarantee
                               Agreement" dated as of the date hereof between
                               the Sponsor and the Senior Lenders;

"Subscription Agreement"       the agreement entitled "Subscription Agreement"
                               dated December 5, 2000 between the Borrower and
                               IFC;

"Subsidiary"                   with respect to any Person, any entity:

                               (i)   over 50% of whose capital is owned,
                                     directly or indirectly, by that Person;

                               (ii)  for which that Person may nominate or
                                     appoint a majority of the members of the
                                     board of directors or such other body
                                     performing similar functions; or

                               (iii) which is otherwise effectively controlled
                                     by that Person;

"Taxes"                        any present or future taxes, withholding
                               obligations, duties and other charges of whatever
                               nature levied by any Authority;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 15 -

"Technical Assistance
Agreement"                     the Assistance Agreement dated June 16, 1999
                               between the Project Company and the Sponsor, as
                               amended by the Amended and Restated Assistance
                               Agreement dated December 6, 2000, between the
                               Project Company and the Sponsor;

"Transaction Documents"        (i)   this Agreement;

                               (ii)  the FMO Loan Agreement;

                               (iii) the Financial Support Agreement;

                               (iv)  the Security Documents;

                               (v)   the Subscription Agreement;

                               (vi)  the Put Option Agreement;

                               (vii) the Sponsor Guarantee Agreement;

                               (viii) the IFC Guarantee;

                               (ix)  the FMO Guarantee;

                               (x)   the Concession Termination Compensation
                                     Assignment Notice; and

                               (xi)  the Notes;

"Urgent Repairs
Agreement"                     the Set Price and Fixed Term Construction
                               Agreement dated February 18, 2000 between the
                               Project Company and ITISA;

"World Bank"                   the International Bank for Reconstruction and
                               Development, an international organization
                               established by Articles of Agreement among its
                               member countries; and

"Year 2000 Compliant"          with respect to a Person, that such Person's
                               software, hardware, firmware, automated process
                               control devices, electronic data transmission and
                               reception systems, or information systems will,
                               prior to, during and after, the calendar year
                               2000, operate and handle, without error, date
                               input and output information and, in particular,
                               will respond to two-digit year input and process
                               two-digit year

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 16 -

                               date information in ways that resolve the
                               ambiguity as to century in a disclosed, defined
                               and predetermined manner.

      Section 1.02. Financial Definitions. (a) Wherever used in this Agreement,
unless the context otherwise requires, the following terms have the meanings
opposite them:

"Consolidated" or
"Consolidated Basis"           (with respect to any financial statements to be
                               provided, or any financial calculation (including
                               financial ratios) to be made, under or for the
                               purposes of this Agreement and any other
                               Transaction Document) the method referred to in
                               Section 1.03 (d) (Financial Calculations);

"Current Assets"               the aggregate of the Person's cash, marketable
                               securities, trade and other receivables
                               realizable within one year, prepaid expenses
                               which are to be charged to income within one year
                               and inventories, but excluding funds temporarily
                               on hand pending application to property and
                               equipment included in the Project;

"Current Liabilities"          the aggregate of all liabilities of the Person
                               falling due on demand or within one year
                               (including the portion of Long-term Debt falling
                               due within one year), but excluding liabilities
                               for property, plant and equipment to the extent
                               that the amount of funds therefrom are excluded
                               from the calculation of Current Assets;

"Current Ratio"                the result obtained by dividing Current Assets by
                               Current Liabilities;

"Debt"                         the aggregate of all obligations (whether actual
                               or contingent) of the Person to pay or repay
                               money including, without limitation:

                               (i)   all Indebtedness for Borrowed Money;

                               (ii)  the aggregate amount then outstanding of
                                     all liabilities of any party to the extent
                                     the Person guarantees them or otherwise
                                     directly or indirectly obligates itself to
                                     pay them;

                               (iii) all liabilities of the Person (actual or
                                     contingent) under any conditional sale or a
                                     transfer with recourse or obligation to
                                     repurchase, including,

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 17 -

                                     without limitation, by way of discount or
                                     factoring of book debts or receivables; and

                               (iv)  all liabilities of the Person (actual or
                                     contingent) under its Charter, any
                                     resolution of its shareholders, or any
                                     agreement or other document binding on the
                                     Person to redeem any of its shares;

"Debt Service
Coverage Ratio"                the ratio obtained by dividing:

                               (i)   the aggregate, for the four (4) financial
                                     quarter period most recently ended prior to
                                     the relevant date of calculation for which
                                     audited Consolidated financial statements
                                     of the Person are available, of (A) net
                                     income after deduction of taxes payable on
                                     that net income (whether or not actually
                                     paid), (B) Non-Cash Items and (C) the
                                     amount of all payments that were due during
                                     such four (4) financial quarter period
                                     (whether or not actually paid) on account
                                     of interest and other charges on Debt; less
                                     amounts actually paid during such period in
                                     respect of any capital expenditure, other
                                     than capital expenditures required for
                                     carrying out the Project as described in
                                     Section 2.02(a) or essential to the Project
                                     Company's business and operations;

                                     by

                               (ii)  the aggregate of (A) all scheduled payments
                                     that fall due during the four (4) financial
                                     quarter period beginning with the financial
                                     quarter in which the relevant date of
                                     calculation falls (whether or not actually
                                     paid) on account of principal of Long-term
                                     Debt, and interest and other charges on
                                     Debt and (B) without double counting with
                                     respect to any payment already counted in
                                     the preceding sub-paragraph (A), any
                                     payment made or required to be made to any
                                     debt service account during such four (4)
                                     quarter period under the terms of any
                                     agreement providing for the Debt;

"EBITDA"                       the earnings of the Person before interest,
                               taxes, depreciation and amortization,
                               extraordinary increases or losses, gain or loss
                               on discontinued operations, and currency gains or
                               losses;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 18 -

"Free Cash Flow"               in respect of any financial year of any Person
                               and as reflected in such Person's financial
                               statements for such financial year:

                               (i)   the sum of such Person's (A) net income
                                     plus (B) Non-Cash Items (excluding accrued
                                     but unpaid interest on the FMO Loan and the
                                     IFC Loan);

                               minus

                               (ii)  the sum of (A) capital expenditures made by
                                     such Person plus (B) repayments on the
                                     principal component of Debt made by such
                                     Person;

"Indebtedness for
Borrowed Money"                all obligations of the Person to repay money
                               including, without limitation, with respect to:

                               (i)   borrowed money;

                               (ii)  the outstanding principal amount of any
                                     bonds, debentures, notes, loan stock,
                                     commercial paper, acceptance credits, bills
                                     or promissory notes drawn, accepted,
                                     endorsed or issued by the Person;

                               (iii) any credit to the Person from a supplier of
                                     goods or services under any installment
                                     purchase or other similar arrangement with
                                     respect to goods or services (except trade
                                     accounts that are payable in the ordinary
                                     course of business and included in Current
                                     Liabilities);

                               (iv)  non-contingent obligations of the Person to
                                     reimburse any other Person with respect to
                                     amounts paid by that Person under a letter
                                     of credit or similar instrument (excluding
                                     any letter of credit or similar instrument
                                     issued for the benefit of the Person with
                                     respect to trade accounts that are payable
                                     in the ordinary course of business and
                                     included in Current Liabilities);

                               (v)   amounts raised under any other transaction
                                     having the financial effect of a borrowing
                                     and which would be classified as a
                                     borrowing (and not as an off-balance sheet
                                     financing) under the Accounting

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 19 -

                                     Principles including, without limitation,
                                     under leases or similar arrangements
                                     entered into primarily as a means of
                                     financing the acquisition of the asset
                                     leased;

                               (vi)  the amount of the Person's obligations
                                     pursuant to Derivative Transactions which
                                     consist of swap, collar and cap agreements
                                     entered into in connection with other Debt
                                     of the Person, provided that for the
                                     avoidance of double counting and for so
                                     long as any such swap, collar or cap
                                     agreement is in effect, that Debt will be
                                     included in Indebtedness for Borrowed Money
                                     pursuant to the terms of the relevant
                                     Derivative Transaction and not the terms of
                                     the agreement providing for that Debt when
                                     it was incurred; and

                               (vii) any premium payable on a mandatory
                                     redemption or replacement of any of the
                                     foregoing obligations;

"Long-term Debt"               that part of the Debt the final maturity of
                               which, by its terms or the terms of any agreement
                               relating to it, falls due more than one year
                               after the date of its incurrence;

"Long-term Debt to
Tangible Net Worth Ratio"      the result obtained by dividing Long-term Debt
                               by Tangible Net Worth;

"Non-Cash Items"               for any period, the net aggregate amount (which
                               may be a positive or negative number) of all
                               non-cash expenses and non-cash credits which have
                               been subtracted or, as the case may be, added in
                               calculating net income during that period,
                               including, without limitation, depreciation,
                               amortization, deferred taxes, provisions for
                               severance pay of staff and workers, and credits
                               resulting from revaluation of the assets' book
                               value;

"Short-term Debt"              all Debt other than Long-term Debt.

"Tangible Net Worth"           on any date means (i) the sum of the Person's
                               total assets, minus (ii) the sum of:

                               (A)   the Person's total liabilities, plus

                               (B)   (to the extent not already included in the
                                     Person's total liabilities) an amount equal
                                     to the sum of the

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 20 -

                                     maximum liability of the Person under any
                                     guarantee or other obligation for the
                                     financial or other obligation of any third
                                     party, the amount of any taxes and any
                                     other commitments which, in each case in
                                     accordance with the Accounting Principles,
                                     should be recorded in the notes of the
                                     financial statements as a liability, plus

                               (C)   intangible assets of the Person (for
                                     purposes of this Agreement, the Concession
                                     Agreement (having a value of $7.5 million)
                                     shall be considered a tangible asset), plus

                               (D)   (to the extent not already included in the
                                     Person's total liabilities) any obligations
                                     of the Person under any capital lease
                                     (including any lease which should be
                                     capitalized in accordance with the
                                     Accounting Principles and any other lease
                                     which is in substance a financial lease).

      Section 1.03. Financial Calculations. (a) All financial calculations to be
made under, or for the purposes of, this Agreement and any other Transaction
Document shall be determined in accordance with the Accounting Principles and,
except as otherwise required to conform to any provisions of this Agreement,
shall be calculated from the then most recently issued Consolidated quarterly
financial statements which the Borrower is obligated to furnish to IFC under
Section 6.04 (a) (Reporting Requirements). Except as otherwise indicated, all
financial calculations with respect to the definitions in Section 1.02 shall be
done on a Consolidated Basis.

      (b) Where quarterly financial statements are used for the purpose of
making certain financial calculations and those statements are with respect to
the last quarter of a Financial Year then, at IFC's option, those calculations
may instead be made from the Consolidated audited financial statements for the
relevant Financial Year.

      (c) For purposes of the payment of dividends, the payment of subordinated
debt and the payment of technical assistance fees under the Technical Assistance
Agreement, if any material adverse change in the financial condition of the
Borrower has occurred after the end of the period covered by the financial
statements used to make the relevant financial calculations, that material
adverse change shall also be taken into account in calculating the relevant
figures.

      (d) If a financial calculation is to be made under or for the purposes of
this Agreement or any other Transaction Document on a Consolidated Basis, that
calculation shall be made by reference to the sum of all amounts of similar
nature reported in the relevant financial statements of each of the entities
whose accounts are to be consolidated with the accounts of the Borrower plus or
minus the consolidation adjustments

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 21 -

customarily applied to avoid double counting of transactions among any of those
entities, including the Borrower.

      Section 1.04. Interpretation. In this Agreement, unless the context
otherwise requires:

      (a) headings are for convenience only and do not affect the interpretation
of this Agreement;

      (b) words importing the singular include the plural and vice versa;

      (c) a reference to an Annex, Article, party, Schedule or Section is a
reference to that Article or Section of, or that Annex, party or Schedule to,
this Agreement;

      (d) a reference to a document includes an amendment or supplement to, or
replacement or novation of, that document but disregarding any amendment,
supplement, replacement or novation made in breach of this Agreement; and

      (e) a reference to a party to any document includes that party's
successors and permitted assigns.

      Section 1.05. Business Day Adjustment When the day on or by which a
payment is due to be made is not a Business Day, that payment shall be made on
or by the next succeeding Business Day. Interest, fees and charges (if any)
shall continue to accrue for the period from the due date that is not a Business
Day to that next succeeding Business Day.

                                   ARTICLE II

                  THE PROJECT, PROJECT COST AND FINANCIAL PLAN

      Section 2.01. The Project. The project to be financed consists of the
rehabilitation, modernization, and operation of the Chiapas and Mayab lines by
the Project Company pursuant to the Concession Agreement in the States of Oaxaca
and Chiapas (for the Chiapas line) and Campeche, Yucatan, Veracruz and Tabasco
(for the Mayab line), including repayment of all amounts outstanding under a
certain loan from Fleet National Bank, N.A., as further described in the Letter
of Information.

      Section 2.02. Project Cost and Financial Plan.(1) (a) The total estimated
cost of the Project is the equivalent of $49,150,000, as follows:

---------------
(1)   For purposes of this Section, an exchange rate of 9.4 Mexican Pesos = $1
      has been assumed.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 22 -

<TABLE>
<CAPTION>
                                               $ million
                                               equivalent               %
                                               ----------             -----
<S>                                            <C>                    <C>
Concession investment                              7.5                 15.0
Rolling Stock                                     12.3                 25.0
Urgent repair works                                9.7                 20.0
Intermodal                                         1.4                  3.0
Track rehabilitation                               4.9                 10.0
Locomotive repair                                  1.7                  3.5
Locomotive purchase                                2.2                  4.5
Other                                              1.0                  2.0
                                                 -----                -----
          SUB-TOTAL                               40.7                 83.0
                                                 -----                -----

Contingency                                        1.0                  2.0
Pre-opening expenses                              1.35                  3.0
Working capital                                    6.1                 12.0
                                                 -----                -----
          SUB-TOTAL                               8.45                 17.0
                                                 -----                -----

TOTAL PROJECT COST                               49.15                100.0
</TABLE>

(b)   The proposed sources of financing for the Project are as follows:

<TABLE>
<CAPTION>
                                              $ million
                                              equivalent         %
                                              ----------        ----
<S>                                           <C>               <C>
         Equity

Sponsor                                         13.10           26.7
IFC                                              1.90            3.9
                                                -----           ----
      TOTAL EQUITY                              15.00           30.5
                                                -----           ----

Long-term Debt

IFC "A" Loan                                    10.50           21.4
IFC "B" Loan                                    10.00           20.4
FMO Loan                                         7.00           14.2
                                                -----           ----
      TOTAL LONG-TERM DEBT                      27.50           56.0
                                                -----           ----

Cash generation                                  6.65           13.5

TOTAL FINANCING                                 49.15            100
                                                =====           ====
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 23 -

                                   ARTICLE III

                                    THE LOAN

      Section 3.01. The Loan. Subject to the provisions of this Agreement, IFC
agrees to lend, and the Borrower agrees to borrow, the IFC Loan consisting of:

      (a) the A Loan, being ten million five hundred thousand Dollars
($10,500,000); and

      (b) the B Loan, being ten million Dollars ($10,000,000).

      Section 3.02. [reserved].

