Exhibit 8.1



Significant Subsidiaries and Investees



The following table sets forth our significant subsidiaries and investees accounted for using the equity method at May 31, 2005:



|                                                              |  |                              |  |                                          |  |                                                                                                                                                    
|------------------------------------------------------------- |  | ---------------------------- |  | ---------------------------------------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------
|Name of Company                                               |  | Jurisdiction ofEstablishment |  | Percentage ofOwnershipand VotingInterest |  | Description                                                                                                                                        
|Controladora de Servicios de Telecomunicaciones, S.A. de C.V. |  | Mexico                       |  | 100.0%                                   |  | Intermediate holding company                                                                                                                       
|                                                              |  |                              | 
|Alquiladora de Casas, S.A. de C.V.                            |  | Mexico                       |  | 100.0%                                   |  | Real estate company owning our facilities                                                                                                          
|                                                              |  |                              | 
|Anuncios en Directorios, S.A. de C.V.                         |  | Mexico                       |  | 100.0%                                   |  | Producer of yellow pages directories                                                                                                               
|                                                              |  |                              | 
|Compañía de Teléfonos y Bienes Raíces, S.A. de C.V.           |  | Mexico                       |  | 100.0%                                   |  | Real estate company owning our facilities                                                                                                          
|                                                              |  |                              | 
|Consorcio Red Uno, S.A. de C.V.                               |  | Mexico                       |  | 100.0%                                   |  | Supplier of telecommunications network integration services and information systems                                                                
|                                                              |  |                              | 
|Teléfonos del Noroeste, S.A. de C.V., or Telnor               |  | Mexico                       |  | 100.0%                                   |  | Fixed-line network concessionaire for the state of Baja California Norte and the San Luis Rio Colorado region of the state of Sonora               
|                                                              |  |                              | 
|Uninet, S.A. de C.V.                                          |  | Mexico                       |  | 100.0%                                   |  | Provider of corporate networks services and Internet access to Telmex and commercial customers                                                     
|                                                              |  |                              | 
|Telmex USA, L.L.C.                                            |  | Delaware                     |  | 100.0%                                   |  | Authorized reseller of long distance services and holder of FCC authorization to provide facility-based long distance services in the United States
|                                                              |  |                              | 
|Latam Telecomunicaciones LLC                                  |  | Delaware                     |  | 100.0%                                   |  | Holding company for non-Mexican subsidiaries and investments                                                                                       
|                                                              |  |                              | 
|Embratel Participações S.A.                                   |  | Brazil                       |  | 95.1%(1)                                 |  | Intermediate holding company of subsidiary that provides domestic and international long distance, local and data services in Brazil               
|                                                              |  |                              | 
|Empresa Brasileira de Telecomunicações S.A.  EMBRATEL        |  | Brazil                       |  | 94.0%(1)                                 |  | Provider of domestic and international long distance, local and data services in Brazil                                                            
|                                                              |  |                              | 
|Star One S.A.                                                 |  | Brazil                       |  | 75.2%                                    |  | Provider of satellite services in Brazil                                                                                                           
|                                                              |  |                              | 
|Telmex do Brasil, Ltda.                                       |  | Brazil                       |  | 100.0%                                   |  | Provider of telecommunications services to corporate customers in Brazil                                                                           
|                                                              |  |                              | 
|Telmex Chile Holding, S.A.                                    |  | Chile                        |  | 100.0%                                   |  | Holding company for assets acquired from AT&T Latin America Corp. in Chile                                                                         
|                                                              |  |                              | 
|Telmex Corp. S.A. (formerly Chilesat Corp S.A.)               |  | Chile                        |  | 99.3%                                    |  | Intermediate holding company whose subsidiaries provide long distance, Internet and data network services in Chile                                 
|                                                              |  |                              | 
|Techtel-LMDS Comunicaciones Interactivas, S.A.                |  | Argentina                    |  | 93.4%                                    |  | Provider of wireless voice, data and video transfer services and local and long distance fixed-line voice services in Argentina                    



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|                                   |  |                              |  |                                          |  |                                                                            
|---------------------------------- |  | ---------------------------- |  | ---------------------------------------- |  | ---------------------------------------------------------------------------
|Name of Company                    |  | Jurisdiction ofEstablishment |  | Percentage ofOwnershipand VotingInterest |  | Description                                                                
|Telmex Argentina S.A.              |  | Argentina                    |  | 100.0%                                   |  | Provider of telecommunications services to corporate customers in Argentina
|                                   |  |                              | 
|Metrored Telecomunicaciones S.R.L. |  | Argentina                    |  | 83.4%                                    |  | Provider of data services in Argentina                                     
|                                   |  |                              | 
|Telmex Colombia S.A.               |  | Colombia                     |  | 100.0%                                   |  | Provider of telecommunications services to corporate customers in Colombia 
|                                   |  |                              | 
|Telmex Perú S.A.                   |  | Peru                         |  | 100.0%                                   |  | Provider of telecommunications services to corporate customers in Peru     
|                                   |  |                              | 
|Grupo Telvista S.A. de C.V.(2)     |  | Delaware                     |  | 45.0%                                    |  | Provider of telemarketing services in the United States and Mexico         
|                                   |  |                              | 
|TM & MS, LLC(2)                    |  | Delaware                     |  | 50.0%                                    |  | Joint venture with Microsoft to operate an Internet portal (T1MSN)         

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|(1) | Corresponds to voting interest. Our effective ownership of the total capital of Embratel Participações S.A. is 63.9% and of Empresa Brasileira de
Telecomunicações S.A.  EMBRATEL is 63.1%.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(2) | Investments accounted for using the equity method.
|--- | --------------------------------------------------



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