Exhibit 10.4

--------
        MEXICAN MINISTRY OF
SCT     COMMUNICATIONS AND
--------TRANSPORTATION
UNDER MINISTRY OF COMMUNICATIONS










                       CONCESSION CERTIFICATE FOR A PUBLIC
                    TELECOMMUNICATIONS NETWORK FOR PROVISION
                 SERVICE IN REGIONS 1, 2, 3, 4, 5, 6, 7, 8 AND 9









                  Telefonia Inalambrica del Norte, S.A. de C.V.


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[A seal with the Mexican coat-of-arms reading:]
"United Mexican States - Ministry of
Communications and Transportation"

Concession to install, operate and exploit a public telecommunications network
that is granted by the Mexican Federal Government through the Mexican Ministry
of Communications and Transportation (the "Ministry"), to Telefonia Inalambrica
del Norte, S.A. de C.V. (the "Concession Holder") a company with registered
address at Idaho No. 14, Col. Napoles, 03810 Mexico, D.F.

                                   WITNESSETH

I. WHEREAS, on October 18, 1997, the Concession Holder applied for the approval
of the Federal Telecommunications Commission (the "Commission") to participate
in a tender of bids with a view to obtain a concession to use, operate and
exploit frequency bands of the radioelectric spectrum and provide
point-multipoint microwave linking services, pursuant to the Invitation to
Tender Bids that was published in the Federal Official Gazette on April 30, 1997
(the "Tender"), and the Tender Rules that were published in the Federal Official
Gazette on May 14, 1997, and the amendments thereto that were also published in
the Federal Official Gazette on June 10, 1997 (the "Tender Rules"). Said
application was also filed with a view to obtain a concession to install,
operate and exploit a public telecommunications network, pursuant to the
provisions of articles 18, last paragraph and 24 of the Federal
Telecommunications Law.

II. WHEREAS, at its session held on July 10, 1997, the Federal Competition
Commission en banc resolved not to express any objection or submit the
Concession Holder's participation in the Tender to any condition. This
resolution was notified to the Concession Holder under official communication
#3-101-(777)-97-274 dated July 10, 1997.

III. WHEREAS, the Ministry, through the Commission, analyzed all documents
submitted by the Concession Holder and, according to the different stages of the
bidding process described in the Tender and in articles 14, 15, 16, 17 et al of
the Mexican Federal Telecommunications Law, resolved to grant the Concession
Holder a Certificate of Qualification, due to the fact that the documents were
complete and met all necessary requirements. This resolution was informed to the
Concession Holder under official communication # CFT-209 dated July 14, 1997.

IV. WHEREAS, the Commission, under official communication #CFT-246 dated July
23, 1997, resolved to grant a Certificate of Participation to the Concession
Holder, considering that on July 17, 1997 the Concession Holder had submitted
the pertinent bid bond, and assigned to the Concession Holder a confidentiality
code to participate in the bidding process. Considering further that the
Concession Holder submitted the highest valid bid, the Commission en banc, under
resolution dated October 3, 1997, declared the Concession Holder as the
successful bidder in competitive biddings 36PAM10-1, 37PAM10-2, 38PAM10-3,
39PAM10-4, 40PAM10-5, 41PAM10-6, 42PAM10-7, 43PAM10-8 Y 44PAM10-9 of said
Tender, according to the Tender Rules.

V. WHEREAS, the Ministry, through the Commission, analyzed all documents related
to the application filed by the Concession Holder and resolved that such
documents satisfied all requirements of the Mexican Federal Telecommunications
Law and all other applicable regulations. Therefore, pursuant to the provisions
of articles 36(III) of the Mexican Organic Law of the Federal Public
Administration; 11(II), 12, 18, 24, 25, 26, 27 and all other related articles of
the Mexican Federal Telecommunications Law, the Ministry hereby grants the
Concession Holder this concession to install, operate and exploit a public
telecommunications network, subject to the following:


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                                   CONDITIONS

                                  First Chapter
                               General Provisions

1.1 Definitions. In addition to the definitions contained in the Mexican Federal
Telecommunications Law, when used herein the following terms shall have the
following meanings:

     1.1.1 Commission, shall mean the Federal Telecommunications Commission;

     1.1.2 Concession, shall mean the concession that is granted under this
Certificate for the installation, operation and exploitation of a public
telecommunications network;

     1.1.3 Law, shall mean the Mexican Federal Telecommunications Law; and

     1.1.4 Network, shall mean the public telecommunications network that is the
subject matter of concession;

1.2 Services. The Concession Holder agrees to install, operate and exploit the
Network and provide all services referred to in the exhibit(s) to this
Certificate in accordance with all terms and conditions set forth therein.
Likewise, the Concession Holder agrees to submit for approval by the Commission,
prior to their instrumentation, all agreements to be executed with the users for
provision of the services referred to in the exhibit(s) to the Concession,
pursuant to all applicable legal, regulatory and administrative provisions.

The Concession Holder may provide services additional to those covered by the
exhibit(s) to the Concession, subject to the approval of the Ministry. To this
end, the Concession Holder shall file an application that is satisfactory for
the Ministry and meets all requirements of article 24 of the Law and all other
applicable provisions, without prejudice of the fact that, in case any
concession for frequency bands of the radioelectric spectrum is required, such
concession shall be granted through the public bidding process contemplated by
article 14 and all other applicable articles of the Law.

