The poultry and pork processing giant has acquired the 33% stake in Avex that it did not already own.
The deal is estimated to be worth US$40.5m and should be completed within the first quarter of 2013.
Through the acquisition the company gains the remaining interest in the spreads and sauces companies Flora Dánica, Flora San Luis and GB Dan (Grupo Dánica), all headquartered in Argentina.
The move is part of BRF's strategy to enhance its presence in Argentina, which it hopes to develop as an export base. Avex is already one of the country's largest poultry producers and exporters.