The miners' union expressed concern about the construction workers' plans to force their way into the mine on Jan. 9.

Production was down 16% at Codelco, while it jumped 6.3% at Escondida and rose 2.8% in Collahuasi.

Chief executive Mark Bristow approached some of First Quantum’s largest investors late last year, according to Bloomberg sources.

Teck has a first option to earn a 55% interest over three years, and the two companies will form a joint venture thereafter.

Teck will have the option to acquire an 80% interest in La Coipita by funding cumulative exploration expenditures of $20 million over a five-year period.

Factory activity at the world's biggest metals consumer expanded at a quicker pace in December.

Bondholders have until Jan. 2 to give an early consent on a plan to push out due dates on $3.2 billion in bond repayments.