The approval or concession mentioned in the immediately preceding paragraph
shall be granted only if the Concession Holder is in compliance with all of its
obligations related to the Concession.

According to article 33 of the Law, the Concession Holder may provide value
added services, subject to the prior registration of the services with the
Commission.

1.3 Modification of the Coverage. The Concession Holder will be able to modify
the geographic coverage of the Network, subject to the prior approval of the
Commission, except in case of modification of the coverage as regards bands of
the radioelectric spectrum, in which event the prior approval of the Ministry
shall be required.

The Commission or the Ministry shall, as the case may be, approve or disapprove
the application for modification of the coverage within one hundred and twenty
(120) calendar days following receipt of the application, provided that the
Concession Holder is fully complying with all of its obligations related to the
Concession.


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                                       3


1.4 Effective term. The term of this Concession shall be of twenty (20) years
from the date hereof. The term of the Concession may be extended, pursuant to
the provisions of article 27 of the Law.

1.5 Applicable laws. The Network and the services subject matter of this
Concession shall be installed, operated and exploited and provided,
respectively, pursuant to the provisions of the Political Constitution of the
United Mexican States, the Law and any supplementary laws set forth in article 8
of the Law, and any international treaties, laws, regulations, decrees, Rules,
master technical plans, Mexican official standards, rulings, orders, circular
letters and all other legal, regulatory and administrative provisions that may
be introduced by the Ministry or the Commission, and pursuant to all conditions
set forth herein.

The Concession Holder agrees that in case of derogation or amendment of or
additions to the legal, regulatory or administrative provisions referred to in
the first paragraph of this clause 1.7 to which this Concession is subject, the
Concession Holder shall be subject to all successor laws and administrative
provisions, from the effective date thereof.

1.6 Other Concessions. This Concession does not grant any exclusivity rights to
the Concession Holder, but the Ministry may, within the same geographic area,
grant other concessions to third parties for the installation, operation and
exploitation of one or more public telecommunication networks, for provision of
services identical or similar to the services covered by this Concession.

1.7 Assignment of Rights. The Concession Holder may assign all or any of its
rights and obligations under the Concession, pursuant to the provisions of
article 35 of the Law and all other applicable provisions.

1.8 Provision of Services through Affiliates or Subsidiaries. The Concession
Holder may, subject to the prior approval of the Ministry, provide any services
covered by this Concession through any affiliate or subsidiary, provided the
Concession Holder will prove, to the satisfaction of the Ministry, that the
affiliate or subsidiary has all financial capacity required for provision of the
services subject matter of the Concession. Notwithstanding the foregoing, the
Concession Holder shall always be responsible to the Ministry for the
performance of all obligations related to the Concession.

1.9 Powers of Attorney. The Concession Holder in no event shall grant any
irrevocable general power of attorney for acts of administration or acts of
ownership that is intended to empower or entitle the attorney-in-fact or grantee
to exercise any right or perform any obligation under the Concession.

1.10 Liens. In case any lien is created on the Concession or on any rights
thereunder by the Concession Holder, the lien shall be recorded as required by
article 64 of the Law, within thirty (30) calendar days following the date of
creation of the lien.

The instrument under which the created lien was documented shall expressly
provide that the creditor in no event shall acquire the capacity of Concession
Holder in case of foreclosure of the lien.

The Concession may only be assigned to a creditor or a third party if the
assignment of all rights arising therefrom is approved by the Ministry, pursuant
to the provisions of article 35 of the Law, or if a concession is granted
pursuant to the provisions of article 24 of the Law, provided that in this
latter event the frequency bands of the radioelectric spectrum shall not be
included in the concession.


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                                       4


1.11 Nationality. The Concession Holder shall, with respect to this Concession,
not have any rights other than the rights available at Mexican nationals under
the Mexican laws. Consequently, the Concession Holder and its non-Mexican
shareholders or members, if any, agree not to request or accept the diplomatic
involvement of any foreign government, under the penalty, in case of breaching
this provision, of forfeiting to the Mexican government all property and rights
that the shareholders or members may have acquired for the installation,
operation and exploitation of the Network.

1.12 Neutral Investment. Pursuant to the provisions of the Fifth Title of the
Mexican Foreign Investment Law, neutral investment shall not be taken into
consideration to determine the percentage of the interest held by foreign
investors in the Concession Holder's capital stock.

1.13 Companies where a Foreign Government Holds an Interest in their Capital
Stock. Any interest held by a company where a foreign government may have an
interest in its capital stock shall not be considered as an interest held by a
foreign government or State, provided the company is not considered as a
government authority by the internal laws of its country of origin and has legal
capacity and assets of its own.

1.14 Subscription and Transfer of Shares of Stock or Partnership Interests. The
Concession Holder shall provide to the Ministry and the Commission, no later
than April 30 of each year, a list showing the names of its 10 main shareholders
and the percentages represented by their respective interests in the Concession
Holder's capital stock, attaching thereto all information that may be required
by the Commission.