      Section 3.03. Interest. Subject to the provisions of Section 3.05 (Default
Rate Interest), the Borrower shall pay interest on the IFC Loan in accordance
with this Section 3.03:

      (a) During each Interest Period, the IFC Loan (or, with respect to the
first Interest Period for the IFC Disbursement, the amount of the Disbursement)
shall bear interest at the applicable Interest Rate for that Interest Period.

      (b) Interest on each of the A Loan and the B Loan shall accrue from day to
day, be prorated on the basis of a 360-day year for the actual number of days in
the relevant Interest Period and be payable in arrears on the Interest Payment
Date immediately following the end of that Interest Period; provided that if the
IFC Disbursement is made less than fifteen (15) days before an Interest Payment
Date, interest on the IFC Disbursement shall be payable commencing on the second
Interest Payment Date following the date of the IFC Disbursement.

      (c) Subject to Section 3.04 (Change in Interest Period), the A Loan
Interest Rate and the B Loan Interest Rate for any Interest Period shall be the
rate which is the sum of:

            (i)   the Relevant Spread; and

            (ii)  LIBOR on the Interest Determination Date for that Interest
                  Period for six (6) months (or, in the case of the first
                  Interest Period for any Disbursement, for one (1) month, two
                  (2) months, three (3) months or six (6) months, whichever
                  period is closest to the duration of the relevant Interest
                  Period (or, if two periods are equally close, the longer one))
                  rounded upward to the nearest three decimal places.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 24 -

      (d) If, for any Interest Period, IFC cannot determine LIBOR by reference
to the Telerate Service or any other service that displays BBA rates, IFC shall
notify the Borrower and shall instead determine LIBOR:

            (i)   on the second Business Day before the beginning of the
                  relevant Interest Period by calculating the arithmetic mean
                  (rounded upward to the nearest three decimal places) of the
                  offered rates advised to IFC on or around 11:00 a.m., London
                  time, for deposits in Dollars and otherwise in accordance with
                  Section 3.03 (c) (ii), by any four (4) major banks active in
                  Dollars in the London interbank market, selected by IFC;
                  provided that if less than four quotations are received, IFC
                  may rely on the quotations so received if not less than two
                  (2); or

            (ii)  if less than two (2) quotations are received from the banks in
                  London in accordance with subsection (i) above, on the first
                  day of the relevant Interest Period, by calculating the
                  arithmetic mean (rounded upward to the nearest three decimal
                  places) of the offered rates advised to IFC on or around 11:00
                  a.m., New York time, for loans in Dollars and otherwise in
                  accordance with Section 3.03 (c) (ii), by a major bank or
                  banks in New York, New York selected by IFC.

      (e) On each Interest Determination Date for any Interest Period, IFC shall
determine the A Loan Interest Rate and the B Loan Interest Rate applicable to
that Interest Period and promptly notify the Borrower of those rates.

      (f) The determination by IFC, from time to time, of the applicable
Interest Rate shall be final and conclusive and bind the Borrower (unless the
Borrower shows to IFC's satisfaction that the determination involves manifest
error).

      Section 3.04. Change in Interest Period. Without prejudice to the
provisions of Section 3.05 (Default Rate Interest), if at any time the Borrower
fails to pay any amount of principal of, or interest on, the IFC Loan when due
(whether at stated maturity or upon acceleration), and any part of that amount
remains unpaid on the third Business Day immediately preceding any Interest
Payment Date falling after that amount became due, then:

      (a) IFC may elect that the duration of the Interest Period commencing on
that Interest Payment Date and, subject to Section 3.04 (c), any subsequent
Interest Period shall be either three (3) months or one (1) month and shall
notify the Borrower of that election in the notice referred to in Section 3.03
(e) (Interest);

      (b) the Interest Rates applicable to any Interest Period which is three
(3) months or one (1) month shall be determined in accordance with Section 3.03
(Interest)

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 25 -

in all respects, except that any reference in Section 3.03 (c) (ii) to six (6)
months shall be deemed to be a reference to three (3) months or, as the case may
be, one (1) month; and

      (c) unless an Event of Default or Potential Event of Default has occurred
and is continuing, IFC shall reinstate Interest Periods of six (6) months as of
the first Interest Payment Date which is March 15 or September 15 falling at
least three (3) Business Days after the payment default is remedied in full and
shall inform the Borrower of that reinstatement in the notice referred to in
Section 3.03 (e) (Interest).

      Section 3.05. Default Rate Interest. (a) Without limiting the remedies
available to IFC under this Agreement or otherwise (and to the maximum extent
permitted by applicable law), if the Borrower fails to make any payment of
principal or interest (including interest payable pursuant to this Section) or
any other payment provided for in Section 3.08 (Fees) when due as specified in
this Agreement (whether at stated maturity or upon acceleration), the Borrower
shall pay interest on the amount of that payment due and unpaid at the default
rate which shall be the sum of two per cent (2%) per annum and the A Loan
Interest Rate (with respect to amounts relating to the A Loan) or two per cent
(2%) per annum and the B Loan Interest Rate (with respect to amounts relating to
the B Loan) in effect from time to time;

      (b) Interest at the rate referred to in Section 3.05 (a) shall accrue from
the date on which payment of the relevant overdue amount became due until the
date of actual payment of that amount (as well after as before judgment), and
shall be payable on demand or, if not demanded, on each Interest Payment Date
falling after any such overdue amount became due.

      Section 3.06. Repayment. (a) The Borrower shall repay the A Loan on the
following dates and in the following amounts:

<TABLE>
<CAPTION>
Date Payment Due                         Principal Amount Due
------------------                       --------------------
<S>                                      <C>
March 15, 2005                               $    455,000
September 15, 2005                           $    455,000
March 15, 2006                               $    455,000
September 15, 2006                           $    455,000
March 15, 2007                               $    455,000
September 15, 2007                           $    455,000
March 15, 2008                               $    455,000
September 15, 2008                           $    455,000
March 15, 2009                               $    455,000
September 15, 2009                           $    455,000
March 15, 2010                               $    455,000
September 15, 2010                           $    455,000
March 15, 2011                               $    455,000
September 15, 2011                           $    455,000
March 15, 2012                               $    455,000
</TABLE>

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 26 -

<TABLE>
<S>                                          <C>
September 15, 2012                           $    455,836
                                             ------------

          TOTAL                              $  7,280,836
                                             ============
</TABLE>

      (b) The Borrower shall repay the B Loan on the following dates and in the
following amounts:

<TABLE>
<CAPTION>
Date Payment Due                         Principal Amount Due
------------------                       --------------------
<S>                                      <C>
March 15, 2005                               $    461,250
September 15, 2005                           $    461,250
March 15, 2006                               $    461,250
September 15, 2006                           $    461,250
March 15, 2007                               $    461,250
September 15, 2007                           $    461,250
March 15, 2008                               $    461,250
September 15, 2008                           $    461,250
March 15, 2009                               $    461,250
September 15, 2009                           $    461,250
March 15, 2010                               $    461,250
September 15, 2010                           $    461,250
March 15, 2011                               $    461,250
September 15, 2011                           $    461,691
                                             ------------

          TOTAL                              $  6,457,941
                                             ============
</TABLE>

      (c) The dates for repayment of principal of the IFC Loan are intended to
coincide with the original Interest Payment Dates.

      Section 3.07. Prepayment. Subject to Section 3.14, Section 3.16 and
Section 6.05 (c):

      (a) the Borrower may prepay on any Interest Payment Date all or any part
of the IFC Loan, on not less than thirty (30) days' prior notice to IFC, but
only if:

            (i)   the Borrower simultaneously pays all accrued interest and
                  Increased Costs (if any) on the amount of the IFC Loan to be
                  prepaid, together with all other amounts then due and payable
                  under this Agreement, including the amount payable under
                  Section 3.12 (Unwinding Costs), if the prepayment is not made
                  on an Interest Payment Date;

            (ii)  the Borrower simultaneously prepays a pro rata portion of the
                  FMO Loan;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 27 -

            (iii) (reserved); and

            (iv)  if requested by IFC, the Borrower delivers to IFC, prior to
                  the date of prepayment, evidence satisfactory to IFC that all
                  necessary Authorizations with respect to the prepayment of the
                  IFC Loan and FMO Loan have been obtained.

      (b) Not later than the first Interest Payment Date following the
Borrower's delivery of annual financial statements (as required under Section
6.04 (Reporting Requirements)) after the end of each Financial Year of the
Borrower ending on or after December 31, 2005, the Borrower shall make mandatory
prepayments of the FMO Loan and the IFC Loan in an aggregate amount equal to the
Borrower's Consolidated Free Cash Flow for such Financial Year minus one million
Dollars ($1,000,000). Such aggregate amount shall be allocated between the FMO
Loan and the IFC Loan in proportion to the respective principal amounts
outstanding of each Loan. At least ten (10) Business Days prior to any
prepayment required under this Section 3.07(b), the Borrower shall deliver a
notice to IFC, certified by its Chief Financial Officer, specifying the amount
of the prepayment required under this Section 3.07(b). Other than Section
3.07(a)(ii), the terms of this Section 3.07 shall apply to any prepayment made
under this Section 3.07(b).

      (c) Amounts of principal prepaid under this Section shall:

            (i)   first be allocated by IFC pro rata between the A Loan and the
                  B Loan in proportion to their respective principal amounts
                  outstanding; and

            (ii)  then be applied by IFC to the respective outstanding
                  installments of principal of the A Loan and the B Loan in
                  inverse order of maturity.

      (d) Upon delivery of a notice in accordance with Section 3.07 (a) or (b),
the Borrower shall make the prepayment in accordance with the terms of that
notice.

      (e) Any principal amount of the IFC Loan prepaid under this Agreement may
not be re-borrowed.

      Section 3.08. Fees. (a) The Borrower shall pay to IFC a commitment fee at
the rate of one-half of one per cent (1/2%) per annum on that part of the IFC
Loan which from time to time has not been disbursed or cancelled. The commitment
fee shall:

            (i)   begin to accrue,

                  (A)   with respect to the A Loan, on the date of this
                        Agreement; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 28 -

                  (B)   with respect to the B Loan, for each Participation, on
                        the date of the Participation Agreement evidencing that
                        Participation;

            (ii)  be pro rated on the basis of a 360-day year for the actual
                  number of days elapsed; and

            (iii) be payable semi-annually, in arrears, on the Interest Payment
                  Dates in each year, the first such payment to be due on March
                  15, 2001.

      (b)   The Borrower shall also pay to IFC:

            (i)   a front-end fee on the A Loan of one hundred five thousand
                  Dollars ($105,000), to be paid upon the earlier of (x) the
                  date which is thirty (30) days after the date of this
                  Agreement and (y) the date immediately preceding the date of
                  the first A Loan Disbursement;

            (ii)  a front-end fee on the B Loan of one hundred thousand Dollars
                  ($100,000), to be paid, upon the earlier of (x) the date which
                  is thirty (30) days after the date of the relevant
                  Participation Agreement and (y) the date immediately preceding
                  the first B Loan Disbursement from the relevant Participation;

            (iii) a syndication fee of one hundred seventy thousand Dollars
                  ($170,000), to be paid, upon the earlier of (x) the date which
                  is thirty (30) days after the date of the relevant
                  Participation Agreement and the FMO Loan Agreement and (y) the
                  date immediately preceding the first B Loan Disbursement from
                  the relevant Participation and the FMO Disbursement;

            (iv)  an annual B Loan administration fee of five thousand Dollars
                  ($5,000) per Participant for each calendar year during which
                  any portion of that Participant's Participation is committed
                  or outstanding, whether that year is complete or not, to be
                  paid in full in advance:

                  (A)   with respect to the first calendar year, within thirty
                        (30) days after the date of the relevant Participation
                        Agreement; and

                  (B)   with respect to each subsequent calendar year, on the
                        first Interest Payment Date in that year;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 29 -

            (v)   a success fee of two hundred seventy-five thousand Dollars
                  ($275,000), to be paid in full in advance on the date of
                  signing of the Participation Agreement and the FMO Loan
                  Agreement; and

            (vi)  such other fees as agreed to by IFC and the Borrower in
                  connection with the amendment and restatement of the Original
                  IFC Loan Agreement and the other transactions contemplated
                  hereby, to be paid prior to the effectiveness of this
                  Agreement.

      Section 3.09. Currency and Place of Payments. (a) The Borrower shall make
all payments of principal, interest, fees, and any other amount due to IFC under
this Agreement in Dollars, in same day funds, to the account of IFC at Northern
Trust International Banking Corporation, New York, New York, U.S.A., CHIP UID
142255, or at such other bank or account in New York as IFC from time to time
designates. Payments must be received in IFC's designated account no later than
1:00 p.m. New York time; and the Borrower hereby irrevocably agrees that IFC may
deem any payment, or part thereof, relating to the B Loan that is received after
that time as made on the next Business Day and accordingly interest will accrue
on any Participant's pro rata share of that payment with respect to which IFC is
unable to make same day remittance to that Participant.

      (b) The tender or payment of any amount payable under this Agreement
(whether or not by recovery under a judgment) in any currency other than Dollars
shall not novate, discharge or satisfy the obligation of the Borrower to pay in
Dollars all amounts payable under this Agreement except to the extent that (and
as of the date when) IFC actually receives funds in Dollars in the account
specified in, or pursuant to, Section 3.09 (a).

      (c) The Borrower shall indemnify IFC against any losses resulting from a
payment being received or an order or judgment being given under this Agreement
in any currency other than Dollars or in any place other than the account
specified in, or pursuant to, Section 3.09 (a). The Borrower shall, as a
separate obligation, pay such additional amount as is necessary to enable IFC to
receive, after conversion to Dollars at a market rate and transfer to that
account, the full amount due to IFC under this Agreement in Dollars and in the
account specified in, or pursuant to, Section 3.09 (a).

      (d) Notwithstanding the provisions of Section 3.09 (a) and Section 3.09
(b), IFC may require the Borrower to pay (or reimburse IFC) for any Taxes, fees,
costs, expenses and other amounts payable under Section 3.14 (a) (Taxes) and
Section 3.15 (Expenses) in the currency in which they are payable, if other than
Dollars.

      Section 3.10. Allocation of Partial Payments. If at any time IFC receives
less than the full amount then due and payable to it under this Agreement, IFC
may allocate and apply the amount received in any way or manner and for such
purpose or purposes under this Agreement as IFC in its sole discretion
determines, notwithstanding any instruction that the Borrower may give to the
contrary.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 30 -

      Section 3.11. Increased Costs. On each Interest Payment Date, the Borrower
shall pay, in addition to interest, the amount which IFC from time to time
notifies to the Borrower in an Increased Costs Certificate as being the
aggregate Increased Costs of IFC and each Participant accrued and unpaid prior
to that Interest Payment Date.

      Section 3.12. Unwinding Costs. (a) If IFC or any Participant incurs any
cost, expense or loss as a result of the Borrower

            (i)   failing to borrow in accordance with a request for
                  Disbursement made pursuant to Section 3.02 (Disbursement
                  Procedure), or to prepay in accordance with a notice of
                  prepayment; or

            (ii)  prepaying all or any portion of the IFC Loan on a date other
                  than an Interest Payment Date;

then the Borrower shall immediately pay to IFC the amount which IFC from time to
time notifies to the Borrower as being the amount of those costs, expenses and
losses incurred.

      (b) For the purposes of this Section, "costs, expenses or losses" include
any premium, penalty or expense incurred to liquidate or obtain third party
deposits or borrowings in order to make, maintain or fund all or any part of the
IFC Loan.

