Jeco Corp. is a Japanese joint venture established in 1988 by Mitsubishi Corp. (70%), Nippon Mining & Metals Co., Ltd. (20%) and Mitsubishi Materials Corp. (10%). It owns a 10% stake in Minera Escondida, the operator of the world's largest copper mine in Chile's Antofagasta region (II). In 2010, the three companies formed a new JV, Jeco 2 Ltd., to increase their ownership in Escondida by 2.5%. Jeco 2 has a capital structure consisting of 50% ownership by Mitsubishi Corp, with Nippon Mining & Metals holding a 40% and the balance held by Mitsubishi Materials. The Escondida mine is a copper porphyry deposit that also produces gold and silver. The project comprises two open pits and two concentrator plants that produce copper concentrate. Escondida has processed over 2Bt of ore in 25 years operation.