In case of any attempt to subscribe or transfer shares of stock or partnership
interests, either in one transaction or a series of related transactions, that
represent 10% or more of the Concession Holder's capital stock, the procedure
below shall be followed:

     1.14.1 The Concession Holder shall give the Ministry notice of the
intention of any parties interested in subscribing or transferring shares of
stock or partnership interests of the Concession Holder's capital stock,
attaching thereto information on the potential buyers of the shares of stock or
partnership interests;

     1.14.2 The Ministry shall be entitled to disapprove the transaction in
question within ninety (90) calendar days following receipt of the notice, by
giving written notice of its disapproval and providing all reasons therefor; and

     1.14.3 If not disapproved by the Ministry upon expiration of the
above-mentioned 90-day term, the transaction shall be deemed approved.

Only those transactions that shall have not been disapproved by the Ministry may
be recorded in the stock transfer book of the Concession Holder, regardless of
any other approvals that must be obtained from other government authorities
pursuant to the applicable legal, regulatory and administrative provisions. The
notice referred to in clause 1.14.1 above shall not be required when the
subscription or transfer involves shares of stock or partnership interests
representing neutral investment pursuant to the terms of the Mexican Foreign
Investment Law, or when a capital increase is subscribed by the same
shareholders, provided that in this latter event each shareholder maintains the
same percentage of interest in the corporation's capital stock.


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                                       5


If the party interested in subscribing or acquiring the shares of stock or
partnership interests is a corporation, then the notice referred to in clause
1.14.1 above shall include all information needed for the Ministry to know the
identity of all individuals having an interest above 10% in the corporation's
capital stock.

This condition shall be included in the bylaws of the Concession Holder and in
all share certificates issued by it.

1.15 Training and Technological Development. The Concession Holder shall develop
training programs for its employees, and shall also conduct research and
development activities in Mexico.

1.16 Designation of Person Responsible for Technical Issues. The Concession
Holder shall designate a person who shall be responsible to the Commission for
the technical operation of the Network. Said person shall have all powers of
administration that may be needed to assume obligations to the Commission on
behalf of the Concession Holder with respect to the technical operation of the
Network.

                                 Second Chapter
                      Provisions Applicable to the Services

2.1 Quality of the Services. The Concession Holder shall provide all services
covered by this Concession in an efficient and uninterrupted fashion, according
to the applicable laws, the technical characteristics set forth in the
exhibit(s) to this Concession, and all applicable administrative provisions.

Further, the Concession Holder shall instrument all mechanisms that may be
needed to repair the Network or any service failure within eight (8) business
hours following receipt of the failure report.

The Concession Holder shall ensure that all services covered by this Concession
be provided under the best pricing, diversity and quality conditions to the
benefit of all users, so as to promote the efficient development of
telecommunications. To this end, the Concession Holder shall submit to the
Commission, within one hundred and twenty (120) calendar days following the date
hereof, the minimum quality standards for the services, regardless of the
Commission's right to issue general application rules to that effect.

2.2 Interruption of the Services. If the provision of any service is interrupted
for more than seventy two (72) consecutive hours following the time set forth in
the pertinent report, the Concession Holder shall credit to the users that
portion of the rate corresponding to the duration of the interruption.

2.3 Service and Repair Calls. The Concession Holder shall instrument a system to
receive service and repair calls.

The Concession Holder shall prepare a monthly report on the occurrence of
failures per type of failure, all corrective actions adopted and all credits
made to the users, for submission to the Commission upon request.

The Commission may make the above information available to the public, jointly
with information from any other concessionaires that provide similar services in
Mexico or in the same region.

2.4 Measurement and Quality Control Equipment. The Concession Holder shall take
all actions needed to ensure the accuracy and reliability of all equipment used
to measure the quality of and bill the services. To this end, the


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                                       6


Concession Holder shall make calibration tests to its equipment and provide to
the Commission on a quarterly basis, upon request, the results of the tests and
all documents proving that the pertinent adjustments, if any, have been made.

Further, the Concession Holder shall keep all resulting information in such
records for the measurement equipment as may be determined by the Commission.

2.5 Trade Practices Code. The Concession Holder shall, pursuant to any general
application rules that may be issued by the Commission therefor, develop a trade
practices code to clearly and briefly describe therein all services to be
provided by it and the method to be used for application of the pertinent rates.
The Concession Holder shall, after development of the code and subject to the
Commission's prior approval, make an excerpt of the code available to the public
at its commercial offices and publish the excerpt in one of the newspapers
having wide circulation throughout Mexico.

2.6 Emergency Services. The Concession Holder shall, on the date of commencement
of the operation and exploitation of the Network, make available to the
Commission an action plan to prevent the interruption of the services and to
provide emergency services in case of occurrence of an act of God or force
majeure.

In case of occurrence of an emergency situation within the area covered by the
Concession Holder, the Concession Holder shall provide, free of charge, all
basic services ordered by the Ministry, only for the period of time and to the
extent required by the emergency situation.

The Concession Holder shall inform the Commission of any event that may have a
general and material impact on the operation of the Network.

                                  Third Chapter
                                      Rates

3.1 Improper Charging of Rates. Should the Concession Holder charge its users
any rates other than its registered rates or the rates, if any, established
pursuant to the provisions of articles 61 and 63 of the Law, then the Concession
Holder shall reimburse its users the amount charged in excess of the registered
or established rates.