      Section 3.13. [reserved]

      Section 3.14. Taxes. (a) The Borrower shall pay or cause to be paid all
Taxes, other than taxes, if any, payable on the overall income of IFC, on or in
connection with the payment of any and all amounts due under this Agreement that
are now or in the future levied or imposed by any Authority of Mexico or any
jurisdiction through or out of which a payment is made.

      (b) All payments of principal, interest, fees and other amounts due under
this Agreement shall be made without deduction for or on account of any Taxes.

      (c) If the Borrower is prevented by operation of law or otherwise from
making or causing to be made those payments without deduction, the principal or
(as the case may be) interest, fees or other amounts due under this Agreement
shall be increased to such amount as may be necessary so that IFC receives the
full amount it would have received (taking into account any Taxes payable on
amounts payable by the Borrower under this subsection) had those payments been
made without that deduction.

      (d) If Section 3.14 (c) applies and IFC so requests, the Borrower shall
deliver to IFC official tax receipts evidencing payment (or certified copies of
them) within thirty (30) days of the date of that request.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 31 -

      (e) Section 3.14 (a) and Section 3.14 (b) do not apply to Taxes which
directly result from a Participant (or, as the case may be, a participant with a
comparable participation in the A Loan) having its principal office in Mexico or
having or maintaining a permanent office or establishment in Mexico, if and to
the extent that such permanent office or establishment acquires the relevant
Participation (or a comparable participation in the A Loan).

      Section 3.15. Expenses. (a) The Borrower shall pay or, as the case may be,
reimburse IFC or its assignees any amount paid by them on account of, all taxes
(including stamp taxes), duties, fees or other charges payable on or in
connection with the execution, issue, delivery, registration or notarization of
the Transaction Documents and any other documents related to this Agreement or
any other Transaction Document.

      (b)   The Borrower shall pay to IFC or as IFC may direct:

            (i)   the reasonable out-of-pocket travel expenses of IFC relating
                  to the supervision of the CAP;

            (ii)  the fees and expenses of IFC's counsel in Mexico and New York
                  incurred in connection with:

                  (A)   the preparation of the investment by IFC provided for
                        under this Agreement and any other Transaction Document;

                  (B)   the preparation and/or review, execution and, where
                        appropriate, translation and registration of the
                        Transaction Documents and any other documents related to
                        them;

                  (C)   the giving of any legal opinions required by IFC under
                        this Agreement and any other Transaction Document;

                  (D)   the administration by IFC of the investment provided for
                        in this Agreement or otherwise in connection with any
                        amendment, supplement or modification to, or waiver
                        under, any of the Transaction Documents;

                  (E)   the registration (where appropriate) and the delivery of
                        the evidences of indebtedness relating to the IFC Loan
                        and its disbursement;

                  (F)   matters pertaining to the IFC Subscription;

                  (G)   the occurrence of any Event of Default or Potential
                        Event of Default; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 32 -

                  (H)   for the avoidance of doubt, the preparation of the
                        amendment and restatement of the Original IFC Loan
                        Agreement contemplated by this Agreement, the
                        preparation of the other Transaction Documents listed in
                        Section 5.01(a) (Conditions of Effectiveness) and the
                        giving of any legal opinions in connection herewith and
                        therewith;

            (iii) in the year 2000 and in each calendar year thereafter upon
                  receipt of a statement from IFC, the amount of up to ten
                  thousand Dollars ($10,000) on account of IFC's expenses in
                  carrying out its annual supervision review of the Borrower,
                  the Project Company and the Project; and

            (iv)  the costs and expenses incurred by IFC in relation to efforts
                  to enforce or protect its rights under any Transaction
                  Document, or the exercise of its rights or powers consequent
                  upon or arising out of the occurrence of any Event of Default
                  or Potential Event of Default, including legal and other
                  professional consultants' fees.

      Section 3.16. Illegality of Participation. If, after the date of this
Agreement, any change made in any applicable law or regulation or official
directive (or its interpretation or application by any Authority charged with
its administration) (herein the "Relevant Change") makes it unlawful for any
Participant to continue to maintain or to fund its Participation:

      (a) the Borrower shall, upon request by IFC (but subject to any applicable
Authorization having been obtained), on the earlier of (i) the next Interest
Payment Date and (ii) the date that IFC advises the Borrower is the latest day
permitted by the Relevant Change, prepay in full that part of the B Loan that
IFC advises corresponds to that Participation;

      (b) concurrently with the prepayment of the part of the B Loan
corresponding to the Participation affected by the Relevant Change, the Borrower
shall pay all accrued interest, Increased Costs (if any) on that part of the B
Loan (and, if that prepayment is not made on an Interest Payment Date, any
amount payable in respect of the prepayment under Section 3.12 (Unwinding
Costs));

      (c) the Borrower agrees to take all reasonable steps to obtain, as quickly
as possible after receipt of IFC's request for prepayment, the Authorization
referred to in Section 3.16 (a) if any such Authorization is then required; and

      (d) the Borrower shall have no further right to disbursement of the
undisbursed portion of the B Loan corresponding to that Participation after it
has received IFC's request for prepayment under this Section.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 33 -

      Section 3.17. Notes. (a) The Borrower shall issue non-negotiable Notes to
IFC in the form of Schedule 11 and otherwise in form and substance satisfactory
to IFC in connection with and at the time of each Disbursement.

      (b) The issuance of Notes pursuant to this Agreement shall not entail a
novation with respect to this Agreement or the IFC Loan. Notwithstanding the
foregoing, payment of the principal of any Note shall pro tanto discharge the
obligation of the Borrower to repay the portion of the IFC Loan to which such
Note relates; and the payment of interest on the Note shall pro tanto discharge
the obligation of the Borrower to pay interest on that portion of the IFC Loan
to which such Note relates.

      (c) The Borrower represents that, after the delivery thereof, each Note
shall constitute in Mexico a valid binding and enforceable obligation of the
Borrower in accordance with its terms and, if IFC so requests, the Borrower
shall furnish IFC evidence satisfactory to IFC that all formalities required for
that purpose have been satisfied.

                                   ARTICLE IV

                         REPRESENTATIONS AND WARRANTIES

      Section 4.01. Representations and Warranties. Each of the Borrower and the
Project Company represents and warrants that the following are true and correct
in all material respects:

      (a) each of the Borrower and the Project Company is a company duly
incorporated and validly existing under the laws of Mexico and has the corporate
power to own its assets, conduct its business as presently conducted and to
enter into, and comply with its obligations under, the Transaction Documents to
which it is a party or will, in the case of any Transaction Document not
executed as at the date of this Agreement, when that Transaction Document is
executed, have the corporate power to enter into, and comply with its
obligations under, that Transaction Document;

      (b) each Transaction Document to which the Borrower or the Project Company
is a party has been, or will be, duly authorized and executed by the Borrower or
the Project Company, as the case may be, and constitutes, or will when executed
constitute, a valid and legally binding obligation of the Borrower or the
Project Company or both, as applicable;

      (c) neither the making of any Transaction Document or Project Document to
which either of the Borrower or the Project Company is a party nor the
compliance with its terms will conflict with or result in a breach of any of the
terms, conditions or provisions of, or constitute a default or require any
consent under, any indenture, mortgage, agreement or other instrument or
arrangement to which the Borrower or the Project Company is a party or by which
it is bound, or violate any of the terms or

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 34 -

provisions of the Borrower's or the Project Company's Charter or any
Authorization, judgment, decree or order or any statute, rule or regulation
applicable to the Borrower or the Project Company;

      (d) to the best of their knowledge, after due inquiry, all Authorizations
(other than Authorizations that are of a routine nature and are obtained in the
ordinary course of business) needed by either of the Borrower or the Project
Company to conduct its business, carry out the Project and execute, and comply
with its obligations under, this Agreement and each of the other Transaction
Documents to which it or the Project Company is a party have been obtained and
are in full force and effect;

      (e) neither the Borrower's Charter nor the Project Company's Charter has
been amended since December 7, 2000 and October 5, 1999, respectively;

      (f) neither the Borrower nor the Project Company nor any of their
respective properties enjoys any right of immunity from set-off, suit or
execution with respect to its assets or its obligations under any Transaction
Document to which the Borrower or the Project Company is a party;

      (g) [reserved];

      (h) since September 30, 2004 neither the Borrower nor the Project Company:

            (i)   has suffered any change that has a Material Adverse Effect or
                  incurred any substantial loss or liability;

            (ii)  has undertaken or agreed to undertake any substantial
                  obligation other than pursuant to the Transaction Documents;

      (i) the Consolidated financial statements of the Borrower for the period
ending on September 30, 2004:

            (i)   have been prepared in accordance with the Accounting
                  Principles, and present fairly the financial condition of the
                  Borrower as of the date as of which they were prepared and the
                  results of the Borrower's operations during the period then
                  ended;

            (ii)  disclose all liabilities (contingent or otherwise) of the
                  Borrower, and the reserves, if any, for such liabilities and
                  all unrealized or anticipated liabilities and losses arising
                  from commitments entered into by the Borrower (whether or not
                  such commitments have been disclosed in such financial
                  statements);

      (j) neither the Borrower nor the Project Company is a party to, or
committed to enter into, any contract which would or might affect the judgment
of a prospective investor;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 35 -

      (k) neither the Borrower nor the Project Company has outstanding Liens on
any of its assets other than Liens arising by operation of law, and no contracts
or arrangements, conditional or unconditional, exist for the creation by the
Borrower or the Project Company of any Lien, except for the Security and the GoM
Lien;

      (l) all tax returns and reports of each of the Borrower and the Project
Company required by law to be filed have been duly filed and all Taxes,
obligations, fees and other governmental charges upon the Borrower or the
Project Company, or their respective properties, or their respective income or
assets, which are due and payable or to be withheld, have been paid or withheld,
other than those presently payable without penalty or interest, and those being
contested in good faith by appropriate proceedings so long as:

            (A)   those proceedings do not involve any substantial danger of the
                  sale, forfeiture or loss of any part of the Project, title
                  thereto or any interest therein, nor interfere in any material
                  respect with the use or disposition thereof or the
                  implementation of the Project or the carrying on of the
                  business of the Borrower or the Project Company; and

            (B)   each of the Borrower and the Project Company has set aside
                  adequate reserves sufficient to promptly pay in full any
                  amounts that it may be ordered to pay on final determination
                  of any such proceedings;

      (m) neither the Borrower nor the Project Company is engaged in nor, to the
best of its knowledge, threatened by, any litigation, arbitration or
administrative proceedings, the outcome of which could reasonably be expected to
have a Material Adverse Effect;

      (n) to the best of its knowledge and belief, after due inquiry, neither
the Borrower nor the Project Company is in violation of any statute or
regulation of any Authority;

      (o) no judgment or order has been issued which has or may reasonably be
expected to have a Material Adverse Effect;

      (p) except as identified in the Environmental Assessment Report:

            (i)   to the best of its knowledge and belief, after due inquiry,
                  neither the Borrower nor the Project Company is in violation
                  of any of the Environmental, Health and Safety Guidelines or
                  of the Environmental and Social Policies; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 36 -

            (ii)  neither the Borrower nor the Project Company has received or
                  is aware of any complaint, order, directive, claim, citation
                  or notice from any Authority with respect to any matter of the
                  Borrower's or the Project Company's compliance with the
                  relevant environmental, health and safety laws and regulations
                  in effect in Mexico such as, without limitation, air
                  emissions, discharges to surface water or ground water, noise
                  emissions, solid or liquid waste disposal, or the use,
                  generation, storage, transportation or disposal of toxic or
                  hazardous substances or wastes;

      (q) none of the Borrower, the Project Company, the Sponsor or any
Affiliate, nor any Person acting on the Borrower's, the Project Company's, the
Sponsor's or any Affiliate's behalf, has made, with respect to the Project or
any transaction contemplated by this Agreement, any Prohibited Payment;

      (r) neither the Borrower nor the Project Company has entered into any
agreement to amend or otherwise modify the terms of the Concession Agreement;
and

      (s) none of the representations and warranties in this Section 4.01 omits
any matter the omission of which makes any of such representations and
warranties misleading.

      Section 4.02. IFC Reliance. Each of the Borrower and the Project Company
acknowledges that it makes the representations and warranties in Section 4.01
with the intention of inducing IFC to enter into this Agreement (and the
Participants to enter into the Participation Agreements) and that IFC enters
into this Agreement (and the Participants will enter into the Participation
Agreements) on the basis of, and in full reliance on, each of such
representations and warranties.

                                    ARTICLE V

                           CONDITIONS OF EFFECTIVENESS

      Section 5.01. Conditions of Effectiveness. The amendment and restatement
of the Original IFC Loan Agreement set forth in this Agreement shall become
effective only upon the fulfillment of the following conditions (and prior to
the fulfillment thereof, the Original IFC Loan Agreement as in existence prior
to the amendment and restatement contemplated hereby shall remain in full force
and effect):

      (a) the following agreements and amendments, each in form and substance
satisfactory to IFC, have been entered into by all parties to them and have
become (or, as the case may be, remain) unconditional and fully effective in
accordance with their respective terms (except for this Agreement or any one of
such documents having

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 37 -

become unconditional and fully effective, if that is a condition of any of such
documents, it being the intention of the parties that all of such documents
shall become effective simultaneously), and IFC has received a copy of each of
those agreements to which it is not a party:

            (i)   the Financial Support Agreement;

            (ii)  the FMO Loan Agreement;

            (iii) the Sponsor Guarantee Agreement; and

            (iv)  an amendment to the Put Option Agreement, providing for the
                  extension of the put period thereunder to December 31, 2012;

      (b) IFC has received from the Borrower a prepayment of the A Loan in the
amount of two hundred nineteen thousand one hundred sixty three and 64/100th
Dollars ($219,163.64);

      (c) IFC has received from the Borrower a prepayment of the B Loan in the
amount of two hundred eight thousand seven hundred twenty-seven and 27/100th
Dollars ($208,727.27);

      (d) IFC has received a legal opinion from the Borrower's counsel in
Mexico, in form and substance satisfactory to IFC, with regard to Mexican tax
law as it relates to (i) the Merger and (ii) the railroad diesel tax credit;

      (e) IFC has received a legal opinion from its special counsel in New York,
New York, in form and substance satisfactory to IFC, with regard to the New York
law aspects of this Agreement and the other Transaction Documents referred to in
subsection (a) above;

      (f) IFC has received a legal opinion from the Borrower's counsel in
Mexico, in form and substance satisfactory to IFC, with regard to the due
organization, power and authority of the Borrower and the Project Company to
enter into this Agreement and the other Transaction Documents referred to in
subsection (a) above to which it is a party and covering such other matters
relating to the transactions contemplated hereby and thereby as IFC may
reasonably request;

      (g) IFC has received a legal opinion from the Sponsor's general counsel,
in form and substance satisfactory to IFC, with regard to the Sponsor's due
organization, power and authority to enter into the Financial Support Agreement,
the Sponsor Guarantee Agreement and the amendment to the Put Option Agreement
and covering such other matters relating to the transactions contemplated hereby
and thereby as IFC may reasonably request;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 38 -

      (h) IFC has received any fees under Section 3.08(b)(vi) (Fees) required to
be paid in connection with the execution of this Agreement and the transactions
contemplated hereby;

      (i) IFC has received the reimbursement of all invoiced fees and expenses
of IFC's counsel incurred in connection with the execution of this Agreement and
the transactions contemplated hereby (as provided in Section
3.15(b)(ii)(H)(Expenses)), or confirmation that those fees and expenses have
been paid directly to that counsel;

      (j) each Existing Deficiency Loan Agreement has been amended to provide
for repayment of the relevant deficiency loan on the later of (i) the repayment
in full of both the FMO Loan and the IFC Loan and (ii) (in equal installments)
on March 15, 2013 and September 15, 2013; and

      (k) the Borrower and the Project Company have certified to IFC, in the
form of Schedule 2, that the representations and warranties made in Article IV
hereof are true and correct in all material respects as of the date upon which
all of the foregoing conditions have been satisfied.

