Brazil's antitrust watchdog, CADE, has unconditionally approved the joint acquisition of a controlling stake in Brazilian aluminum producer Companhia Brasileira de Alumínio (CBA) by Rio Tinto and Chinalco. 

The approval, published in the official gazette on Wednesday, removes the last regulatory barrier for the $910 million deal first announced in January.

Under the agreement, the investment will be managed through a joint venture, with a Chinalco subsidiary holding a 67% stake and Rio Tinto owning the remaining 33%.

CBA operates a low-carbon, vertically integrated aluminum business, powered by its own hydroelectric and wind assets. The acquisition allows Rio Tinto to further expand its footprint in low-carbon aluminium through this strategic partnership.