The above reimbursement will be made without prejudice of any penalties that may
be imposed on the Concession Holder pursuant to the Law and all other applicable
legal, regulatory and administrative provisions.

3.2 No Crossed Subsidies. The Commission shall be entitled to ensure at any time
that the registered rates do not constitute crossed subsidies pursuant to the
provisions of article 62 of the Law, for which purpose the Concession Holder
shall provide all pertinent information within sixty calendar days following the
date of receipt of the Commission's request.

3.3 Billing. All billing systems of the Concession Holder are subject to the
approval of the Commission before their instrumentation.


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                                 Fourth Chapter
                          Confirmation and Information

4.1 Without prejudice of the Commission's power to request the Concession Holder
to provide any other information, pursuant to the terms of article 68 of the
Law, the Concession Holder shall provide the following to the Commission within
one hundred and fifty (150) calendar days following the closing of each fiscal
year of the Concession Holder:

     4.1.1 Audited financial statements, itemized per service and, if pertinent,
per geographic area;

     4.1.2 A description of the main fixed assets of the Concession Holder that
form the Network, according to the forms established by the Commission therefor;
and

     4.1.3 A report on all actions taken with respect to the training programs
for the Concession Holder's employees, and on all research and development
activities conducted in Mexico, as set forth in clause 1.15 of this Concession.

4.2 The Concession Holder shall submit quarterly reports to the Commission on
the progress of the expansion program for the Network.

4.3 The Concession Holder shall submit to the Commission, upon request,
statistical information on traffic, routing, occupation, performance and other
operating parameters of the Network, in accordance with the general provisions
that may be issued by the Commission therefor. Further, the Concession Holder
shall provide accounting information per service, region, function and component
of the Network, subject to the prior approval by the Commission of the pertinent
methods and dates therefor.

                                  Fifth Chapter
                                Performance Bonds

6. The Concession Holder shall place, to the satisfaction of the Ministry, all
bonds that may be required to guarantee the performance of the Concession
Holder's obligations under this Concession, in the form and terms set forth in
the Exhibit(s) to the Concession.

                                  Sixth Chapter
                                Competent Courts

7. Competent courts. For resolution of any matter related to the interpretation
and enforcement of this Concession Certificate, other than any issue reserved
for resolution by the Ministry or the Commission under an administrative
resolution, the Concession Holder agrees to submit to the jurisdiction of the
federal courts of Mexico City, Mexico, waiving any other jurisdiction that might
correspond to it by reason of its present or future domicile.

                       Mexico City, Mexico, April 1, 1998.

                THE MINISTRY OF COMMUNICATIONS AND TRANSPORTATION

                                  By: [signed]

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                                       8


                              CARLOS RUIZ SACRISTAN
                                    MINISTER


                              THE CONCESSION HOLDER
                  TELEFONIA INALAMBRICA DEL NORTE, S.A. DE C.V.

                                  By: [signed]
                               TOMAS MILMO SANTOS
                              LEGAL REPRESENTATIVE




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[COMPANY LOGO]




















                               TITULO DE CONCESION
                      DE RED PUBLICA DE TELECOMUNICACIONES
                     PARA LAS REGIONES 1,2,3,4,5,6,7,8 Y 9.

















                  Telefonia Inalambrica del Norte, S.A. de C.V.




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    SECRETARIA DE COMUNICACIONES
                  Y
             TRANSPORTES



Concesion para instalar, operar y explotar una red publica de
telecomunicaciones, que otorga el Gobierno Federal por conducto de la Secretaria
de Comunicaciones y Transportes, en lo sucesivo la Secretaria, en favor de
Telefonia Inalambrica del Norte, S.A. de C.V., en lo sucesivo el Concesionario,
con domicilio para oir y recibir notificaciones en Idaho No. 14, Col. Napoles,
03810 Mexico, D.F., al tenor de los siguientes antecedentes y condiciones.

                                  ANTECEDENTES

I.   El Concesionario presento solicitud ante la Comision Federal de
     Telecomunicaciones, en lo sucesivo la Comision, con fecha 18 de junio de
     1997, para participar en la licitacion para el otorgamiento de concesiones
     para el uso, aprovechamiento y explotacion de bandas de frecuencias del
     espectro radio-electrico para la prestacion del servicio de provision de
     enlaces de microondas punto a multipunto de conformidad con la Convocatoria
     publicada en el Diario Oficial de la Federacion el dia 30 de abril de 1997,
     en lo sucesivo la Convocatoria, asi como de las bases de licitacion
     respectivas, publicadas en el Diario Oficial de la Federacion el dia 14 de
     mayo de 1997 y sus modiflicaciones publicadas en el Diario Oficial de la
     Federacion el dia 10 de junio de 1997 en lo sucesivo las Bases. Dicha
     solicitud se presento tambien con efectos de obtener una concesion para
     instalar, operar y explotar una red publica de telecomunicaciones, de
     conformidad con lo establecido por los articulos 18, ultimo parrafo y 24 de
     la Ley Federal de Telecomunicaciones.