      Section 5.02. IFC Notice; Amendment and Restatement; Conditions for IFC's
Benefit. (a) Upon the fulfillment of the conditions listed in Section 5.01, IFC
shall send notice to the Borrower, the Project Company, the Sponsor and FMO, in
the form of Schedule 3, stating that this Agreement has become effective.

      (b) The Borrower, the Project Company and IFC have agreed to remove the
conditions to disbursement that had been included in Article V of the Original
IFC Loan Agreement prior to the amendment and restatement contemplated by this
Agreement. For the avoidance of doubt, such removal is without prejudice to any
claims that IFC may have under Section 7.02(f).

      (c) The conditions in Section 5.01 are for the benefit of IFC and may be
waived only by IFC at its sole discretion.

                                   ARTICLE VI

                              PARTICULAR COVENANTS

      Section 6.01. Affirmative Covenants. Unless IFC otherwise agrees, the
Borrower shall, and shall cause the Project Company to, and the Project Company
shall:

      (a) carry out the Project and cause the Project to be carried out, and
conduct its business with due diligence and efficiency and in accordance with
sound engineering, financial and business practices;

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                                     - 39 -

      (b) cause the financing specified in the Financial Plan to be applied
exclusively to the Project;

      (c) promptly install and maintain an accounting and control system,
management information system and books of account and other records, which
together adequately reflect truly and fairly the financial condition of each of
the Borrower and the Project Company and the results of each of the Borrower's
and the Project Company's operations in conformity with the Accounting
Principles;

      (d) maintain the Auditors, or appoint and maintain, or cause to be
appointed and maintained at all times a firm of internationally recognized
independent public accountants acceptable to IFC as auditors of each of the
Borrower and the Project Company;

      (e) irrevocably authorize, in the form of Schedule 6, the Auditors (whose
fees and expenses shall be for the account of the Borrower) to communicate
directly with IFC at any time regarding the Borrower's Consolidated accounts and
operations, and provide to IFC a copy of that authorization, and, no later than
thirty (30) days after any change in Auditors, issue a similar authorization to
the new Auditors and provide a copy thereof to IFC;

      (f) upon IFC's request, such request to be made with reasonable prior
notice to the Borrower, except if an Event of Default or Potential Event of
Default has occurred and is continuing or if special circumstances so require,
permit representatives of IFC, during normal office hours, to:

            (i)   visit the Project site and any of the premises where the
                  business of the Borrower or the Project Company is conducted;

            (ii)  inspect all facilities, plant and equipment comprised in the
                  Project;

            (iii) have access to the Borrower's or the Project Company's books
                  of account and records; and

            (iv)  have access to those employees and agents of the Borrower or
                  the Project Company who have or may have knowledge of matters
                  with respect to which IFC seeks information;

      (g)   (i)   design, construct, operate, maintain and monitor all of its
                  equipment and facilities:

                  (A)   in accordance with the Environmental and Social Policies
                        and the Environmental, Health and Safety Guidelines; and

                  (B)   in compliance with the CAP, as well as applicable
                        environmental occupational health and safety
                        requirements,

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                                     - 40 -

                        and any child labor and forced labor laws, rules and
                        regulations (including any international treaty
                        obligations, if any) of the GoM and the local
                        authorities; and

            (ii)  not to effect any relocation of businesses and people residing
                  on the right-of-way granted to the Project Company under the
                  Concession Agreement without prior notification to IFC;

      (h) no later than thirty (30) days after the date of this Agreement but in
any event prior to the date of the IFC Disbursement:

            (i)   provide IFC with all information necessary to enable IFC to
                  update the document dated February 8, 2000, (specify reference
                  number) entitled Environmental Review Summary ("ERS") by
                  incorporating any modification or addition to that document
                  relating to the Project; and

            (ii)  display the updated ERS in appropriate public places in the
                  United Mexican States acceptable to IFC for public access;

            and IFC shall be entitled to place a copy of that updated ERS in the
            World Bank public information center known as InfoShop for public
            access;

      (i)   (A)   obtain and maintain, or cause to be obtained and maintained in
                  force (and where appropriate, renew, or cause to be renewed in
                  a timely manner) all Authorizations, including without
                  limitation the Authorizations specified in Annex A, which are
                  necessary for the implementation of the Project, the carrying
                  out of the Borrower's or the Project Company's business and
                  operations generally and the compliance by each of the
                  Borrower and the Project Company with all its obligations
                  under the Transaction Documents; and

            (B)   comply, or cause compliance, with all the conditions and
                  restrictions contained in, or imposed on the Borrower or the
                  Project Company by, those Authorizations;

      (j) from time to time, execute, acknowledge and deliver or cause to be
executed, acknowledged and delivered such further instruments as may reasonably
be requested by IFC for perfecting or maintaining in full force and effect the
Security or for re-registering the Security (including updating Exhibit A to
each of the Mercantile Pledge Agreements and pledging for the benefit of IFC,
after the date hereof, any Long-term Contracts) or otherwise to enable the
Borrower or the Project Company to comply with its obligations under the
Transaction Documents;

      (k) [reserved];

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      (l) comply with all its obligations under the Transaction Documents and
the Project Documents;

      (m) control the vegetation on the rights-of-way granted to the Project
Company under the Concession Agreement, consistent with the herbicide management
plan approved by IFC;

      (n) procure and purchase crossties only from suppliers approved by the GoM
so long as such approval is required;

      (o) [reserved];

      (p) implement the Project Company's internal guidelines relating to
illegal immigrants;

      (q) [reserved];

      (r) [reserved];

      (s) [reserved];

      (t) [reserved];

      (u) [reserved]; and

      (v) [reserved].

      Section 6.02. Negative Covenants Relating to the Borrower. Unless IFC
otherwise agrees, (I) before the Merger Effective Date, the Borrower shall not
take any of the actions set forth in subsections (a) through (w) below and (II)
after the Merger Effective Date, the Borrower shall not take any of the actions
set forth in subsections (s), (t) and (u) below (it being understood that
Section 6.03 (Negative Covenants Relating to the Project Company) shall also
apply to the Borrower after the Merger Effective Date, as set forth therein,
with references to the "Project Company" therein being deemed to be references
to the "Borrower"):

      (a) declare or pay any dividend or make any distribution on its share
capital (other than dividends or distributions payable in shares of the
Borrower), or purchase, redeem or otherwise acquire any shares of the Borrower
or any option over them, unless the proposed payment or distribution is out of
retained earnings and the Borrower, no earlier than sixty (60) days nor later
than thirty (30) days prior to doing so, certifies to IFC in writing, in the
form attached as Schedule 7, the sufficiency of such retained earnings and that:

            (i)   no Event of Default or Potential Event of Default has occurred
                  and is continuing;

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            (ii)  prior to the taking of any such action, the Borrower has made
                  prepayments under Section 3.07 (Prepayment) in a sufficient
                  amount, and such prepayments have been applied against the
                  remaining installments of the A Loan and B Loan in inverse
                  order of maturity (as required under Section 3.07(c)), such
                  that (A) the final installment of the A Loan under Section
                  3.06 (Repayment) is due no later than September 15, 2009 and
                  (B) the final installment of the B Loan under Section 3.06
                  (Repayment) is due no later than September 15, 2008; and

            (iii) after giving effect to any such action:

                  (A)   the Borrower's Current Ratio will be at least 1.0;

                  (B)   the Borrower's Long-term Debt to Tangible Net Worth
                        Ratio will be equal to or less than 2.0; and

                  (C)   the Borrower's Debt Service Coverage Ratio will not be
                        less than 1.4;

            provided always that:

                  (A)   the retained earnings out of which any of the payments
                        or distributions referred to in this subsection may be
                        made should in no event include any amount resulting
                        from the revaluation of any of the Borrower's assets;
                        and

                  (B)   the Borrower shall not make any payments or
                        distributions of the type referred to in this subsection
                        if, after giving effect to it, the Borrower could not
                        certify the matters referred to in Section 6.02(a)(i)
                        and (iii);

      (b) incur expenditures or commitments for expenditures for fixed or other
non-current assets;

      (c) incur, assume or permit to exist any Debt of the Borrower except:

            (i)   the Loans;

            (ii)  any subordinated Debt of the Borrower required or permitted
                  pursuant to this Agreement or the Financial Support Agreement;
                  and

            (iii) the credit line under the Credit Line Agreement but only until
                  the Merger occurs;

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                                     - 43 -

      (d) enter into any agreement or arrangement to lease any property or
equipment of any kind;

      (e) enter into any Derivative Transaction or assume the obligations of any
party to any Derivative Transaction, except as contemplated in the FMO Loan
Agreement;

      (f) enter into any agreement or arrangement to guarantee or, in any way or
under any condition, assume or become obligated for all or any part of any
financial or other obligation of another Person;

      (g) create or permit to exist any Lien on any property, revenues or other
assets, present or future, of the Borrower, except for:

            (i)   the Security;

            (ii)  the naming of each of IFC and FMO as a loss payee/beneficiary
                  under the Borrower's insurance policies; and

            (iii) any Lien arising from any tax, assessment or other
                  governmental charge or other Lien arising by operation of law,
                  in each case if the obligation underlying any such Lien is not
                  yet due or, if due, is being contested in good faith by
                  appropriate proceedings so long as:

                  (A)   those proceedings do not involve any substantial danger
                        of the sale, forfeiture or loss of any part of the
                        Project, title thereto or any interest therein, nor
                        interfere in any material respect with the use or
                        disposition thereof or the implementation of the Project
                        or the carrying on of the business of the Borrower; and

                  (B)   the Borrower has set aside adequate reserves sufficient
                        to promptly pay in full any amounts that the Borrower
                        may be ordered to pay on final determination of any such
                        proceedings;

      (h) enter into any transaction except in the ordinary course of business
on the basis of arm's-length arrangements (including, without limitation,
transactions whereby the Borrower might pay more than the ordinary commercial
price for any purchase or might receive less than the full ex-works commercial
price (subject to normal trade discounts) for its products);

      (i) establish any sole and exclusive purchasing or sales agency;

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                                     - 44 -

      (j) enter into any partnership, profit-sharing or royalty agreement or
other similar arrangement whereby the Borrower's income or profits are, or might
be, shared with any other Person;

      (k) enter into any management contract or similar arrangement whereby its
business or operations are managed by any other Person;

      (l) form or have any Subsidiary other than the Project Company;

      (m) make or permit to exist loans or advances to, or deposits (except the
Borrower's equity investment in the Project Company as of the date hereof and
commercial bank deposits in the ordinary course of business) with, other Persons
or investments in any Person or enterprise (other than pursuant to the Financial
Support Agreement) other than short-term marketable securities acquired solely
to give temporary employment to its idle funds;

      (n) reduce its share capital or otherwise change its Charter in any manner
which would be inconsistent with the provisions of any Transaction Document;

      (o) change its Financial Year;

      (p) change the nature or scope of the Project or change the nature of its
present business or operations;

      (q) sell, transfer, lease or otherwise dispose of all or a substantial
part of its assets, whether in a single transaction or in a series of
transactions, related or otherwise;

      (r) undertake or permit any merger, spin-off, consolidation or
reorganization other than the Merger permitted under Article IX;

      (s) terminate, amend, grant any waiver or assignment with respect to any
provision of any of the Transaction Documents or Project Documents or any
agreements evidencing any loans provided under the Financial Support Agreement
(other than the amendment of the Existing Deficiency Loan Agreements described
in Section 5.01(j) (Conditions of Effectiveness));

      (t) prepay (whether voluntarily or involuntarily) or repurchase any
Long-term Debt of the Borrower (other than the Loans) pursuant to any provision
of any agreement or note with respect to that Long-term Debt unless:

            (i)   that Long-term Debt is refinanced using new Long-term Debt on
                  terms and conditions (as to interest rate, other costs and
                  tenor) at least as favorable to the Borrower as those of the
                  Long-term Debt being refinanced; or

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<PAGE>

                                     - 45 -

            (ii)  the Borrower gives IFC at least thirty (30) days' advance
                  notice of its intention to make the proposed prepayment and,
                  if IFC so requires, the Borrower contemporaneously prepays a
                  proportion of the Loans equivalent to the proportion of the
                  part of the Long-term Debt being prepaid, such prepayment to
                  be made in accordance with the provisions of Section 3.07
                  (Prepayment) except that there shall be no minimum amount or
                  advance notice period for that prepayment;

      (u) use the proceeds of any IFC Disbursement in the territories of any
country which is not a member of the World Bank or for reimbursements of
expenditures in those territories or for goods produced in or services supplied
from any such country;

      (v) make (or authorize or permit any Affiliate or any other Person acting
on its behalf to make) with respect to the Project or any transaction
contemplated by this Agreement, any Prohibited Payment. The Borrower further
covenants that should IFC notify the Borrower of its concerns that there has
been a violation of the provisions of this Section or of Section 4.01(q) of this
Agreement, it shall cooperate in good faith with IFC and its representatives in
determining whether such a violation has occurred, and shall respond promptly
and in reasonable detail to any notice from IFC, and shall furnish documentary
support for such response upon IFC's request; or

      (w) make any payments to its Affiliates except as permitted under any
Transaction Document or Project Document.

