| COMPANY                                       |   | COUNTRY OFINCORPORATION |   | OWNERSHIP % |   | VOTING % |
|-----------------------------------------------|--------|-------------------------|--------|-------------|--------|----------|
|                                          |   |                    |   |        |   |     |
| Ecopetrol      Oleo e Gas do Brasil Ltda*     |   | Brazil                  |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Ecopetrol      del Perú S.A.*            |   | Peru                    |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Ecopetrol      America Inc.*                  |   | United      States      |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Black      Gold Re                            |   | Bermuda                 |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Andean      Chemicals Ltd.                    |   | Bermuda                 |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| ODL      Finance S.A.                         |   | Panama                  |   | 65          |   | 65       |
|                                          |   |                    |   |        |   |     |
| Propilco      S.A.*                           |   | Colombia                |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Bioenergy      S.A.**                         |   | Colombia                |   | 78.87       |   | 78.87    |
|                                          |   |                    |   |        |   |     |
| Ecopetrol      Global Energy S.L.U.           |   | Spain                   |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Ecopetrol      Pipelines International Ltd.** |   | Bermuda                 |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Ecopetrol      Transportation Company         |   | Cayman      Islands     |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Offshore      International Group Inc.(1)     |   | United      States      |   | 50          |   | 50       |
|                                          |   |                    |   |        |   |     |
| Petrotech      Peruana S.A.**(1)              |   | Peru                    |   | 50          |   | 50       |
|                                          |   |                    |   |        |   |     |
| Ecodiesel      Colombia S.A.(1)               |   | Colombia                |   | 50          |   | 50       |
|                                          |   |                    |   |        |   |     |
| Refinería      de Cartagena S.A.*        |   | Colombia                |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Serviport      S.A.(1)                        |   | Colombia                |   | 49          |   | 49       |
|                                          |   |                    |   |        |   |     |
| Oleoducto      de Colombia S.A.*              |   | Colombia                |   | 65.57       |   | 65.57    |
|                                          |   |                    |   |        |   |     |
| Oleoducto      Central S.A.*                  |   | Colombia                |   | 60          |   | 60       |
|                                          |   |                    |   |        |   |     |
| Hocol      Petroleum Limited                  |   | Bermuda                 |   | 100         |   | 100      |
|                                          |   |                    |   |        |   |     |
| Invercolsa      S.A.(1)                       |   | Colombia                |   | 31.76       |   | 31.76    |

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