II.      El Pleno de la Comision Federal de Competencia resolvio en sesion
         celebrada el 10 de julio de 1997, no objetar ni condicionar la
         participacion del Concesionario en la licitacion anteriormente
         senalada, siendo notificado el Concesionario con Oficio numero
         3-101-(777)-97-274 de fecha 10 de julio de 1997.

III.     La Secretaria, por conducto de la Comision, analizo y dictamino la
         documentacion de la solicitud del Concesionario y de acuerdo a las
         etapas del procedimiento de licitacion previsto en la Convocatoria y en
         los articulos 14, 15, 16, 17 y demas relativos de la Ley Federal de
         Telecomunicaciones, resoivio mediante oficio No. CFT.-209 de fecha 14
         de julio de 1997, otorgar al Concesionario la Constancia de
         Calificacion por estar debidamente integrada y haber satisfecho los
         requisitos para tal efecto exigidos.

IV.      La Comision con Oficio No. CFT.-246 de fecha 23 de julio de 1997,
         resolvio otorgar la Constancia de Participacion al Concesionario, en
         virtud de que con fecha 17 de julio de 1997, presento la Garantia de
         Seriedad correspondiente, proporcionandole en el mismo acto la clave de
         confidencialidad para participar en el proceso de licitacion. El Pleno
         de la Comision emitio fallo a favor del Concesionario, mediante acta
         fechada el 3 de octubre de 1997, adjudicandole los concursos 36PAM10-1,
         37PAM10-2, 38PAM10-3, 39PAM10-4, 40PAM10-5, 41PAM10-6, 42PAM10-7,
         43PAM10-8 y 44PAM10-9, de conformidad con las Bases.

V.       La Secretaria, a traves de la Comision, analizo y evaluo la
         documentacion correspondiente a la solicitud del Concesionario,
         resolviendo que la misma cumplio a satisfaccion con los requisitos
         exigidos por la Ley Federal de Telecomunicaciones y demas disposiciones
         aplicables. Por lo que, con fundamento en los articulos 36, fraccion
         III de la Ley Organica de la Administracion Publica Federal; 11,
         fraccion II, 12, 18, 24, 25, 26, 27 y demas relativos de la Ley Federal
         de Telecomunicaciones, la Secretaria otorga al Concesionario la
         presente concesion para instalar, operar y explotar una red publica de
         telecomunicaciones, la que quedara sujeta a las siguientes.



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                                   CONDICIONES

                                Capitulo Primero
                             Disposiciones Generales

1.1.     Definicion de terminos. En adicion a las definiciones contenidas en la
         Ley Federal de Telecomunicaciones, para los efectos de la presente
         concesion se entendera por:

1.1.1.   Comision: la Comision Federal de Telecomunicaciones;

1.1.2.   Concesion: la contenida en el presente Titulo para instalar, operar y
         explotar una red publica de telecomunicaciones;

1.1.3.   Ley: la Ley Federal de Telecomunicaciones, y

1.1.4.   Red: la red publica de telecomunicaciones objeto de la Concesion.

1.2.     Servicios. El Concesionario se obliga a instalar, operar y explotar la
         Red y a prestar los servicios a que se refieren los anexos de la
         Concesion, en los terminos y condiciones ahi indicados. De igual forma,
         el Concesionario se obliga a someter a la aprobacion de la Comision,
         previo a su aplicacion, los contratos tipo a ser celebrados con los
         usuarios, con relacion a la prestacion de los servicios a que se
         refieren los anexos de la Concesion, de conformidad con las
         disposiciones legates, reglamentarias y administrativas aplicables.

         El Concesionario podra prestar servicios adicionales a los comprendidos
         en los anexos de la Concesion previa autorizacion de la Secretaria. Al
         efecto, el Concesionario debera presentar solicitud a satisfaccion de
         la Secretaria, que cumpla con los requisitos del articulo 24 de la Ley
         y demas disposiciones que resulten aplicables, sin perjuicio de que, de
         requerir concesiones sobre bandas de frecuencias del espectro
         radioelectrico, estas se otorgaran mediante el procedimiento de
         licitacion publica previsto por el articulo 14, asi como por los demas
         aplicables de la Ley.

         Para obtener la autorizacion o concesion mencionadas en el parrafo
         anterior, el Concesionario debera estar al corriente en el cumplimiento
         de las obligaciones derivadas de la presente Concesion.

         En los terminos del articulo 33 de la Ley, el Concesionario podra
         prestar servicios de valor agregado, bastando que previamente los
         registre ante la Comision.

1.3.     Modificacion de cobertura. Para que el Concesionario pueda modificar el
         area de cobertura de la Red, requerira de la autorizacion previa de la
         Comision, salvo en el caso de modificaciones a la cobertura sobre
         bandas del espectro radioelectrico, las cuales, en su caso, deberan ser
         autorizadas por la Secretaria.

         La Comision o la Secretaria, segun sea el caso, resolvera sobre la
         solicitud para la modificacion de la cobertura de la Red del
         Concesionario en un plazo no mayor a 120 dias naturales contados a
         partir de la


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                                      -3-


          recepcion de la solicitud, siempre que el Concesionario se encuentre
          al corriente en el cumplimiento de las obligaciones derivadas de la
          Concesion.

