Ecopetrol, Colombia’s state-run oil company, has agreed to a partnership with Japan’s Nippon Oil to explore Brazil’s Amazon basin for possible oil reserves.

The contract, signed by Ecopetrol and Nippon Oil’s Brazilian subsidiary, permits the Colombian company to explore a block of land in the Foz basin of Brazil’s Amazon rainforest.

Founded in 1888, Nippon Oil is the largest oil company in Japan. The company has significantly expanded its operations outside of Japan in the last decade, with interests in regions including the North Sea, Malaysia, Vietnam, and North America.

According to the agreement, Nippon Oil will collaborate with Ecopetrol in exploration efforts and retain a 30% stake in potential discoveries. Ecopetrol will keep the remaining 70% of the deal and continue to act as operator in the plan.

Ecopetrol’s president, Juan Carlos Echeverry, expressed optimism for the upcoming partnership in a statement released this week:

“This partnership (with Nippon Oil) is in line with our new strategy to position ourselves as a Pan American company with a growing offshore exploration effort in Colombia, the Gulf of Mexico and Brazil, while diversifying risk with world-class companies.”

The FZA-M-320 Block, as the area that will be explored is known, is currently in its first phase of a five-year exploration period. It is not the only area of Brazil in which Ecopetrol maintains a presence: the company also participates in EC-M-715 block in the Ceara basin in a partnership with American multinational oil company Chevron, and well in the POT-M-567 block in the Potiguar basin.