Copper mining group Antofagasta has completed the sale of its water business to Colombian group Empresas Públicas de Medellín.On 23 April, the Chile-based group announced it had reached a deal to sell Aguas de Antofagasta S.A. for $960m (£625.4m) and expected the transaction to be completed by the end of May.Antofagasta's water division reported earnings before interest, tax, depreciation and amortisation of $75.1m, while its gross assets as of 31 December amounted to $212.4m.Antofagasta shares were down 1.19% to 757.38p at 10:03 on Wednesday.