SAO PAULO, Jan 29 (Reuters) - Aluminium Corporation of China (Chinalco) 601600.SS and Rio Tinto RIO.AX agreed to acquire a controlling stake in the Companhia Brasileira de Aluminio CBAV3.SA for 4.69 billion reais ($903.61 million), the firms said in filings issued late on Thursday in Brazil.

Chinalco and Rio Tinto agreed to buy 446.6 million shares, or a 68.6% stake, of the Brazilian aluminium producer for 10.50 reais each, they said. The controlling stake will be purchased from Brazilian conglomerate Grupo Votorantim, they added.

Chinalco and Rio Tinto said they will launch a tender offer for the remaining shares of Companhia Brasileira de Aluminio, also known as CBA, in a mandatory move under Brazilian regulations that can lead to the delisting of the firm from the Sao Paulo exchange B3.

Reuters reported earlier that Chinalco and Rio Tinto were close to announcing the deal for a controlling stake in CBA.

The acquisition price represented a 1.4% premium on CBA's closing price on Thursday.

Chinalco and Rio Tinto said the stake in CBA will be managed through a joint venture, owned 67% by a subsidiary of the Chinese firm and 33% by the Anglo-Australian miner.

CBA operates an integrated aluminium production chain that spans bauxite mining, refining and smelting. It also manufactures diverse primary aluminium products.

The Brazilian company's shares have more than doubled in the last 12 months, pushing its market capitalization to $1.27 billion as of Thursday, according to LSEG data.

The sale process also attracted interest from Emirates Global Aluminium (EGA), a UAE-based company jointly owned by Abu Dhabi's Mubadala sovereign wealth fund and Dubai's Investment Corporation of Dubai, Reuters has reported. However, negotiations with EGA did not advance.