Exhibit 8.1

List of Subsidiaries of Petrobras Argentina S.A.



|                                                            |  |              |  |                          |        |  |          |  |        |                  |  |                                       
|----------------------------------------------------------- |  | ------------ |  | ------------------------ | ------ |  | -------- |  | ------ | ---------------- |  | --------------------------------------
|                                                            |  |              |  | % of Ownership and Votes |        |  |         
|Subsidiaries                                                |  | Country      |  | Direct                   |        |  | Indirect |  |        | Business segment
|Atalaya Energy S.R.L.                                       |  | Argentina    |  |                          | 95.00  |  |          |  | 5.00   |                  |  | Oil and Gas Exploration and Production
|Canadian Hunter Argentina S.A                               |  | Argentina    |  |                          | 95.00  |  |          |  | 5.00   |                  |  | Oil and Gas Exploration and Production
|Corod Producción S.A.                                       |  | Venezuela    |  |                          | 100.00 |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|EcuadorTLC S.A.                                             |  | Ecuador      |  |                          | 100.00 |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|Eg3 Red S.A.                                                |  | Argentina    |  |                          | 95.00  |  |          |  | 5.00   |                  |  | Refining and Distribution             
|Electricidade Com S.A.                                      |  | Brazil       |  |                          |       |  |          |  | 100.00 |                  |  | Gas and Energy                        
|Enecor S.A.                                                 |  | Argentina    |  |                          | 69.99  |  |          |  |       |                  |  | Gas and Energy                        
|Petrobras Bolivia Internacional S.A.                        |  | Bolivia      |  |                          | 100.00 |  |          |  |       |                  |  | Corporate                             
|Petrobras Energía Colombia                                  |  | Grand Cayman |  |                          |       |  |          |  | 100.00 |                  |  | Oil and Gas Exploration and Production
|Petrobras Energía de México S.A. de C.V.                    |  | Mexico       |  |                          |       |  |          |  | 100.00 |                  |  | Oil and Gas Exploration and Production
|Petrobras Energía Ecuador                                   |  | Grand Cayman |  |                          |       |  |          |  | 100.00 |                  |  | Oil and Gas Exploration and Production
|Petrobras Energía Internacional S.A.                        |  | Argentina    |  |                          | 95.00  |  |          |  | 5.00   |                  |  | Corporate                             
|Petrobras Energía Operaciones Ecuador S.A.                  |  | Ecuador      |  |                          |       |  |          |  | 100.00 |                  |  | Oil and Gas Exploration and Production
|Petrobras Hispano Argentina S.A.                            |  | Spain        |  |                          | 100.00 |  |          |  |       |                  |  | Corporate                             
|Petrolera San Carlos S.A.                                   |  | Venezuela    |  |                          |       |  |          |  | 100.00 |                  |  | Oil and Gas Exploration and Production
|Transporte y Servicios de Gas en Uruguay S.A.               |  | Uruguay      |  |                          | 51.00  |  |          |  | 13.55  |                  |  | Gas and Energy                        
|World Energy Business S.A.                                  |  | Argentina    |  |                          |       |  |          |  | 100.00 |                  |  | Gas and Energy                        
|Petrolera Entre Lomas S.A.                                  |  | Argentina    |  |                          | 58.88  |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|                                                            |  |              |  |                         
|Affiliates under joint control                              |  |              |  |                          |        |  |          |  |        |                  |  |                                       
|                                                            |  |              |  |                         
|Cía. de Inversiones de Energía S.A.                         |  | Argentina    |  |                          | 25.00  |  |          |  | 25.00  |                  |  | Gas and Energy                        
|Transportadora de Gas del Sur S.A.                          |  | Argentina    |  |                          |       |  |          |  | 25.50  |                  |  | Gas and Energy                        
|                                                            |  |              |  |                         
|Main affiliates in which significant influence is exercised |  |              |  |                          |        |  |          |  |        |                  |  |                                       
|                                                            |  |              |  |                         
|Coroil S.A.                                                 |  | Venezuela    |  |                          | 20.00  |  |          |  | 29.00  |                  |  | Oil and Gas Exploration and Production
|Inversora Mata S.A.                                         |  | Venezuela    |  |                          | 49.00  |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|Oleoducto de Crudos Pesados Ltd.                            |  | Grand Cayman |  |                          |       |  |          |  | 11.42  |                  |  | Oil and Gas Exploration and Production
|Oleoducto de Crudos Pesados S.A.                            |  | Ecuador      |  |                          |       |  |          |  | 11.42  |                  |  | Oil and Gas Exploration and Production
|Oleoductos del Valle S.A.                                   |  | Argentina    |  |                          | 23.10  |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|Petrokariña S.A.                                            |  | Venezuela    |  |                          | 29.20  |  |          |  | 5.29   |                  |  | Oil and Gas Exploration and Production
|Petroritupano S.A.                                          |  | Venezuela    |  |                          | 22.00  |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|Petroven-Bras S.A.                                          |  | Venezuela    |  |                          | 29.20  |  |          |  | 5.29   |                  |  | Oil and Gas Exploration and Production
|Petrowayú S.A.                                              |  | Venezuela    |  |                          | 36.00  |  |          |  |       |                  |  | Oil and Gas Exploration and Production
|Propyme S.G.R (in liquidation)                              |  | Argentina    |  |                          | 48.56  |  |          |  | 0.07   |                  |  | Corporate                             
|Refinería del Norte S.A.                                    |  | Argentina    |  |                          | 28.50  |  |          |  |       |                  |  | Refining and Distribution             
|Urugua-í S.A.                                               |  | Argentina    |  |                          | 29.33  |  |          |  |       |                  |  | Gas and Energy                        
|                                                            |  |              |  |                         
|Other interest in affiliates                                |  |              |  |                          |        |  |          |  |        |                  |  |                                       
|                                                            |  |              |  |                         
|Termoeléctrica José de San Martín S.A.                      |  | Argentina    |  |                          | 10.00  |  |          |  |       |                  |  | Gas and Energy                        
|Termoeléctrica Manuel Belgrano S.A.                         |  | Argentina    |  |                          | 10.00  |  |          |  |       |                  |  | Gas and Energy