      Section 6.03. Negative Covenants Relating to the Project Company. Unless
IFC otherwise agrees, (I) before the Merger Effective Date, the Borrower shall
cause the Project Company not to, and the Project Company shall not take any of
the actions set forth in subsections (a) through (w) below and (II) after the
Merger Effective Date, the Borrower shall not take any of the actions set forth
in subsections (a) through (w) below, other than the actions set forth in
subsection (s) below (it being understood that the Borrower shall continue to be
subject instead to the comparable restrictions set forth in Section 6.02(s)
(Negative Covenants Relating to the Borrower)):

      (a) declare or pay any dividend or make any distribution on its share
capital (other than dividends or distributions payable in shares of the Project
Company), or purchase, redeem or otherwise acquire any shares of the Project
Company or any option over them, unless the proposed payment or distribution is
out of retained earnings and the Project Company, no earlier than sixty (60)
days nor later than thirty (30) days prior to doing so, certifies to IFC in
writing, in the form attached as Schedule 7, the sufficiency of such retained
earnings and that:

            (i)   no Event of Default or Potential Event of Default has occurred
                  and is continuing;

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            (ii)  prior to the taking of any such action, prepayments have been
                  made under Section 3.07 (Prepayment) in a sufficient amount,
                  and such prepayments have been applied against the remaining
                  installments of the A Loan and B Loan in inverse order of
                  maturity (as required under Section 3.07(c)), such that (A)
                  the final installment of the A Loan under Section 3.06
                  (Repayment) is due no later than September 15, 2009 and (B)
                  the final installment of the B Loan under Section 3.06
                  (Repayment) is due no later than September 15, 2008; and

            (iii) after giving effect to any such action:

                  (A)   the Project Company's Current Ratio will be at least
                        1.0;

                  (B)   the Project Company's Long-term Debt to Tangible Net
                        Worth Ratio will be equal to or less than 2.0; and

                  (C)   the Project Company's Debt Service Coverage Ratio will
                        not be less than 1.4;

            provided always that:

                  (A)   the retained earnings out of which any of the payments
                        or distributions referred to in this subsection may be
                        made should in no event include any amount resulting
                        from the revaluation of any of the Project Company's
                        assets; and

                  (B)   the Project Company shall not make any payments or
                        distributions of the type referred to in this subsection
                        if, after giving effect to it, the Project Company could
                        not certify the matters referred to in Section
                        6.03(a)(i) and (iii);

      (b) subject to the provisions of the Financial Support Agreement and
Section 6.03(w) below, incur expenditures or commitments for expenditures for
fixed or other non-current assets, other than those required for carrying out
the Project or necessary for repairs, replacements and maintenance of
satisfactory operating conditions that are essential to the Project Company's
business or operations;

      (c) incur, assume or permit to exist any Debt of the Project Company
except:

            (i)   any subordinated Debt of the Project Company required or
                  permitted pursuant to this Agreement or the Financial Support
                  Agreement;

            (ii)  trade accounts incurred in the normal course of business and
                  not overdue by more than 90 days;

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<PAGE>

                                     - 47 -

            (iii) Short-term Debt of the Project Company incurred in the
                  ordinary course of business which, when aggregated with
                  contingent liabilities arising from the discounting of trade
                  receivables, would not exceed at any one time outstanding the
                  aggregate of the Project Company's receivables, inventories,
                  cash and short-term deposits;

            (iv)  loans to the Borrower pursuant to the Credit Line Agreement;
                  and

            (v)   after the Merger, the Loans;

      (d) enter into any agreement or arrangement to lease any property or
equipment of any kind, except leases with respect to which the aggregate lease
payments do not exceed the equivalent of one million Dollars ($1,000,000.00) in
any Financial Year;

      (e) enter into any Derivative Transaction or assume the obligations of any
party to any Derivative Transaction, except as contemplated in the FMO Loan
Agreement;

      (f) enter into any agreement or arrangement to guarantee or, in any way or
under any condition, assume or become obligated for all or any part of any
financial or other obligation of another Person other than the IFC Guarantee and
the FMO Guarantee;

      (g) create or permit to exist any Lien on any property, revenues or other
assets, present or future, of the Project Company, except for:

            (i)   the Security;

            (ii)  the GoM Lien;

            (iii) the naming of each of IFC and FMO as a loss payee/beneficiary
                  under the Project Company's insurance policies; and

            (iv)  any Lien arising from any tax, assessment or other
                  governmental charge or other Lien arising by operation of law,
                  in each case if the obligation underlying any such Lien is not
                  yet due or, if due, is being contested in good faith by
                  appropriate proceedings so long as:

                  (A)   those proceedings do not involve any substantial danger
                        of the sale, forfeiture or loss of any part of the
                        Project, title thereto or any interest therein, nor
                        interfere in any material respect with the use or
                        disposition thereof or the implementation of the Project
                        or the carrying on of the business of the Project
                        Company; and

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<PAGE>

                                     - 48 -

                  (B)   the Project Company has set aside adequate reserves
                        sufficient to promptly pay in full any amounts that the
                        Project Company may be ordered to pay on final
                        determination of any such proceedings;

      (h) enter into any transaction with its Affiliates or any other Person
except in the ordinary course of business on the basis of arm's-length
arrangements (including, without limitation, transactions whereby the Project
Company might pay more than the ordinary commercial price for any purchase or
might receive less than the full ex-works commercial price (subject to normal
trade discounts) for its products) except as otherwise permitted under the
Project Documents;

      (i) establish any sole and exclusive purchasing or sales agency;

      (j) enter into any partnership, profit-sharing or royalty agreement or
other similar arrangement whereby the Project Company's income or profits are,
or might be, shared with any other Person;

      (k) enter into any management contract or similar arrangement (except for
the Technical Assistance Agreement) whereby its business or operations are
managed by any other Person;

      (l) form or have any Subsidiary;

      (m) make or permit to exist loans or advances to, or deposits (except
commercial bank deposits in the ordinary course of business) with, other Persons
or investments in any Person or enterprise (except for loans to the Borrower
pursuant to the Credit Line Agreement) other than short-term marketable
securities acquired solely to give temporary employment to its idle funds;

      (n) change its Charter in any manner which would be inconsistent with the
provisions of any Transaction Document;

      (o) change its Financial Year;

      (p) change the nature or scope of the Project or change the nature of its
present or contemplated business or operations;

      (q) sell, transfer, lease or otherwise dispose of all or a substantial
part of its assets, whether in a single transaction or in a series of
transactions, related or otherwise;

      (r) undertake or permit any merger, spin-off, consolidation or
reorganization, other than the Merger permitted under Article IX;

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                                     - 49 -

      (s) withdraw from, terminate, amend or grant any waiver with respect to
any provision of any Project Document or Transaction Document or consent to an
assignment of any part thereof;

      (t) transfer or assign all or any part of the Concession Agreement or any
permit and/or license relating to the Project;

      (u) make any payment to its Affiliates except as permitted under any
Transaction Document or Project Document;

      (v) make (or authorize or permit any Affiliate or any other Person acting
on its behalf to make) with respect to the Project or any transaction
contemplated by this Agreement, any Prohibited Payment. The Project Company
further covenants that should IFC notify the Project Company of its concerns
that there has been a violation of the provisions of this Section or of Section
4.01(q) of this Agreement, it shall cooperate in good faith with IFC and its
representatives in determining whether such a violation has occurred, and shall
respond promptly and in reasonable detail to any notice from IFC, and shall
furnish documentary support for such response upon IFC's request; or

      (w) beginning in the Financial Year during which the Sponsor's obligation
to make Investment Overrun Loans (as such term is defined in the Financial
Support Agreement) terminates in accordance with Section 2.04(b) of the
Financial Support Agreement, if such obligation terminates, incur expenditures
for Capital Investments (as such term is defined in the Financial Support
Agreement) unless those expenditures do not exceed an aggregate amount in any
Financial Year equivalent to sixty percent (60%) of the Project Company's EBITDA
for such Financial Year.

      Section 6.04. Reporting Requirements. Unless IFC otherwise agrees, the
Borrower shall:

      (a) as soon as available but in any event within sixty (60) days after the
end of each quarter of each Financial Year, deliver to IFC:

            (i)   two (2) copies of the Borrower's complete financial statements
                  for such quarter prepared, on an unconsolidated basis and on a
                  Consolidated Basis, in accordance with the Accounting
                  Principles;

            (ii)  [reserved];

            (iii) a report on any factors that have or could reasonably be
                  expected to have a Material Adverse Effect;

            (iv)  a management report, including revenue by main client,
                  tariffs, the Project Company's intermodal and maintenance
                  activities, operating cost; and

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<PAGE>

                                     - 50 -

            (v)   a statement of all transactions during that quarter between
                  each of the Borrower and the Project Company and their
                  respective Affiliates, if any, and a certification by an
                  Authorized Representative that those transactions were on the
                  basis of arm's-length arrangements;

      (b) as soon as available but in any event within one hundred and twenty
(120) days after the end of each Financial Year, deliver to IFC:

            (i)   two (2) copies of its complete and audited financial
                  statements for that Financial Year (which are in agreement
                  with its books of account and prepared, on an unconsolidated
                  basis and Consolidated Basis, in accordance with the
                  Accounting Principles), together with the Auditors' audit
                  report on them, all in form satisfactory to IFC;

            (ii)  a management letter and such other communication from the
                  Auditors commenting, with respect to that Financial Year, on,
                  among other things, the adequacy of the Borrower's and the
                  Project Company's financial control procedures, accounting
                  systems and management information system;

            (iii) a report by the Auditors certifying that, on the basis of its
                  financial statements, each of the Borrower and the Project
                  Company was in compliance with the covenants contained in
                  Section 6.02 (Negative Covenants Relating to the Borrower) and
                  Section 6.03 (Negative Covenants Relating to the Project
                  Company), respectively, as of the end of that Financial Year
                  or, as the case may be, detailing any non-compliance;

            (iv)  a report by each of the Borrower and the Project Company on
                  its operations during that Financial Year, in the form of, and
                  addressing the topics listed in, Schedule 9;

            (v)   a statement by each of the Borrower and the Project Company of
                  all transactions between each of them and their respective
                  Affiliates, if any, during that Financial Year, and a
                  certification by an Authorized Representative that those
                  transactions were on the basis of arm's-length arrangements;
                  and

            (vi)  starting with the Financial Year ending on December 31, 2005,
                  a report by the Borrower setting forth the calculations for
                  such Financial Year of: (A) the railroad diesel taxes paid;
                  (B) the amount of the railroad diesel tax credit actually
                  credited to other tax obligations; and (C) the amount of the
                  railroad diesel tax credit that cannot be credited to other
                  tax obligations because of an

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                                     - 51 -

                  insufficient amount of applicable taxes against which it could
                  be credited, together with the Auditors' verification of such
                  calculations;

      (c) deliver to IFC, promptly following receipt, a copy of any management
letter or other communication sent by the Auditors (or any other accountants
retained by the Borrower) to either of the Borrower or the Project Company or
their management in relation to the Borrower's and the Project Company's
financial, accounting and other systems, management or accounts, if not provided
pursuant to Section 6.04(b)(ii);

      (d) within ninety (90) days after the end of each Financial Year, cause
the Project Company to deliver to IFC an annual monitoring report in the form of
Schedule 10, confirming compliance with the applicable national or local
requirements, the Environmental and Social Policies, the Environmental, Health
and Safety Guidelines, and the CAP and Sections 6.01(g) and 6.01(h) or, as the
case may be, detailing any non-compliance together with (A) the action being
taken to ensure compliance and (B) a written report verifying the contents of
that annual monitoring report, prepared by an independent third party consultant
of the Project Company, acceptable to IFC;

      (e) as soon as possible but no later than three (3) days after its
occurrence, notify IFC of any incident or accident which has or may reasonably
be expected to have an adverse effect on the environment, health or safety,
including, without limitation, explosions, spills or workplace accidents which
result in death, serious or multiple injury or major pollution, specifying, in
each case, the nature of the incident or accident, the on-site and off-site
impacts arising or likely to arise therefrom and the measures the Project
Company is taking or plans to take to address those impacts; and keep IFC
informed of the on-going implementation of those measures;

      (f) give notice to IFC, concurrently with the Borrower's or the Project
Company's notification to its shareholders, of any meeting of the Borrower's or
the Project Company's shareholders, such notice to include the agenda of the
meeting; and, as soon as available, deliver to IFC two (2) copies of:

            (i)   all notices, reports and other communications of the Borrower
                  or the Project Company, as the case may be, to its
                  shareholders, whether any such communication has been made on
                  an individual basis or by way of publication in a newspaper or
                  other communication medium; and

            (ii)  the minutes of all such shareholders' meetings;

      (g) promptly notify IFC of any proposed change in the nature or scope of
the Project or the business or operations of the Borrower or the Project Company
and of any event or condition which has or may reasonably be expected to have a
Material Adverse Effect;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 52 -

      (h) promptly upon becoming aware of any litigation or administrative
proceedings before any Authority or arbitral body which has or may reasonably be
expected to have a Material Adverse Effect, notify IFC by facsimile of that
event specifying the nature of that litigation or those proceedings and the
steps the Borrower or the Project Company, as the case may be, is taking or
proposes to take with respect thereto ;

      (i) promptly upon the occurrence of an Event of Default or Potential Event
of Default, notify IFC by facsimile specifying the nature of that Event of
Default or Potential Event of Default and any steps the Borrower or the Project
Company, as the case may be, is taking to remedy it;

      (j) promptly notify IFC (x) in the event the Borrower or the Project
Company receives a notification, fine, warning or other communication from the
GoM with respect to noncompliance by the Project Company with the terms of the
Concession Agreement, (y) in the event the Project Company fails to exercise any
of its rights under the Concession Agreement for a period of thirty (30) days,
or (z) of any other action which, pursuant to the terms of the Concession
Agreement, if left unresolved or with the passage of time, could result in the
termination, suspension or revocation of the Concession Agreement;

      (k) cause the Project Company to provide to IFC, in a timely manner, the
insurance certificates and other information referred to in Section 6.05 (d)
(Insurance);

      (l) promptly provide to IFC such other information as IFC may from time to
time reasonably request about the Borrower and the Project Company, their
respective assets and the Project; and

      (m) as soon as available but in any event within one hundred and twenty
(120) days after June 30 and December 31 in each Financial Year, deliver to IFC:

            (i)   two (2) copies of the Sponsor's complete financial statements
                  for such period prepared on a Consolidated Basis in accordance
                  with the Accounting Principles, which (A) in the case of the
                  financial statements delivered in respect of June 30, shall be
                  unaudited and cover the six-month period ending on June 30 and
                  (B) in the case of the financial statements delivered in
                  respect of December 31, shall be audited and cover the
                  Financial Year ending on such date; and

            (ii)  a statement of the outstanding amount (measured as of the
                  relevant June 30 or December 31) of all liabilities of any
                  Person (other than itself) which the Sponsor has guaranteed or
                  otherwise directly or indirectly obligated itself to pay;

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 53 -

provided, that such financial or other statements need not be delivered if and
to the extent that corresponding financial statements have been filed with the
United States Securities and Exchange Commission and are publicly available.

      Section 6.05. Insurance.

      (a) Insurance Requirements and Borrower's and Project Company's
Undertakings. Unless IFC otherwise agrees, the Borrower shall cause the Project
Company to, and the Project Company (and, after the Merger Effective Date, the
Borrower) shall:

            (i)   insure and keep insured, with financially sound and reputable
                  insurers, all its assets and business against all insurable
                  losses to include the insurances specified in Annex B and any
                  insurance required by law;

            (ii)  punctually pay any premium, commission and any other amounts
                  necessary for effecting and maintaining in force each
                  insurance policy;

            (iii) promptly notify the relevant insurer of any claim by the
                  Project Company (or, after the Merger Effective Date, the
                  Borrower) under any policy written by that insurer and
                  diligently pursue that claim;

            (iv)  comply with all warranties under each policy of insurance;

            (v)   not do or omit to do, or permit to be done or not done,
                  anything which might prejudice its, or, where IFC is loss
                  payee or an additional named insured, IFC's right to claim or
                  recover under any insurance policy; and

            (vi)  not vary, rescind, terminate, cancel or cause a material
                  change to any insurance policy;

            provided always that if at any time and for any reason any insurance
            required to be maintained under this Agreement shall not be in full
            force and effect, then IFC shall thereupon or at any time while the
            same is continuing be entitled (but have no such obligation) on its
            own behalf to procure that insurance at the expense of the Project
            Company (and, after the Merger Effective Date, at the expense of the
            Borrower) and to take all such steps to minimize hazard as IFC may
            consider expedient or necessary.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 54 -

      (b) Policy Provisions. Each insurance policy required to be obtained
pursuant to this Section shall be on terms and conditions acceptable to IFC, and
shall contain provisions to the effect that:

            (i)   no policy can expire nor can it be canceled or suspended by
                  the Project Company (or, after the Merger Effective Date, the
                  Borrower) or the insurer for any reason (including failure to
                  renew the policy or to pay the premium or any other amount)
                  unless IFC and, in the case of expiration or if cancellation
                  or suspension is initiated by the insurer, the Project Company
                  (and, after the Merger Effective Date, the Borrower) receive
                  at least forty-five (45) days' notice (or such lesser period
                  as IFC may agree with respect to cancellation, suspension or
                  termination in the event of war and kindred peril) prior to
                  the effective date of termination, cancellation or suspension;

            (ii)  IFC and all contractors working at the Project site are named
                  as additional named insured on all liability policies;

            (iii) where relevant, all its provisions (except those relating to
                  limits of liability) shall operate as if they were a separate
                  policy covering each insured party; and

            (iv)  on every insurance policy on the Project Company's (and, after
                  the Merger Effective Date, the Borrower's) assets which are
                  the subject of the Security and for business interruption or
                  delayed start-up, IFC is named as a loss payee for any claim
                  of, or any series of claims arising with respect to the same
                  event whose aggregate amount is, the equivalent of five
                  hundred thousand Dollars ($500,000) or more;

      (c) Application of Proceeds.

