Petrobras has begun negotiations for exploration contracts covering four offshore blocks in Ghana's Keta Basin, extending the Brazilian energy company's push to build an upstream position outside Brazil.

Ghana's Ministry of Energy and Green Transition approved Petrobras's application to negotiate the acreage after the company submitted an expression of interest in the basin, Petrobras said in a securities filing. The approval moves the company into direct talks over contract terms.

The Keta Basin sits offshore southeastern Ghana, on the West African coast. Petrobras has not disclosed the names of the four blocks, their acreage size, or the size of the interest it is seeking.

Sylvia Anjos, Petrobras's executive director of exploration and production, told Reuters the Ghanaian acreage shares geological similarities with Brazil's Equatorial Margin, where the company has ramped up exploration in recent years.

The talks fit into a broader effort by Petrobras to rebuild its reserves through exploration in frontier basins. The company has said it is evaluating prospects in Brazil and abroad as it diversifies beyond its mature producing fields.

CEO Magda Chambriard has said Africa is set to become Petrobras's main exploration region outside Brazil. Beyond Ghana, the company is assessing opportunities in São Tomé and Príncipe, Namibia, Côte d'Ivoire and South Africa, according to Reuters.

Petrobras has already put that strategy into practice. In July, it completed the acquisition of a 75% operating interest in offshore Block 3 in São Tomé and Príncipe, adding to a growing African upstream footprint.

No timetable has been set for concluding the Ghana negotiations or for starting exploration in the Keta Basin.