Ernesto Balarezo, CEO & Director

Mr. Balarezo has solid management and corporate experience in leading multinational companies in the mining, cement and services industries. Today, he is an Independent Board Member in Compañía Minera Caravelí, Grupo LAR and Compañía Agrícola Chapi, as well as part of the Strategic Committees in Cobra and Spencer Stuart - Perú. He was also a Board member for AENZA (previously Graña y Montero) during its restructuring process.

During 2016 and 2017, Ernesto worked in the Presidency of the Council of Ministers, forming the Delivery Unit, which had the task of monitoring the progress of the 6 priority projects of the Government.

Before that, he held positions such as Executive Vice President for the Americas in Gold Fields Limited, and CEO of Gold Fields La Cima S.A. During this time his highlights were his contributions in the strategic definition and global results of the company and assisting in the formation of a world class team.

Previously, he worked for the Hochschild Group for 16 years. His last position was Vice President of Operations at Hochschild Mining, where he was responsible for five operations in Peru, Argentina and Mexico, as well as the mining projects in development. He also held the positions of General Manager of Hochschild Mining in Mexico and then in Peru, as well as Deputy General Manager and Finance Manager in Cementos Pacasmayo.

In addition, he has been Director of several companies related to the Hochschild Group, Gold Fields Ltd and Director - Founder of the Peruvian - South African Chamber. He has also made contributions as Director of Peru 2021 and in IPAE Acción Empresarial.

He has a master's degree in Industrial Management (MS) and a Bachelor in Industrial Engineering (BS), both degrees obtained at the University Texas A&M in USA. He has followed various courses of specialization in direction, management, finance, and human resources in institutions like Institute of Directors, Harvard, Wharton, INSEAD, IESE, among others.


Jean Pierre Fort, CFO

Mr. Fort brings more than a decade of financial and operational experience in the mining industry. He joined Sierra Metals in 2023 as head of business development and corporate finance where he is an important part of the team in strengthening the Company’s financial position while leading initiatives to raise the Company’s profile with capital markets. Previously, he was chief financial officer and head of corporate development at Silver Mountain Resources Inc., where he was instrumental in leading an initial public offering and several programs that improved their financial position. He has worked at RBC Capital Markets in the Investment Banking Mining & Metals team and at Volcan Compañia Minera S.A.A. in Peru in several operational, financial reporting, and investor relations positions. Mr. Fort holds an MBA from Rotman School of Management – University of Toronto, and a bachelor degree in business from Universidad de Lima in Peru.


Alberto Calle, Vice President, Human Resources

Mr. Calle’s professional career spans more than three decades in industries such as retail, banking, organizational consulting, and mining. His area of focus for the last 20 years has been in Human Capital, with 13 years dedicated to the large-scale mining industry. Mr. Calle previously held positions at MMG – Las Bambas as Human Resource Manager as well as various roles at Newmont Mining. There, he was Regional Manager of Human Resources when he undertook an international assignment to the Company’s corporate offices in Denver, Colorado, as Director of Human Resources Programs. In this role, he collaborated on global leadership development projects. Mr. Calle holds a degree from the Faculty of Administrative Sciences at the University of Lima as well as an MBA from the University of Piura and has completed courses in Executive Leadership at Daniels School of Business, Denver University and Executive Coaching at Teachers College of Columbia Business School, New York.


Astolfo Romero, Vice President, Health & Safety

Mr. Romero, a systems engineer with more than 30 years of experience in both the oil & gas and mining sectors. He graduated from Instituto Politécnico Universitario Santiago Mariño in Venezuela with a specialization in automation and control. Mr. Romero has a Master’s degree in Engineering Security, Health, and Environment from Universidad de Los Andes and a Master's degree in Mining Industry Management from Universidad de Viña del Mar, with a Black Belt Six Sigma Specialization, Cost Management Specialization. As a Postgraduate Teacher he received his Master's degree in Mining Management at GERENS and Pontificia Universidad Catolica del Peru. Before joining Sierra, over the last 11 years, Mr. Romero served in multiple management positions in Volcan Compania Minera (Glencore) in areas such as Health & Safety, Operational Excellence, and Human Development. Before joining Volcan, Mr. Romero served as a Project Manager at Dupont Safety Resources.


Carlos Garcia Rosales, Vice President, Technical

Mr. Garcia is a Mining Engineer with more than 35 years of experience, including international experience in precious and base metals operations. Over these years, Mr. Garcia has served in multiple key operating positions in companies such as Hochschild Mining and Glencore. Mr. Garcia’s experience includes Mining Operations, Corporate Technical Management, Planning Management and Budget Control, and Technical-Economic evaluation of both mining projects and operations. Mr. Garcia has also served as a professor of Strategic Management and Cost Control Management at the Universidad Nacional de Ingeniería (UNI) as well as a professor of Mining Processes at the Universidad de Lima, both in Peru.

Mr. Garcia holds a master's degree in Management and Development from the Universidad Nacional de Ingeniería (UNI) in Peru.


Patricia Kosa Muñoz, Vice President, Legal

Ms. Kosa is a lawyer with nearly 20 years of legal experience in the mining and energy sector. Prior to joining Sierra Metals, she served as the Legal and Compliance Director at Gold Fields, where she was a member of the Executive Committee and Compliance Officer. Her career also includes roles at Estudio Muñiz and OSINERGMIN (a state entity responsible for overseeing investment in Mining and Energy).

In addition, Ms. Kosa is a postgraduate professor at Esan Graduate Business School and the president of WAAIME Peru.

Ms. Kosa holds a law degree from the National University of San Marcos and a Masters in Finance and Corporate Law from ESAN University. She has specialized studies in law, legal management, negotiation, and compliance from Yale University, Northwestern University, Kellogg Management School, and the International Anticorruption Academy.


Claudio Cubillas, General Manager, Peru


Noel Menera, General Manager, Mexico