Alberto Arias Sierra Metals BOD resignation. MM, it is my understanding that the withholding stockholder votes for Mr. Arias required him to offer his resignation from the BOD, and the board then to decide whether to accept it or not. Another BOD member, Ricardo Arrarte, also resigned. The chairman of the BOD accaepted the two resignation requests, thanked them for their service, and wished both to be successful in their future endeavors