1.4.     Vigencia. La vigencia de esta Concesion sera de 20 anos contados a
         partir de la fecha de su firma y podra ser prorrogada de acuerdo con lo
         senalado por el articulo 27 de la Ley.

1.5.     Legislacion aplicable. La instalacion, operacion y explotacion de la
         Red y de los servicios comprendidos en la Concesion, debera sujetarse a
         la Constitucion Politica de los Estados Unidos Mexicanos, la Ley y las
         Leyes supletorias senaladas en el articulo 8 del citado ordenamiento
         legal, asi como a los tratados internacionales, leyes, reglamentos,
         decretos, normas oficiales mexicanas, resoluciones, acuerdos,
         circutares y demas disposiciones administrativas que expida la
         Secretaria o la Comision, asi como a las condiciones establecidas en
         esta Concesion.

         El Concesionario acepta que si los preceptos legales y las
         disposiciones administrativas a que se refiere el parrafo anterior y a
         las cuales queda sujeta esta Concesion, fueren derogados, modificados o
         adicionados, el Concesionario quedara sujeto a la nueva legislacion y
         disposiciones administrativas, a partir de su entrada en vigor.

1.6.     Otras Concesiones. La Concesion no confiere derechos de exclusividad al
         Concesionario, por lo que la Secretaria, dentro de la misma area
         geografica, podra otorgar otras concesiones a favor de terceras
         personas para instalar, operar y explotar una o mas redes publicas de
         telecomunicaciones, para que se presten servicios identicos o similares
         a los comprendidos en esta Concesion.

1.7.     Cesion de derechos. El Concesionario podra ceder parcial o totalmente
         los derechos y obligaciones establecidos en la Concesion, en los
         terminos del articulo 35 de la Ley y demas disposiciones legales,
         reglamentarias y administrativas aplicables.

1.8.     Prestacion de los servicios a traves de filiales o subsidiarias. Previa
         autorizacion de la Secretaria, el Concesionario podra prestar los
         servicios comprendidos en esta Concesion a traves de empresas filiales
         o subsidiarias, siempre que acredite a satisfaccion de esta, que dichas
         empresas cuentan con la capacidad financiera necesaria para la
         prestacion de los servicios en cuestion. No obstante lo anterior, en
         todo momento, el Concesionario sera el unico responsable ante la
         Secretaria, la Comision y cualquier autoridad competente, por el
         estricto cumplimiento de las obligaciones derivadas de la Concesion.

1.9.     Poderes o mandatos. En ningun caso el Concesionario podra otorgar
         poderes o mandatos generales para actos de administracion o de dominio
         con caracter de irrevocables, que tengan por objeto o hagan posible al
         apoderado o mandatario el ejercicio de los derechos y obligaciones
         contemplados en la Concesion.

1.10.    Gravamenes. Cuando et Concesionario constituya algun gravamen sobre la
         Concesion o los derechos derivados de ella, debera efectuar el registro
         a que se refiere el articulo 64 de la Ley, dentro de los 30 dias
         naturales siguientes a la fecha de su constitucion.

         El documento en que conste la garantia otorgada debera establecer,
         expresamente, que la ejecucion de la misma en ningun caso otorgara el
         caracter de concesionario al acreedor.


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                                      -4-


         Para que la Concesion le sea adjudicada al acreedor o a un tercero, se
         requerira que la Secretaria autorice la cesion de derechos en los
         terminos del articulo 35 de la Ley o bien, que obtenga concesion de
         conformidad con el articulo 24 del mismo ordenamiento, sin que en este
         ultimo caso se encuentren comprendidas bandas de frecuencias del
         espectro radioelectrico.

1.11.    Nacionalidad. El Concesionario no tendra en relacion con esta Concesion
         mas derechos que los que las leyes mexicanas conceden a los mexicanos
         y, por consiguiente, la sociedad y sus socios extranjeros, en su caso,
         se comprometen a no pedir ni aceptar la intervencion diplomatica de
         algun pais extranjero, bajo la pena de perder, en beneficio de la
         nacion mexicana, todos los bienes y derechos que hubiesen adquirido
         para instalar, operar y explotar la Red.

1.12.    Inversion neutra. En terminos del Titulo Quinto de la Ley de Inversion
         Extranjera, la inversion neutra no se computara para determinar el
         porcentaje de inversion extranjera en el capital social del
         Concesionario.

1.13.    Empresas con participacion estatal de paises extranjeros. No se
         considerara como participacion accionaria de un gobierno o estado
         extranjero, la que realicen empresas con participacion estatal de
         paises extranjeros que no sean consideradas como autoridades por la
         legislacion interna del pais de origen, y que tengan personalidad
         juridica y patrimonio propios.

1.14.    Suscripcion y enajenacion de acciones o partes sociales. El
         Concesionario se obliga a presentar a la Secretaria y a la Comision, a
         mas tardar el 30 de abril de cada ano, una relacion de sus diez
         principales accionistas y sus respectivos porcentajes de participacion,
         a la que acompanara la informacion que determine la Comision.

