Origin is purchasing a 51% interest in Energía Austral from Xstrata Copper, which will continue to own the remainder of the company.
Energía Austral may build a 1GW hydropower project in the Aysén region of southern Chile, which would become the country's second-largest hydro scheme.
Under the terms of the deal, Origin will pay $75m over the next three years to complete a detailed project feasibility study.
