The Taca Taca copper-gold porphyry deposit, owned by Canada's Global Copper, has been explored previously by several mining companies - including BHP - but engineers never developed the mine.Seeking to further shore up its defenses against takeover by BHP, Rio Tinto has agreed to spend up to $US203 million ($260.7 million) to gain control of the Taca Taca deposit in Argentina.

Rio can earn a 75 per cent interest in Taca Taca after paying Global Copper $US83 million over three years, completing 25,000 metres of drilling and taking responsibility for the first $US120 million of development funding.
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