The Saudi Public Investment Fund has made an offer to acquire a stake in Vale's nickel and copper mining unit in Brazil for $2.5 billion, according to Bloomberg. Informed sources indicate that the fund could acquire about a ten percent stake in the unit through a joint venture established in January with Saudi mining company Ma'aden. The report noted that the fund has a significant opportunity to outperform competitors, including Japan's Mitsui and the Qatar Investment Authority, and that reaching a formal agreement may take several weeks. The Brazilian newspaper Valor Economico reported that Vale received binding offers to purchase a stake in its base metals unit in May.