            (i)   At its discretion, IFC may remit the proceeds of any insurance
                  paid to it to the Project Company (or, after the Merger
                  Effective Date, the Borrower) to repair or replace the
                  relevant damaged assets or may apply those proceeds towards
                  any amount payable to IFC under this Agreement, including to
                  repay or prepay all or any part of the IFC Loan in accordance
                  with Section 3.07 (Prepayment); provided that there shall be
                  no minimum amount or notice period for any such prepayment.

            (ii)  The Project Company (and, after the Merger Effective Date, the
                  Borrower) shall use any insurance proceeds it receives
                  (whether from IFC or directly from the insurers) for loss of
                  or damage to any asset solely to replace or repair that asset.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 55 -

      (d) Reporting Requirements. Unless IFC otherwise agrees, the Borrower
shall cause the Project Company to, and the Project Company (and, after the
Merger Effective Date, the Borrower) shall provide to IFC the following:

            (i)   as soon as possible after its occurrence, notice of any event
                  which entitles the Project Company (and, after the Merger
                  Effective Date, the Borrower) to claim for an aggregate amount
                  exceeding the equivalent of five hundred thousand Dollars
                  ($500,000) under any one or more insurance policies;

            (ii)  within forty-five (45) days after the main insurance policy is
                  issued to the Project Company (and, after the Merger Effective
                  Date, the Borrower), a copy of that policy incorporating any
                  loss payee provisions required under Section 6.05 (b) (iv)
                  (unless that policy has already been provided to IFC);

            (iii) not less than ten (10) days prior to the expiry date of any
                  insurance policy (or, for insurance with multiple renewal
                  dates, not less than ten (10) days prior to the expiry date of
                  the policy on the principal asset), a certificate of renewal
                  from the insurer, insurance broker or agent confirming the
                  renewal of that policy and the renewal period, the premium,
                  the amounts insured for each asset or item and any changes in
                  terms or conditions from the policy's issue date or last
                  renewal, and confirmation from the insurer that provisions
                  naming IFC as a loss payee or additional named insured, as
                  applicable, remain in effect;

            (iv)  such evidence of premium payment as IFC may from time to time
                  request; and

            (v)   any other information or documents on each insurance policy as
                  IFC request from time to time.

                                   ARTICLE VII

                                EVENTS OF DEFAULT

      Section 7.01. Acceleration after Default. If any Event of Default occurs
and is continuing (whether it is voluntary or involuntary, or results from
operation of law or otherwise), IFC may, by notice to the Borrower, require the
Borrower to repay the IFC Loan or such part of the IFC Loan as is specified in
that notice. On receipt of any such notice, the Borrower shall immediately repay
the IFC Loan (or that part of the IFC Loan

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 56 -

specified in that notice) and pay all interest accrued on it and any other
amounts then payable under this Agreement. The Borrower waives any right it
might have to further notice, presentment, demand or protest with respect to
that demand for immediate payment.

      Section 7.02. Events of Default. It shall be an Event of Default if:

      (a) the Borrower fails to pay when due any part of the principal of, or
interest on, the IFC Loan and such failure continues for a period of five (5)
days;

      (b) the Borrower fails to pay when due any part of the principal of, or
interest on, the FMO Loan and such failure continues for a period of five (5)
days;

      (c) the Borrower fails to pay when due any part of the principal of, or
interest on, any loan from IFC to the Borrower other than the IFC Loan and any
such failure continues for the relevant period of grace provided for in the
agreement providing for that loan;

      (d) the Borrower or the Project Company fails to comply with any of its
obligations under this Agreement or any other Transaction Document or any other
agreement between the Borrower and/or the Project Company and IFC (other than
for the payment of the principal of, or interest on, the IFC Loan or any other
loan from IFC to the Borrower), and any such failure continues for a period of
thirty (30) days after the earlier of the date on which (i) IFC notifies the
Borrower or the Project Company of that failure, or (ii) the Borrower or the
Project Company becomes aware of such failure;

      (e) any party to a Transaction Document (other than IFC or the Borrower)
or a Project Document fails to observe or perform any of its obligations under
that Transaction Document or Project Document, and any such failure continues
for a period of thirty (30) days after the earlier of the date on which (i) IFC
notifies the Borrower or the Project Company of that failure, or (ii) the
Borrower or the Project Company becomes aware of such failure;

      (f) any representation or warranty made in Article IV or in connection
with the execution of, or any request (including a request for Disbursement)
under, this Agreement or any other Transaction Document is found to be incorrect
in any material respect;

      (g) any Authority condemns, nationalizes, seizes, or otherwise
expropriates all or any substantial part of the property or other assets of the
Borrower or of its share capital, or assumes custody or control of that property
or other assets or of the business or operations of the Borrower or of its share
capital, or takes any action for the dissolution or disestablishment of the
Borrower or any action that would prevent the Borrower or its officers from
carrying on all or a substantial part of its business or operations;

      (h) a decree or order by a court is entered against the Borrower:

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 57 -

            (i)   adjudging the Borrower bankrupt or insolvent;

            (ii)  approving as properly filed a petition seeking reorganization,
                  arrangement, adjustment or composition of, or with respect to,
                  the Borrower under any applicable law;

            (iii) appointing a receiver, liquidator, assignee, trustee,
                  sequestrator (or other similar official) of the Borrower or of
                  any substantial part of its property or other assets; or

            (iv)  ordering the winding up or liquidation of its affairs;

or any petition is filed seeking any of the above and is not dismissed within
thirty (30) days;

      (i)   the Borrower:

            (i)   requests a moratorium or suspension of payment of debts from
                  any court;

            (ii)  institutes proceedings or takes any form of corporate action
                  to be liquidated, adjudicated bankrupt or insolvent;

            (iii) consents to the institution of bankruptcy or insolvency
                  proceedings against it;

            (iv)  files a petition or answer or consent seeking reorganization
                  or relief under any applicable law, or consents to the filing
                  of any such petition or to the appointment of a receiver,
                  liquidator, assignee, trustee, sequestrator (or other similar
                  official) of the Borrower or of any substantial part of its
                  property;

            (v)   makes a general assignment for the benefit of creditors; or

            (vi)  admits in writing its inability to pay its debts generally as
                  they become due or otherwise becomes insolvent;

      (j) an attachment or analogous process is levied or enforced upon or
issued against any of the assets of the Borrower for an amount in excess of the
equivalent of one million Dollars ($1,000,000) and is not discharged within
thirty (30) days;

      (k) any other event occurs which under any applicable law would have an
effect analogous to any of those events listed in Section 7.02 (g) through
Section 7.02 (i);

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 58 -

      (l) the Borrower or the Project Company fails to pay any of its Debt due
and payable in excess of five hundred thousand Dollars ($500,000) (other than
the IFC Loan or any other loan from IFC to the Borrower) or to perform any of
its obligations under any agreement pursuant to which there is outstanding any
Debt, and any such failure continues for more than any applicable period of
grace or any such Debt becomes prematurely due and payable or is placed on
demand;

      (m) any Authorization necessary for the Borrower or the Project Company to
perform and observe its obligations under any Transaction Document is not
obtained when required or is rescinded, terminated, lapses or otherwise ceases
to be in full force and effect, including with respect to the remittance to IFC
or its assignees, in Dollars, of any amounts payable under any Transaction
Document, and is not restored or reinstated within thirty (30) days of notice by
IFC to the Borrower requiring that restoration or reinstatement;

      (n) any Security Document or any of its provisions:

            (i)   is revoked, terminated or ceases to be in full force and
                  effect or ceases to provide the security intended, without, in
                  each case, the prior consent of IFC;

            (ii)  becomes unlawful or is declared void; or

            (iii) is repudiated or its validity or enforceability is challenged
                  by any Person and any such repudiation or challenge continues
                  for a period of thirty (30) days during which period such
                  repudiation or challenge has no effect;

      (o) any Transaction Document (other than a Security Document) or any of
its provisions:

            (i)   is revoked, terminated or ceases to be in full force and
                  effect without, in each case, the prior consent of IFC, and
                  that event, if capable of being remedied, is not remedied to
                  the satisfaction of IFC within thirty (30) days of IFC's
                  notice to the Borrower; or

            (ii)  becomes unlawful or is declared void;

      (p) any Transaction Document (other than a Security Document) is
repudiated or the validity or enforceability of any of its provisions at any
time is challenged by any Person and such repudiation or challenge is not
withdrawn within thirty (30) days of IFC's notice to the Borrower requiring that
withdrawal; provided that no such notice shall be required or, as the case may
be, the notice period shall terminate if and when such repudiation or challenge
becomes effective;

      (q) any Project Document:

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 59 -

            (i)   is breached by any party to it and such breach has or could
                  reasonably be expected to have a Material Adverse Effect; or

            (ii)  is revoked, amended, terminated or ceases to be in full force
                  and effect without the prior consent of IFC, or performance of
                  any of the material obligations under any such agreement
                  becomes unlawful or any such agreement is declared to be void
                  or is repudiated or its validity or enforceability at any time
                  is challenged by any party to it;

      (r) any of the events specified in Section 7.02 (g) through 7.02 (l)
occurs to the Sponsor or its properties, assets, or capital; provided, that, the
threshold under Section 7.02 (j) and Section 7.02 (l) shall be $2,000,000;

      (s) any of the events specified in Section 7.02(g) through 7.02(k) occurs
with respect to the Project Company or its properties, assets, or capital;

      (t) the Project Company fails to exercise any of its rights under the
Concession Agreement;

      (u) the Merger shall not have occurred by the Merger Deadline Date; or

      (v) GoM notifies the Project Company or IFC of its intention to terminate
the Concession Agreement.

      Section 7.03. Bankruptcy. If the Borrower or the Project Company is
liquidated or declared bankrupt, the IFC Loan, all interest accrued on it and
any other amounts payable under this Agreement will become immediately due and
payable without any presentment, demand, protest or notice of any kind, all of
which the Borrower waives.

                                  ARTICLE VIII

                                  MISCELLANEOUS

      Section 8.01. Saving of Rights. (a) The rights and remedies of IFC in
relation to any misrepresentation or breach of warranty on the part of the
Borrower and/or the Project Company shall not be prejudiced by any investigation
by or on behalf of IFC or any of the Participants into the affairs of the
Borrower and/or the Project Company, by the execution or the performance of this
Agreement or by any other act or thing which may be done by or on behalf of IFC
in connection with this Agreement and which might, apart from this Section,
prejudice such rights or remedies.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 60 -

      (b) No course of dealing or waiver by IFC in connection with any condition
of effectiveness of this Agreement shall impair any right, power or remedy of
IFC with respect to any other condition of effectiveness, or be construed to be
a waiver thereof.

      (c) No course of dealing and no failure or delay by IFC in exercising, in
whole or in part, any power, remedy, discretion, authority or other right under
this Agreement or any other agreement shall waive or impair, or be construed to
be a waiver of or an acquiescence in, such or any other power, remedy,
discretion, authority or right under this Agreement, or in any manner preclude
its additional or future exercise; nor shall the action of IFC with respect to
any default, or any acquiescence by it therein, affect or impair any right,
power or remedy of IFC with respect to any other default.

      (d) The Borrower, the Project Company and IFC have agreed to remove
certain provisions that had been included in the Original IFC Loan Agreement.
For the avoidance of doubt, such removal is without prejudice to any rights or
remedies arising from such provisions (i) which may have accrued to IFC prior to
the effectiveness of this Agreement and (ii) which may accrue to IFC on or after
the effectiveness of this Agreement with respect to the period prior thereto.

      Section 8.02. Notices. Any notice, request or other communication to be
given or made under this Agreement shall be in writing. Subject to Section 6.04
(i) and Section 6.04 (h) (Reporting Requirements) and Section 8.05 (c), any such
communication may be delivered by hand, airmail, facsimile or established
courier service to the party's address specified below or at such other address
as such party notifies to the other party from time to time, and will be
effective upon receipt. A notice, request or other communication (other than
under Article III) which is made by facsimile shall be confirmed by mail but
without prejudice to it being effective on receipt of the facsimile.

      For the Borrower:

                GW Servicios, S.A. de C.V.
                Calle 43 429-C
                Col. Industrial
                Merida, Yucatan
                97000
                Mexico

                Attention: Chief Financial Officer

                Alternative address for communications by facsimile:

                          011-529-930-2543

      For the Project Company:

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 61 -

                Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V.
                Calle 43 429-C
                Col. Industrial
                Merida, Yucatan
                97000
                Mexico

                Attention: Chief Financial Officer

                Alternative address for communications by facsimile:

                          011-529-930-2543

      For IFC:

                International Finance Corporation
                2121 Pennsylvania Avenue, N.W.
                Washington, D.C. 20433
                United States of America

                Facsimile: (202) 974-4310

                Attention: Director, Infrastructure Department

                With a copy (in the case of communications relating to
                payments) sent to the attention of the Senior Manager,
                Financial Operations Unit, at:

                Facsimile: 202-974-4371.

      Section 8.03. English Language. (a) All documents to be provided or
communications to be given or made under this Agreement shall be in the English
language.

      (b) To the extent that the original version of any document to be
provided, or communication to be given or made, to IFC under this Agreement or
any other Transaction Document is in a language other than English, that
document or communication shall be accompanied by an English translation
certified by an Authorized Representative to be a true and correct translation
of the original. IFC may, if it so requires, obtain an English translation of
any document or communication received in a language other than English at the
cost and expense of the Borrower. IFC may deem any such English translation to
be the governing version between the Borrower and IFC.

      Section 8.04. Term of Agreement. This Agreement shall continue in force
until all monies payable under it have been fully paid in accordance with its
provisions.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 62 -

      Section 8.05. Applicable Law and Jurisdiction. (a) This Agreement is
governed by, and shall be construed in accordance with, the laws of the State of
New York, United States of America.

      (b) Each of the parties hereby irrevocably submits to the jurisdiction of
any court of the United States of America located in the Southern District of
New York in any action or proceeding arising out of or relating to this
Agreement. By the execution and delivery of this Agreement each of the parties
hereby irrevocably submits to the jurisdiction of any such court and, except as
otherwise provided in Section 8.05 (e), hereby irrevocably waives the benefit of
jurisdiction derived from present or future domicile or otherwise in any such
action or proceeding; provided, that IFC's submission to jurisdiction as set
forth above does not constitute any waiver of its immunities under its Articles
of Agreement.