         En caso de cualquier supuesto de suscripcion o enajenacion de acciones
         o partes sociales en un acto o sucesion de actos, que represente el
         diez por ciento o mas del monto del capital social de la sociedad, el
         Concesionario se obliga a observar el regimen siguiente:

1.14.1.           El Concesionario debera dar aviso a la Secretaria de la
                  intencion de los interesados en realizar la suscripcion o
                  enajenacion de las acciones o partes sociales, debiendo
                  acompanar el aviso con la informacion de las personas
                  interesadas en adquirir las acciones o partes sociales;

1.14.2.           La Secretaria tendra un plazo de 90 dias naturales, contados a
                  partir de la presentacion del aviso, para objetar por escrito
                  y por causa justificada la operacion de que se trate, y

1.14.3.           Transcurrido dicho plazo sin que la operacion hubiere sido
                  objetada por la Secretaria, se entendera por aprobada.

         Solo las operaciones que no hubieren sido objetadas por la Secretaria
         podran, en su caso, inscribirse en el libro de registro de accionistas
         o socios de la persona moral, sin perjuicio de las autorizaciones que
         se requieran de otras autoridades conforme a las disposiciones
         aplicables. No se requerira presentar el aviso a que se refiere el
         numeral 1.14.1. anterior, cuando la suscripcion o enajenacion se
         refiera a acciones o partes sociales representativas de inversion
         neutra en terminos de la Ley de Inversion Extranjera, o cuando se trate
         de aumentos de capital que sean suscritos por los mismos accionistas,
         siempre que en este ultimo caso no se modifique la proporcion de la
         participacion de cada uno de ellos en el capital social.


<PAGE>
                                      -5-


         En caso de que el interesado en suscribir o adquirir las aciones o
         partes sociales sea una persona moral, en el aviso al que se refiere la
         condicion 1.14.1. anterior, debera presentarse la informacion necesaria
         para que la Secretaria conozca la identidad de las personas fisicas que
         tengan intereses patrimoniales mayores al diez por ciento del capital
         de dicha persona moral.

         Esta condicion debera incluirse en los estatutos sociales, asi como en
         los titulos o certificados que emita el Concesionario.

1.15.    Capacitacion y desarrollo tecnologico. El Concesionario desarrollara
         programas de adiestramiento y capacitacion de su personal. Asimismo, el
         Concesionario debera llevar a cabo labores de investigacion y
         desarrollo en el pais.

1.16.    Designacion de responsable tecnico. El Concesionario se obliga a
         designar ante la Comision un responsable del funcionamiento tecnico de
         la Red, quien contara con las facultades de administracion necesarias
         para obligar al Concesionario ante la Comision con respecto a la
         operacion tecnica de la misma Red.

                                Capitulo Segundo.
                    Disposiciones aplicables a los servicios.

2.1.     Calidad de los servicios. El Concesionario se obliga a prestar los
         servicios comprendidos en esta Concesion en forma continua y eficiente,
         de conformidad con la legislacion aplicable y las caracteristicas
         tecnicas establecidas en la Concesion y sus anexos.

         Asimismo, el Concesionario se obliga a instrumentar los mecanismos
         necesarios para poder llevar a cabo las reparaciones de la Red o las
         fallas en los servicios, dentro de las ocho horas siguientes a la
         recepcion del reporte.

         El Concesionario buscara que los servicios comprendidos en la
         Concesion, se presten con las mejores condiciones de precio, diversidad
         y calidad en beneficio de los usuarios, a fin de promover un desarrollo
         eficiente de las telecomunicaciones. Para ello, debera enviar a la
         Comision, dentro de los ciento veinte dias naturales siguientes a la
         fecha de firma de esta Concesion, los estandares minimos de calidad de
         los servicios, sin perjuicio de que la Comision expida al efecto reglas
         de caracter general.

2.2.     Interrupcion de los servicios. En el supuesto de que se interrumpa la
         prestacion de alguno de los servicios durante un periodo mayor a 72
         horas consecutivas, contado a partir de la fecha establecida en el
         reporte respectivo, el Concesionario bonificara a los usuarios la parte
         de la cuota correspondiente al tiempo que dure la interrupcion.

2.3.     Sistema de quejas y reparaciones. El Concesionario debera establecer un
         sistema para la recepcion de quejas y la reparacion de fallas.

         Mensualmente, el Concesionario debera elaborar un reporte que incluira
         la incidencia de fallas por tipo, las acciones correctivas adoptadas y
         las bonificaciones realizadas, mismo que estara a disposicion de la
         Comision.


<PAGE>
                                      -6-


         La Comision podra hacer del conocimiento publico dicha informacion
         conjuntamente con la de otros concesionarios que presten servicios
         similares en el pais o en la misma region.

2.4.     Equipo de medicion y control de calidad. El Concesionario se obliga a
         tomar las medidas necesarias para asegurar la precision y confiabilidad
         de los equipos que utilice para la medicion de la calidad y para la
         facturacion de los servicios. Para estos efectos, el Concesionario
         debera efectuar pruebas de calibracion a sus equipos y proporcionar a
         la Comision, cuando esta lo requiera, los resultados de las mismas por
         trimestre calendario y, en su caso, los documentos donde conste que se
         han realizado los ajustes correspondientes.

