Antamina is a polymetallic mining complex that produces copper, zinc and molybdenum concentrates, and silver and lead concentrates as by products. The mine is located in the district of San Marcos, Ancash Region, 200 km. from the city of Huaraz at an average altitude of 4,300 meters above sea level. The company has its own port, called Punta Lobitos located in the coastal province of Huarmey. Investment in Antamina (an initial investment of approximately U.S. $ 2.3 billion, plus U.S. $ 1.2 billion of investment in the expansion of its operations) is considered the highest in the history of Peruvian mining. Today it is among the largest Peruvian producers of copper and zinc concentrates and one of the ten largest mines in the world in terms of operating volume. Compania Minera Antamina SA is a company incorporated under Peruvian law, the product of a joint venture between four leading companies in the world mining industry. Antamina's shareholders are: • BHP Billiton (33.75%) • Xstrata (33.75%) • Teck (22.5%) • Mitsubishi Corporation (10%)