Start-Up of New Copper Mine

Antofagasta Holdings PLC 9 November 1999 START-UP OF ANTOFAGASTA'S NEW COPPER MINE Commissioning begins at Los Pelambres LONDON: Tuesday, 9 November 1999 - Antofagasta Holdings P.L.C. (ANTO.L), the UK-listed mining group based in Chile, reports that commissioning has begun at the Los Pelambres copper mine located in Chile's IV Region. Development of the US$1.36 billion Los Pelambres project began in November 1997. During the development phase, nearly 50 million tonnes of surface rock was removed from the area of the open pit to gain access to the ore and 13 kilometres of underground tunnels were constructed for the conveyor system. In August 1999, crushing of ore from the open pit began and on October 29 the ore started to flow along part of the conveyor system to the concentrator stockpile. Commissioning started at the concentrator on October 30 producing copper concentrate to be pumped along a 120-kilometre pipeline to a new port facility at Los Vilos for filtering and shipping to overseas smelters. First production of filtered concentrate at the Port is expected at end November with first shipments at end December or early January 2000. When Los Pelambres reaches its capacity of 85,000 tpd by March 2000, it will produce an average of 271,000 tonnes a year of copper in concentrates in the first five years and 246,000 tonnes per year over the 30-year mine life. Cash costs over the mine life are expected to average around 43 cents per pound of copper, placing it among the lowest cost producers world-wide. Los Pelambres has proven and probable reserves of 887 million tonnes of ore grading 0.77% copper and 0.023% molybdenum and total resources of over 3 billion tonnes at an estimated grade of 0.65% copper. Only 31% of the total geological resources are included in the 30-year mine plan. Antofagasta holds a 60% equity interest in the project and the remaining 40% is held by a consortium of Japanese groups, comprising Nippon Mining & Metals Co. Ltd. (15%), Mitsubishi Materials Corp. (10%), Marubeni Corporation (8.75%), Mitsubishi Corporation (5%) and Mitsui and Co. Ltd. (1.25%). Antofagasta's principal operations are mining, rail and road transportation and water distribution. It also holds a 33.6% investment in Quinenco S.A., a diversified industrial and financial group operating in Latin America. Antofagasta has a current market capitalisation of approximately £830 million. Enquiries: Philip Adeane, Managing Director Email: itrevor@antofagasta.co.uk Hussein Barma, Chief Financial Officer Email: hbarma@antofagasta.co.uk Neil Herbert, Financial Controller Email: nherbert@antofagasta.co.uk Antofagasta Holdings Tel: +44 171 374 8091