Exhibit 21

Subsidiaries of the Registrant

Name, Jurisdiction                                                                                                           Relationship

Apco Argentina S.A. (Argentine corporation) Subsidiary owned 95% by Apco Oil and Gas International Inc.

Apco Properties Ltd. (Cayman Islands company) Subsidiary owned 100% by Apco Oil and Gas International Inc.

Apco Austral S.A. (Argentine corporation) Subsidiary owned 95% by Apco Oil and Gas International Inc.