Exhibit 8.1

Significant Subsidiaries and Investees

The following table sets forth our significant subsidiaries and investees accounted
for using the equity method:



|                                                             |  |                              |  |                                           |  |                                                                                                                                                    
|------------------------------------------------------------ |  | ---------------------------- |  | ----------------------------------------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------
|Name of Company                                              |  | Jurisdiction ofEstablishment |  | Percentage ofOwnership andVoting Interest |  | Description                                                                                                                                        
|Controladora de Servicios deTelecomunicaciones, 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.                         |  | 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 corporate 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



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|                                                       |  |                              |  |                                           |  |                                                                                                                                     
|------------------------------------------------------ |  | ---------------------------- |  | ----------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------
|Name of Company                                        |  | Jurisdiction ofEstablishment |  | Percentage ofOwnership andVoting Interest |  | Description                                                                                                                         
|Embratel Participações S.A.                            |  | Brazil                       |  | 97.3%(1)                                  |  | Intermediate holding company of subsidiary that provides domestic and international long distance, local and data services in Brazil
|                                                       |  |                              | 
|Telmex do Brasil, Ltda.                                |  | Brazil                       |  | 97.3%(2)                                  |  | Provider of telecommunications services to corporate customers in Brazil                                                            
|                                                       |  |                              | 
|Net Serviços de Comunicação S.A.                       |  | Brazil                       |  | 31.0%(2)(3)(4)                            |  | Provider of cable television and local telephone services and bidirectional broadband Internet access in Brazil                     
|                                                       |  |                              | 
|Empresa Brasileira de Telecomunicações S.A.  EMBRATEL |  | Brazil                       |  | 96.3%(1)(2)                               |  | Provider of domestic and international long distance, local and data services in Brazil                                             
|                                                       |  |                              | 
|Star One S.A.                                          |  | Brazil                       |  | 77.1%(2)                                  |  | Provider of satellite services in Brazil                                                                                            
|                                                       |  |                              | 
|PrimeSys Soluções Empresariais S.A.                    |  | Brazil                       |  | 96.3%(2)                                  |  | Provider of high level value-added services, such as net integration and outsourcing                                                
|                                                       |  |                              | 
|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                        |  | 99.7%                                     |  | Intermediate holding company whose subsidiaries provide long distance, Internet and data network services in Chile                  
|                                                       |  |                              | 
|Techtel-LMDS Comunicaciones Interactivas, S.A.         |  | Argentina                    |  | 100.0%                                    |  | Provider of wireless voice, data and video transfer services and local and long distance fixed-line voice services in Argentina     
|                                                       |  |                              | 
|Telmex Argentina S.A.                                  |  | Argentina                    |  | 100.0%                                    |  | Provider of telecommunications services to corporate customers in Argentina                                                         
|                                                       |  |                              | 
|Metrored Telecomunicaciones S.R.L.                     |  | Argentina                    |  | 100.0%                                    |  | 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.                            |  | Mexico                       |  | 45.0%(3)                                  |  | Provider of telemarketing services in the United States and Mexico                                                                  

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|(1) | Corresponds to Telmexs voting interest. Our effective ownership of the total capital of Embratel Participações S.A. is 72.3% and of Empresa Brasileira de
Telecomunicações S.A.  EMBRATEL is 71.6%.
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(2) | Corresponds to Telmexs indirect interest, held through Embratel Participações S.A.
|--- | -----------------------------------------------------------------------------------

|(3) | Investments accounted for using the equity method.
|--- | --------------------------------------------------

|(4) | Corresponds to interest in total capital.
|--- | -----------------------------------------



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