Riverstone, through its SPAV Vista Oil & Gas, acquired Apco Oil & Gas and Apco Argentina to indirectly control Petrolera Entre Lomas SA (PELSA) and the direct interests of the Medanito and Jagüel, Entre Lomas, Bajada del Palo and Agua Amarga exploitation concessions. The sellers are Pampa Energía S.A. and Pluspetrol Resources Corporation. Financial terms were not disclosed.