Global mining giant Rio Tinto Ltd has signed two agreements with the world’s largest copper producer CODELCO, to explore for the base metal in Chile.

The first agreement covers the Esteli prospect which adjoins the Exploradora property in northern Chile. 

The second agreement covers the Paloma prospect near the El Tesoro min and the BHP Billiton Ltd-operated Spence copper mine, a region that provides about a third of the world’s copper output.

The agreements strengthen the relationship between two copper giants that are struggling to raise output as ore grades fall at their biggest mines.
Rio Tinto can earn a 55 per cent interest in each prospect through stand alone exploration investments of $US20 million ($A23.92 million), with an option to increase its stake to 60 per cent.

CEO of Rio Tinto copper Bret Clayton said in a statement today “We are very pleased to enter into these additional agreements which strengthen Rio Tinto’s relationship with CODELCO and provide access to some of the most prospective copper tenement in the world”.

The agreements were signed between Rio Tinto and CODELCO subsidiary CCM Los Andes.
Rio Tinto is the subject of a $US140 billion ($A167.42 billion) takeover proposal from rival BHP Billiton, the world’s largest mining company.

European Union antitrust regulators have requested more information from BHP Billiton on the proposed takeover and put the antitrust probe on hold.