         Asimismo, el Concesionario debera mantener los registros de los
         equipos de medicion que la Comision determine.

2.5.     Codigo de practicas comerciales. El Concesionario debera integrar, de
         conformidad con las reglas de caracter general que al efecto expida la
         Comision, un codigo de practicas comerciales en el que describira, en
         forma clara y concisa, los diferentes servicios que proporcione y la
         metodologia para la aplicacion de las tarifas correspondientes. Una vez
         integrado dicho codigo y previa autorizacion de la Comision, el
         Concesionario debera tenerlo disponible al publico en sus oficinas
         comerciales y publicar un extracto del mismo en uno de los diarios de
         mayor circulacion a nivel nacional.

2.6.     Servicios de emergencia. El Concesionario debera poner a disposicion de
         la Comision, dentro de los seis meses siguientes a la expedicion de la
         Concesion, un plan de acciones para prevenir la interrupcion de los
         servicios, asi como para proporcionar servicios de emergencia, en casos
         fortuitos o de fuerza mayor.

         En la eventualidad de una emergencia y dentro de su area de cobertura,
         el Concesionario proporcionara los servicios indispensables que indique
         la Comision en forma gratuita solo por el tiempo y en la proporcion que
         amerite la emergencia.

         El Concesionario debera dar aviso a la Secretaria y a la Comision de
         cualquier evento que repercuta en forma generalizada o significativa en
         el funcionamiento de la Red.

                                Capitulo Tercero.
                                    Tarifas.

3.1.     Cobro indebido de tarifas. Si el Concesionario llegare a cobrar a los
         usuarios tarifas no registradas o distintas de las establecidas, en su
         caso, conforme a los articulos 61 y 63 de la Ley, debera reembolsar a
         los mismos la diferencia con respecto a las tarifas registradas o
         establecidas.

         Lo anterior, sin perjuicio de las sanciones que se impongan de
         conformidad con la Ley y demas disposiciones legales, reglamentarias y
         administrativas aplicables.

3.2.     Prohibicion de subsidios cruzados. La Comision podra verificar en todo
         momento que las tarifas registradas no constituyan subsidios cruzados
         en terminos del articulo 62 de la Ley, para cuyo efecto, el
         Concesionario debera proporcionar la informacion correspondiente dentro
         de los sesenta dias naturales siguientes a la fecha en que reciba la
         solicitud de la Comision.


<PAGE>
                                      -7-


3.3.     Facturacion. Los sistemas de facturacion del Concesionario deberan ser
         previamente aprobados por la Comision.

                                Capitulo Cuarto.
                           Verificacion e Informacion.

4.1.     Sin perjuicio de las facultades de la Comision de requerir otra
         informacion al Concesionario en terminos del articulo 68 de la Ley,
         este debera entregar a la Comision. dentro de Ios ciento cincuenta dias
         naturales siguientes al cierre del ejercicio correspondiente:

4.1.1.   Los estados financieros auditados de su empresa desglosados por
         servicio y, en su caso, por area geografica;

4.1.2.   Una descripcion de los principales activos fijos del Concesionario quo
         comprende la Red, de conformidad con los formatos que establezca la
         Comision, y

4.1.3.   Un informe sobre las acciones llevadas a cabo respecto de los programas
         de adiestramiento y capacitacion de su personal, asi coma de las
         labores de investigacion y desarrollo en el pais, segun se establece en
         la condicion 1.15 de esta Concesion.

4.2.     El Concesionario debera informar trimestralmente a la Comision sobre el
         avance del programa de expansion de la Red.

4.3.     El Concesionario debera poner a disposicion de la Comision la
         informacion estadistica de trafico, enrutamiento, ocupacion,
         rendimiento u otros parametros de operacion generada por la Red, de
         conformidad con las disposiciones de caracter general que al efecto
         expida la Comision. Asimismo, debera proporcionar informacion contable
         por servicio, region, funcion y componentes de la Red, previa
         aprobacion por parte de la Comision de la metodologia y periodicidad
         correspondientes.

                                Capitulo Quinto.
                                   Garantias.

5.       El Concesionario establecera, a satisfaccion de la Secretaria, las
         garantias relativas al cumplimiento de las obligaciones derivadas de
         esta Concesion, en la forma y terminos establecidos en los anexos de la
         Concesion.

                                 Capitulo Sexto.
                           Jurisdiccion y competencia.

6.       Para todo lo relativo a la interpretacion y cumplimiento de la
         Concesion, salvo lo que administrativamente corresponda resolver a la
         Secretaria o a la Comision, el Concesionario conviene en someterse a la
         jurisdiccion de los Tribunales Federales de la Ciudad de Mexico,
         Distrito Federal, renunciando al fuero que pudiere corresponderle en
         razon de su domicilio presente o futuro.


<PAGE>
                                      -8-



                  Mexico, Distrito Federal, 1 de abril de 1998.

                   SECRETARIA DE COMMUNICACIONES Y TRANSPORTES
                                  EL SECRETARIO





                              CARLOS RUIZ SACRISTAN






                                EL CONCESIONARIO
                  TELEFONIA INALAMBRICA DEL NORTE, S.A. DE C.V.




                               TOMAS MILMO SANTOS
                               REPRESENTANTE LEGAL