PRESS RELEASE: Both companies underwent a rigorous and independent assessment process to ensure that they worked to ICMM's sustainable development framework in order to be admitted.

Minsur operates in Peru and Brazil where it mines tin, gold, niobium and tantalum. In Peru, their San Rafael underground mine produces 9% of the world's tin and the company expects to complete the Mina Justa copper project in 2020.

Minera San Cristóbal is a world-class Bolivian mining company which has invested US$1.8 billion in the world's third-largest open-pit silver mine, which is also the fifth-largest zinc mine.

Tom Butler, CEO of ICMM, commented: "I am delighted to welcome these two new members to ICMM. Both have shown real leadership in their environmental and social performance and have valuable experience to share with our other members. With a portfolio of South American operations and headquarters in Bolivia and Peru, they will bring additional geographical diversity to the council."

Juan Luis Kruger, CEO of Minsur, said: "We are proud to be the first Peruvian company, as well as the first tin producer, to join ICMM, an institution with which we share the purpose of mining with principles. Sustainability is a major pillar of our business strategy and having been recognised by ICMM on our social and environmental standards is an honour and a true testimony of our commitment to sustainable mining."

Mitsuhiro Hirano, chairman of Minera San Cristóbal's Chairman, stated: "For Minera San Cristóbal it is important to be recognised for the work it does because its goal has always been to contribute to the development of the region in which it operates, the department of Potosí and Bolivia, through the methodical operation requirements given to us by our parent Company Sumitomo, Minera San Cristóbal has become Bolivia's largest and most important mine for zinc, lead and silver.

"Our entry to ICMM reaffirms our dedication to sustainable development and ethical corporate values, which Sumitomo has instilled in us since our first day of operations. With continued guidance and support, we will keep elevating the level of our Bolivian operation to grow and flourish."

Member companies' sustainability performance is independently assessed annually to ensure that their sustainability policies align with the ICMM 10 principles and mandatory requirements set out in supporting position statements.