South Africa’s precious metals company Sibanye-Stillwater has instructed three leading law firms as legal advisors on its purchase of the Santa Rita nickel mine and Serrote copper mine in Brazil for $1 billion.

U.K.-headquartered Clifford Chance, South African firm Cliffe Dekker Hofmeyr, and Brazilian firm Machado Meyer are all advising Sibanye-Stillwater on the deal, according to a statement by the metals company.