      (c) Each of the Borrower and the Project Company hereby irrevocably
designates, appoints and empowers CT Corporation System, 111 Eighth Avenue, 13th
Floor, New York, New York 10011, United States of America, as its authorized
agent to receive for and on its behalf service of summons or other legal process
in any such action or proceeding in New York, New York, United States of
America. Each of the Borrower and the Project Company agrees that the failure of
such agent to give notice to the Borrower or the Project Company of any such
service shall not impair or affect the validity of such service or of any
judgment rendered in any action or proceeding based thereon. Each of the
Borrower and the Project Company further irrevocably consents to the service of
process out of any such court by mailing copies thereof by registered United
States air mail postage prepaid to the Borrower or the Project Company at its
address specified herein. Final judgment against the Borrower or the Project
Company in any such action, suit or proceeding shall be conclusive and may be
enforced in any other jurisdiction, including Mexico, by suit on the judgment, a
certified or exemplified copy of which shall be conclusive evidence of the fact.
Nothing herein shall affect the right of IFC to serve process upon the Borrower
or the Project Company in any manner authorized by the laws of any such other
jurisdiction.

      (d) Each of the parties hereby irrevocably waives, to the fullest extent
permitted by law, any objection which it may now or hereafter have to the laying
of venue of any suit, action or proceeding arising out of or relating to this
Agreement brought in the courts of the United States of America located in the
Southern District of New York and hereby further irrevocably waives, to the
fullest extent permitted by law, any claim that any such suit, action or
proceeding brought in any such court has been brought in any inconvenient forum.
Each of the Borrower and the Project Company further covenants and agrees that,
until all monies actually or contingently payable hereunder shall have been
fully paid in accordance with the terms of this Agreement, it shall maintain
duly appointed agents for the service of summons and other legal process in New
York, New York, United States of America, for purposes of any legal action or
proceeding brought by IFC in respect of this Agreement and shall keep IFC
advised of the identity and location of such agents.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 63 -

      (e) Each of the Borrower and the Project Company hereby irrevocably agrees
that any legal action, suit or proceeding arising out of or relating to this
Agreement may be brought in the courts of the Federal District of Mexico at the
election of IFC without any requirement that IFC submit, based upon Article VI,
Section 11 of the Articles of Agreement of IFC, to the jurisdiction of such
courts in connection with any legal action, suit or proceeding arising out of or
relating to this Agreement that may be brought at the election of the Borrower
or the Project Company. By the execution and delivery of this Agreement, each of
the Borrower and the Project Company hereby irrevocably submits to the
jurisdiction of any such court and hereby irrevocably waives the benefit of
jurisdiction derived otherwise in any such action, suit or proceeding. Nothing
in this Agreement constitutes a waiver by IFC of any immunity to which IFC may
be entitled under the Articles of Agreement establishing IFC or under applicable
law.

      (f) Each of the Borrower and the Project Company irrevocably waives to the
fullest extent permitted by applicable law any and all rights to demand a trial
by jury in any action, suit or proceeding brought against the Borrower or the
Project Company by IFC.

      (g) To the extent that either the Borrower or the Project Company may be
entitled in any jurisdiction to claim for itself or its assets immunity in
respect of its obligations under this Agreement from any suit, execution,
attachment (whether provisional or final, in aid of execution, before judgment
or otherwise) or other legal process or to the extent that in any jurisdiction
such immunity (whether or not claimed) may be attributed to it or its assets, it
irrevocably agrees not to claim and irrevocably waives such immunity to the
fullest extent permitted by the laws of such jurisdiction.

      (h) Each of the Borrower and the Project Company hereby acknowledges that
IFC shall be entitled under applicable law, including the provisions of the
International Organizations Immunities Act, to immunity from a trial by jury in
any action, suit or proceeding arising out of or relating to this Agreement or
the transactions contemplated hereby brought against IFC in any court of the
United States of America. Each of the Borrower and the Project Company hereby
waives any and all rights to demand a trial by jury in any action, suit or
proceeding arising out of or relating to this Agreement or the transactions
contemplated by this Agreement, brought against IFC in any forum in which IFC is
not entitled to immunity from a trial by jury.

      (i) To the extent that either the Borrower or the Project Company may, in
any suit, action or proceeding brought in any of the courts referred to in
subsection (b) above or elsewhere (other than a court in Mexico) arising out of
or in connection with this Agreement be entitled to the benefit of any provision
of law requiring IFC in such suit, action or proceeding to post security for the
costs of the Borrower or the Project Company (cautio judicatum solvi), or to
post a bond or to take similar action, each of the Borrower and the Project
Company hereby irrevocably waives such benefit, in each case to the fullest
extent now or in the future permitted under the laws of the jurisdiction in
which such court is located.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 64 -

      Section 8.06. Disclosure of Information. (a) IFC may disclose any
documents or records of, or information about, this Agreement or any other
Transaction Document, or the assets, business or affairs of the Borrower to:

            (i)   its outside counsel, auditors and rating agencies,

            (ii)  any Person with a participation in or who intends to purchase
                  a participation in a portion of the IFC Loan, and

            (iii) any other Person as IFC may deem appropriate in connection
                  with any proposed sale, transfer, assignment or other
                  disposition of IFC's rights under this Agreement or any other
                  Transaction Document or otherwise for the purpose of
                  exercising any power, remedy, right, authority, or discretion
                  relevant to this Agreement or any other Transaction Document.

      (b) The Borrower acknowledges and agrees that, notwithstanding the terms
of any other agreement between the Borrower and IFC, a disclosure of information
by IFC in the circumstances contemplated by Section 8.06 (a) does not violate
any duty owed to the Borrower under this Agreement or under any such other
agreement.

      Section 8.07. Successors and Assignees. This Agreement binds and benefits
the respective successors and permitted assignees of the parties. However,
neither the Borrower nor the Project Company may, subject to Article IX, assign
or delegate any of its rights or obligations under this Agreement without the
prior consent of IFC. Any purported assignment or delegation in violation of
this Section shall be void.

      Section 8.08. Amendments, Waivers and Consents. Any amendment or waiver
of, or any consent given under, any provision of this Agreement shall be in
writing and, in the case of an amendment, signed by the parties.

      Section 8.09 Counterparts. This Agreement may be executed in several
counterparts, each of which is an original, but all of which together constitute
one and the same agreement.

                                   ARTICLE IX

                                   THE MERGER

      Section 9.01. Conditions Precedent of the Merger. The Merger shall be
subject to the following conditions precedent:

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 65 -

      (a)   the Borrower and the Project Company shall provide to IFC no less
            than six (6) months' prior notice in writing of the Merger;

      (b)   [reserved];

      (c)   the Borrower and the Project Company shall provide to IFC such other
            documents as IFC may reasonably request in connection with the
            Merger;

      (d)   the Borrower, the Project Company, and the Sponsor shall execute,
            acknowledge, deliver or cause to be executed, acknowledged and
            delivered such further instruments as IFC may reasonably request for
            perfecting the Security or otherwise to enable the Borrower, the
            Project Company or the Sponsor to comply with its obligations under
            the Transaction Documents; and

      (e)   IFC shall receive, at the expense of the Project Company, a legal
            opinion, satisfactory to IFC, from IFC's counsel in Mexico:

            (i)   confirming that the Merger is tax-free under the laws of
                  Mexico; all formalities have been fulfilled to ensure that the
                  Borrower shall assume all the obligations of the Project
                  Company under this Agreement, the Security Documents and other
                  Transaction Documents; all formalities have been fulfilled to
                  ensure that the Security is perfected; and

            (ii)  covering such other matters as IFC may reasonably request.

      Section 9.02. Acknowledgment of the Borrower. Without in any way limiting
the effect of the Merger under law, the Borrower acknowledges and agrees that,
on the Merger Effective Date, each and every obligation and liability of the
Project Company under this Agreement shall become the obligation and liability
of the Borrower, without any further action by any party hereto or any other
Person.

                            -signature page follows-

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 66 -

      IN WITNESS WHEREOF, the parties have caused this Agreement to be signed in
their respective names as of the date first above written.

                                  GW SERVICIOS, S.A. DE C.V.

                                  By : _________________________________________

                                  Name: ________________________________________

                                  Title : ______________________________________

                                  COMPANIA DE FERROCARRILES CHIAPAS-MAYAB,
                                  S.A. DE C.V.

                                  By : _________________________________________

                                  Name: ________________________________________

                                  Title : ______________________________________

                                  INTERNATIONAL FINANCE CORPORATION

                                  By : _________________________________________

                                  Name: ________________________________________

                                  Title : ______________________________________

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 67 -

                                                                      ANNEX A
                                                                     Page 1 of 1

                                   [reserved]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 68 -

                                                                      ANNEX B
                                                                     Page 1 of 1

                             INSURANCE REQUIREMENTS

                  (See Section 6.05 (a) of the Loan Agreement)

                         MINIMUM INSURANCE REQUIREMENTS

The company shall have the following insurances in place at all times as
applicable:

1.    CONSTRUCTION/REHABILITATION WORK

      a)    Construction All Risks, based on full contract value and including:

            i)      Riot and Strike

            ii)     Debris Removal

            iii)    Extra Expenses

            iv)     Maintenance

            v)      Third Party Liability for not less than $75 million

      b)    Marine all Risks (including war) in respect of all critical imports.

2.    OPERATIONAL PHASE

      a)    Fire and named perils or All Risks Insurance based on replacement
      value of all fixed assets

      b)    All Risks Insurance for full replacement value, or for 125% of PML
            as calculated by an experienced Insurance surveyor, on all movable
            assets including rolling stocks.

      c)    Business Interruption or Extra Expenses with an indemnity period of
            not less than 12 months

      d)    Third Party Liability, including Passenger and Goods Liability for
            not less than $ 75 million

3.    AT ALL TIMES

      Such insurances as required by local legislation or by contract

      Directors' and Officers' Liability insurance

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 69 -

                                                                       ANNEX C
                                                                     Page 1 of 1

                                   [reserved]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 70 -

                                                                      SCHEDULE 1
                                                                     Page 1 of 2

                 FORM OF CERTIFICATE OF INCUMBENCY AND AUTHORITY

                    (See Section 1.01 of the Loan Agreement)

                             [Borrower's Letterhead]

                                                                          [Date]

International Finance Corporation
2121 Pennsylvania Avenue, N.W.
Washington, D.C. 20433
United States of America

Attention: Director, Infrastructure Department

Ladies and Gentlemen:

                     Certificate of Incumbency and Authority

      With reference to the Loan Agreement among GW Servicios, S.A. de C.V. (the
"Borrower"), Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V. (the "Project
Company") and International Finance Corporation ("IFC"), dated December 5, 2000,
as amended and restated as of March 15, 2005 (the "Loan Agreement"), I, the
undersigned [Chairman/Director] of [GW Servicios, S.A. de C.V., (the
"Borrower")][Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V. (the "Project
Company")], duly authorized to do so, hereby certify that the following are the
names, offices and true specimen signatures of the persons [each] [any two] of
whom are, and will continue to be, authorized:

      (a) to sign the certifications provided for in Section 5.01(k) of the Loan
Agreement; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 71 -

                                                                      SCHEDULE 1
                                                                     Page 2 of 2

      (b) to take any other action required or permitted to be taken, done,
signed or executed under the Loan Agreement or any other agreement to which IFC
and the Borrower may be parties.

<TABLE>
<CAPTION>
*Name                          Office                         Specimen Signature
------------------------       ----------------------         ------------------
<S>                            <C>                            <C>
------------------------       ----------------------         ------------------

------------------------       ----------------------         ------------------

------------------------       ----------------------         ------------------
</TABLE>

      You may assume that any such person continues to be so authorized until
you receive authorized written notice from the Borrower that they, or any of
them, is no longer so authorized.

                                                   Yours truly,

                                                   [GW SERVICIOS, S.A. DE C.V.]
                                                   [COMPANIA DE FERROCARRILES
                                                   CHIAPAS-MAYAB, S.A. DE C.V.]

                                                   By ________________________
                                                         [Chairman/Director]

--------------------
*     Designations may be changed by the Borrower or the Project Company at any
      time by issuing a new Certificate of Incumbency and Authority authorized
      by the Board of Directors of the Borrower where applicable.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 72 -

                                                                     SCHEDULE 2
                                                                     Page 1 of 2

             FORM OF CERTIFICATION OF REPRESENTATIONS AND WARRANTIES

                   (See Section 5.01(k) of the Loan Agreement)

                             [Borrower's Letterhead]

                                                                 March ___, 2005

International Finance Corporation
2121 Pennsylvania Avenue, N.W.
Washington, D.C. 20433
United States of America

Attention: Director, Infrastructure Department

Ladies and Gentlemen:

                               Investment No. 9902

1. Please refer to the Loan Agreement (the "Loan Agreement") dated December 5,
2000, as amended and restated as of March 15, 2005, among GW Servicios, S.A. de
C.V. (the "Borrower"), Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V.
(the "Project Company") and International Finance Corporation ("IFC"). Terms
defined in the Loan Agreement have their defined meanings whenever used in this
request.

2. For the purpose of Section 5.01(k) of the Loan Agreement, the Borrower and
the Project Company certify that the representations and warranties made in
Article IV of the Loan Agreement are true and correct in all material respects
on the date of this certificate with the same effect as if such representations
and warranties had been made on and as of the date hereof.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 73 -

                                                                      SCHEDULE 2
                                                                     Page 2 of 2

      The above certification is effective as of the date of this Certificate.
If this certification is no longer valid as of or prior to the date of receipt
of the notice described in Section 5.02(a) from IFC, the Borrower and the
Project Company undertake to immediately notify the Senior Lenders.

                                               Yours truly,

                                               GW SERVICIOS, S.A. DE C.V.

                                               By ______________________________
                                                   Authorized Representative

                                               COMPANIA DE FERROCARRILES
                                               CHIAPAS-MAYAB, S.A. DE C.V.

                                               By ______________________________
                                                   Authorized Representative

Copy to: Manager, Financial Operations Unit
         International Finance Corporation

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 74 -

                                                                     SCHEDULE 3
                                                                     Page 1 of 1

                         FORM OF NOTICE OF EFFECTIVENESS

                   (See Section 5.02(a) of the Loan Agreement)

                                [IFC Letterhead]

                                                                 March ___, 2005

GW Servicios, S.A. de C.V.
Calle 43 429-C
Col. Industrial
Merida, Yucatan
97000
Mexico

Attention: Chief Financial Officer

Dear _____________:

                   Effectiveness of Amendment and Restatement
                      of Loan Agreement and Other Documents

      International Finance Corporation ("IFC") hereby notifies G.W. Servicios,
S.A. de C.V. (the "Borrower") that the conditions of effectiveness described in
Section 5.01 of the Amended and Restated Loan Agreement dated as of March 15,
2005, among the Borrower, Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V.
and IFC (the "Loan Agreement") have been met. Consequently, the Loan Agreement
and the other documents described in Section 5.01(a) of the Loan Agreement shall
be effective as of the date thereof (subject, in the case of any document to
which Nederlandse Financierings-Maatschappij voor Ontwikkelingslanden N.V.
("FMO") is a party, to receipt by the Borrower and IFC of a comparable notice of
effectiveness from FMO).

                                                Yours truly,

                                                INTERNATIONAL FINANCE CORPORATIN

                                                By ________________________

cc: FMO

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 75 -

                                                                      SCHEDULE 4
                                                                     Page 1 of 2

                       FORM OF SERVICE OF PROCESS LETTER
                  [Letterhead of Agent for Service of Process]
                  (See Section 8.05 (c) of the Loan Agreement)

                                                                          [Date]

International Finance Corporation
2121 Pennsylvania Avenue, N.W.
Washington, D.C.  20433

Attention: Director, Infrastructure Department

Dear Sirs:

      Reference is made to Section 8.05 of the Loan Agreement dated December 5,
2000, as amended and restated as of March 15, 2005 (the "Loan Agreement"), among
GW Servicios, S.A. de C.V. (the "Borrower"), Compania de Ferrocarriles
Chiapas-Mayab, S.A. de C.V. (the "Project Company") and International Finance
Corporation ("IFC"). Unless otherwise defined herein, capitalized terms used
herein shall have the meaning specified in the Loan Agreement.

      Pursuant to Section 8.05 (c) of the Loan Agreement, each of the Borrower
and the Project Company has irrevocably designated and appointed the
undersigned, CT Corporation System, with offices currently located at 111 Eighth
Avenue, 13th Floor, New York, New York 10011, as its authorized agent to receive
for and on its behalf service of process in any legal action or proceeding with
respect to the Loan Agreement in the courts of the United States of America for
the Southern District of New York.

      The undersigned hereby informs you that it has irrevocably accepted that
appointment as process agent as set forth in Section 8.05(c) of the Loan
Agreement from _______(2) until ___________ (3) and agrees with you that the
undersigned (i) shall inform IFC and FMO promptly in writing of any change of
its address in New York, (ii) shall perform its obligations as such process
agent in accordance with the relevant provisions of Section 8.05(c) of the Loan
Agreement, and (iii) shall forward promptly to the Borrower and the Project
Company any legal process received by the undersigned in its capacity as process
agent.

---------------------
(2)   Insert date of effectiveness of appointment.

(3)   Insert date which is [three] months after the last repayment of the Loan.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 76 -

                                                                      SCHEDULE 4
                                                                     Page 2 of 2

      As process agent, the undersigned and its successor or successors agree to
discharge the above-mentioned obligations and will not refuse fulfillment of
such obligations as provided under Section 8.05 (c) of the Loan Agreement.

                                                         Very truly yours,

                                                         CT Corporation System

                                                         By____________________
                                                            Title:

cc: [Borrower]
    [Project Company]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 77 -

                                                                      SCHEDULE 5
                                                                     Page 1 of 1

                                   [reserved]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 78 -

                                                                      SCHEDULE 6
                                                                     Page 1 of 2

                      FORM OF LETTER TO BORROWER'S AUDITORS

                             (See Section 6.01(e) of
                               the Loan Agreement)

                             [Borrower's Letterhead]

                                                                          [Date]

[NAME OF AUDITORS]
[ADDRESS]

Ladies and Gentlemen:

      We hereby authorize and request you to give to International Finance
Corporation of 2121 Pennsylvania Avenue, N.W., Washington, D.C. 20433, United
States of America ("IFC"), all such information as IFC may reasonably request
with regard to the financial statements of the undersigned company, both audited
and unaudited. We have agreed to supply that information and those statements
under the terms of an Loan Agreement between the undersigned company, Compania
de Ferrocarriles Chiapas-Mayab, S.A. de C.V., and IFC dated December 5, 2000, as
amended and restated as of March 15, 2005 (the "Loan Agreement"). For your
information we enclose a copy of the Loan Agreement.

      We authorize and request you to send two copies of the audited accounts of
the undersigned company to IFC to enable us to satisfy our obligation to IFC
under Section 6.04(b)(i) of the Loan Agreement. When submitting the same to IFC,
please also send, at the same time, a copy of your full report on such accounts
in a form reasonably acceptable to IFC.

      Please note that under Section 6.04(b)(ii) and (iii) and Section 6.04(c)
of the Loan Agreement, we are obliged to provide IFC with:

      (a) a copy of the annual and any other management letter or other
communication from you to the undersigned company or its management commenting
on, among other things, the adequacy of the undersigned company's financial
control procedures and accounting and management information system; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 79 -

                                                                      SCHEDULE 6
                                                                     Page 2 of 2

      (b) a report by you certifying that, based upon its audited financial
statements, the undersigned company and the Project Company (as defined in the
Loan Agreement) were in compliance with the financial covenants contained in
Section 6.02 and Section 6.03, respectively, of the Loan Agreement as at the end
of the relevant Financial Year or, as the case may be, detailing any
non-compliance.

      Please also submit each such communication and report to IFC with the
audited accounts.

      For our records, please ensure that you send to us a copy of every letter
which you receive from IFC, immediately upon receipt and a copy of each reply
made by you immediately upon the issue of that reply.

                                                 Yours truly,

                                                 GW SERVICIOS, S.A. DE C.V.

                                                 By ________________________
                                                     Authorized Representative

Enclosure

cc: Director
    Infrastructure Department
    International Finance Corporation
    2121 Pennsylvania Avenue, N.W.
    Washington, D.C. 20433
    United States of America

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 80 -

                                                                      SCHEDULE 7
                                                                     Page 1 of 2

          FORM OF BORROWER'S CERTIFICATION ON DISTRIBUTION OF DIVIDENDS

                   (See Section 6.02(a) of the Loan Agreement)

                             [Borrower's Letterhead]

International Finance Corporation                                         [Date]
2121 Pennsylvania Avenue, N.W.
Washington, D.C. 20433

Attention: Director, Infrastructure Department

Dear Sirs:

1. Please refer to the Loan Agreement (the "Loan Agreement") dated December 5,
2000, as amended and restated as of March 15, 2005, among GW Servicios, S.A. de
C.V. (the "Borrower"), Compania de Ferrocarriles Chiapas-Mayab, S.A. de C.V.
(the "Project Company") and International Finance Corporation ("IFC"). Terms
defined in the Loan Agreement have their defined meanings whenever used in this
request.

2. This is to inform you that the Borrower plans a distribution of dividends to
its shareholders in the aggregate amount of ______________ (______), such
distribution to commence on or about _________, ___. Pursuant to Section 6.02(a)
of the Loan Agreement, the Borrower hereby certifies that, as at the date
hereof:

      (a)   the proposed distribution will be entirely out of retained earnings
            and such retained earnings do not include any amount resulting from
            the revaluation of any of the Borrower's assets;

      (b)   no Event of Default or Potential Event of Default has occurred and
            is continuing;

      (c)   prior to the date hereof, the Borrower has made prepayments under
            Section 3.07 of the Loan Agreement in a sufficient amount, and such
            prepayments have been applied against the remaining installments of
            the A Loan and B Loan in inverse order of maturity (as required
            under Section 3.07(c) of the Loan Agreement), such that (i) the
            final installment of the A Loan under Section 3.06 of the Loan
            Agreement is due no later than September 15, 2009 and (ii) the final
            installment of the B Loan under Section 3.06 of the Loan Agreement
            is due no later than September 15, 2008; and

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 81 -

                                                                      SCHEDULE 7
                                                                     Page 2 of 2

      (d)   after giving effect to the proposed distribution:

            (i)   the Borrower's Current Ratio would be at least 1.0;

            (ii)  the Borrower's Long-term Debt to Tangible Net Worth Ratio
                  would be less than 2.0; and

            (iii) the Borrower's Debt Service Coverage Ratio would not be less
                  than 1.4.

3. The Borrower undertakes not give effect to the proposed distribution or any
part thereof if, at the time of so doing or after giving effect to it, the
Borrower could not certify the matters referred to in section 2 of this
certification.

                                                            Yours truly,

                                                  GW SERVICIOS, S.A. DE C.V.

                                                  By ________________________
                                                      Authorized Representative

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 82 -

                                                                      SCHEDULE 8
                                                                     Page 1 of 1

                                   [reserved]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 83 -

                                                                      SCHEDULE 9
                                                                     Page 1 of 2

            INFORMATION TO BE INCLUDED IN ANNUAL REVIEW OF OPERATIONS

                (See Section 6.04(b) (iv) of the Loan Agreement)

      [(1)  Sponsors and Shareholdings. Information on significant changes in
            share ownership of Borrower, the reasons for such changes, and the
            identity of major new shareholders.

      (2)   Country Conditions and Government Policy. Report on any material
            changes in local conditions, including government policy changes,
            that directly affect the Borrower (e.g. changes in government
            economic strategy, taxation, foreign exchange availability, price
            controls, and other areas of regulations.)

      (3)   Management and Technology. Information on significant changes in (i)
            the Borrower's senior management or organizational structure, and
            (ii) technology used by the Borrower, including technical assistance
            arrangements.

      (4)   Corporate Strategy. Description of any changes to the Borrower's
            corporate or operational strategy, including changes in products,
            degree of integration, and business emphasis.

      (5)   Markets. Brief analysis of changes in Borrower's market conditions
            (both domestic and export), with emphasis on changes in market share
            and degree of competition.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 84 -

                                                                      SCHEDULE 9
                                                                     Page 2 of 2

      (6)   Operating Performance. Discussion of major factors affecting the
            year's financial results (sales by value and volume, operating and
            financial costs, profit margins, capacity utilization, capital
            expenditure, etc.).

      (7)   Financial Condition. Key financial ratios for previous year,
            compared with ratios covenanted in the Loan Agreement.]

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 85 -

                                                                     SCHEDULE 10
                                                                     Page 1 of 4

                        FORM OF ANNUAL MONITORING REPORT

                  (See Section 6.04 (d) of the Loan Agreement)

GENERAL INSTRUCTIONS: provide information in sufficient detail for evaluation of
environmental performance in relation to:

-  National and local laws and regulations in Mexico;

   -  World Bank/IFC environmental and social policies and guidelines:

      -  IFC Environmental, Health and Safety Guidelines for Railroad Systems,
         November 20, 1995;

      -  IFC Policy on Environmental Assessment (OP 4.01), October 1998;

      -  IFC Policy on Pest Management (OP 4.09), November 1998;

      -  World Bank Policy on Involuntary Resettlement (OD 4.30), June 1990;

      -  World Bank Policy Note on Management of Cultural Property (OPN 11.03),
         September 1986; and

      -  IFC Policy Statement on Forced Labor and Harmful Child Labor, March
         1998.

-  Loan Agreement, (DATE);

-  Environmental Review Summary, February 8, 2000;

-  Herbicide Management Plan (Criterio Para El Uso De Herbicidas En La: Compania
   De Ferrocarriles Chiapas-Mayab, S. A. de C. V.), May 25, 2000;

-  Environmental Corrective Action Plan, Compania De Ferrocarriles
   Chiapas-Mayab, August 4, 2000;

Provide information in summary form and enclose environmental reports if
applicable. For any areas that do not meet agreed-upon performance levels,
describe actions and timetable for bringing the project into compliance.

Information reported previously need only be referenced.

Return the completed report to IFC by the date specified in the Loan Agreement
(April 1).

Please note that the term "environment" includes workplace and community health
and safety as well as social and cultural issues.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 86 -

                                                                     SCHEDULE 10
                                                                     Page 2 of 4

PROJECT INFORMATION
Contact Person:
Telephone:
Fax:
E-mail:

Report period: from _______________ to ______________

SUMMARY OF CURRENT OPERATIONS - Describe company operations, level of business
activity, etc.

STATUS OF MODERNIZATION/EXPANSION OR NEW PROJECT IMPLEMENTATION - Provide a
description, status, and completion timetable for all environment-related items
in any modernization/ expansions or new projects.

CHANGES TO COMPANY - Describe significant changes in the company, such as
changes in capacity, product lines, business activities, customers served, or
acquisitions that may affect environmental performance.

CHANGES IN OPERATIONS - Describe any changes in day-to day operations, such as
use of different cleaning solvents or thinners, any changes in chemicals used or
storage methods, changes in solid/hazardous waste disposal, use of difference
service providers.

COMPLIANCE WITH ENVIRONMENTAL REQUIREMENTS - Is the company currently in
compliance with national and local laws and regulations and applicable World
Bank guidelines? (If no, please explain.)

ENVIRONMENTAL ISSUES - Highlight any new or emerging environmental issues, such
as pending regulations. Describe any changes affecting the environmental impacts
of the company's operations.

NEW INITIATIVES AIMED AT IMPROVING ENVIRONMENTAL PERFORMANCE - Describe any
planned initiatives. Examples are implementation of a formal environmental
management system (EMS), recycling initiatives, waste minimization and energy
efficiency measures.

                             CORRECTIVE ACTION PLAN

Provide a status report on each item in the CAP, including any difficulties
encountered or revised completion dates.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 87 -

                                                                     SCHEDULE 10
                                                                     Page 3 of 4

HERBICIDE MANAGEMENT PLAN

Provide an update on the company's vegetation control system, including
procedures used (e.g., mechanical, chemical), herbicides used, changes in the
program.

WOOD CROSSTIE SOURCING

Provide a summary of crosstie purchases, including supplier, number of ties,
wood source.

Provide confirmation that FCCM has purchased crossties only from suppliers
approved by the Mexican government.

RELOCATION OF BUSINESSES OR PEOPLE

Provide a summary of right-of-way management activities, including encroachment
incidents. If new encroachments have occurred, explain how they were addressed
in compliance with Government of Mexico requirements. (Except for new
encroachments, any relocation of businesses or people residing on the
right-of-way must be conducted with the prior notification of IFC and in
accordance with World Bank policy 4.30 on Involuntary Resettlement.)

UNAUTHORIZED USE OF COMPANY FACILITIES

Provide an update of FCCM's programs to curb use of company facilities by
illegal immigrants.

COMPLIANCE TESTING

                                  AIR EMISSIONS

Provide summary of any testing by local authorities.

Provide summary of any testing by the company, including ambient air quality and
fugitive dust monitoring (include maps, figures, etc. as necessary for IFC's
review).

            LIQUID EFFLUENTS (INCLUDING SANITARY AND STORM EFFLUENTS)

Describe day-to-day operations of effluent handling and treatment facilities,
difficulties encountered, remedies, etc.

Provide summary of any testing by local authorities.

Provide summary of any testing by the company, including process effluent, storm
water, and sewage (include maps, figures, etc. as necessary for IFC's review).

                                      NOISE

Provide summary of any testing by local authorities.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 88 -

                                                                     SCHEDULE 10
                                                                     Page 4 of 4

Provide summary of any testing by the company, including noise levels
experienced by outside receptors and occupational noise (include maps, figures,
etc. as necessary for IFC's review).

                     ACCIDENTS, FIRES, AND OTHER EMERGENCIES

Provide a summary of any accidents, derailments, fires, or explosions, or
significant accidental releases to the environment. Include response measures
taken and any improvements made to equipment or procedures as a result.

                      WORKER HEALTH AND OCCUPATIONAL SAFETY

Provide a summary of work-related accidents, discussion of trends, response
measures taken, and other actions taken to reduce accidents.

Provide a summary of training activities, including any new programs that have
been implemented.

Describe status of implementation of equipment safeguarding and provision of
personal protective equipment (PPE). Evaluate usage rate of PPE and identify any
needed improvements.

                               COMMUNITY RELATIONS

Describe any outreach or cooperative programs with the community.

Report any significant accidental releases, failure to meet permit limits,
lawsuits, community complaints, adverse media coverage, etc.

                       Amended and Restated Loan Agreement

<PAGE>

                                     - 89 -

                                                                     SCHEDULE 11
                                                                     Page 1 of 1

                                  FORM OF NOTES

                    (See Section 3.17 of the Loan Agreement)

                                   [Reserved]

                       Amended and Restated Loan Agreement