Contact: (51 1) 442-0372 / 442-0377,

We anticipate risks, and provide effective solutions.

We are a Peruvian firm with more than 9 years of providing tax, accounting, financial and legal consultancy services with a comprehensive and multidisciplinary focus.

Quantum Group is the integration ofQuantum Consultores and Montalto Leon Asociados, representatives of Morison International, the world’s ninth largest consultancy and auditing firm with more than 90 members in 222 offices distributed in more than more than 60 countries.

The professional team of Quantum Group provides personalized attention to prevent contingencies and find solutions to all types of problems. One of the commitments we have assumed is the implementation of efficient accounting and tax structures in order to generate transparent and orderly processes that permit timely compliance of the formal and substantial obligations of our clients.

Providing a quality service and enjoying a high level of business satisfaction has enabled us to consolidate a client portfolio made up of companies and projects at a local and international level, both in the public as well as the private sector, which are leaders in their fields and contribute decisively to the national and regional economies.




Marysol León Huayanca

General Manager

She is Quantum Consultores´s Founder. She is a Certified Public Accountant with a master´s degree in Tax and fiscal policy of the University of Lima. She participated in courses like the Program for Owners of Companies in the University of Piura and International Tax in the Austral University (Argentina). Nowadays, she is member of the tax committee of the Lima Chamber of Commerce, the Peruvian Institute of Tax Research and Development and the International Fiscal Association (IFA) Peruvian group.

She represents our country in the tax and fiscal committee of the Inter American Accountancy Association.

It is important to note that she was Chairperson in the Tax Court and Director of Tax Law of the Chartered Institute of Public Accountants of Lima.

She is the author of the book “Auditoria Tributaria”, edited and published in 1999. Nowadays, she teaches in the postgraduate school of the University of Lima. She also teaches tax specialization courses, which are organized by the Chartered Institute of Public Accountants and different Peruvian and foreign universities.


Rossana Montalto Herrera

Financial Audit Manager

Executive with a success industrial and commercial career with knowledge in accountancy and a Master´s degree in Business Management. She also is specialized in accountancy, management and financial audit. She has experience in internal audit, implementation of internal control process, tax, organization, credit and payment management, liquid assets, costs and legal. She is an accountant with a great deal of experience in foreign and national companies. She obtained great results owning to her motivation, adaptability and her skill at leading a group.

She has analytical skills and she take decisions with ease, in fact she is working under pressure.



Ana María Cogorno

Associate to the Legal Area

Lawyer, she studied in the Pontifical Catholic University of Peru and graduated in the Federico Villareal University. In the public sector, she worked in the Tax Administration between 1971 and 1983. In the Tax Administration she worked through different areas such as claims, technical assistance, legal advice, direction of tax studies, audit direction. In the Ministry of Economy and Finance she worked through the Fiscal Policy Direction and she was advisor of the Ministry of Economy; in addition, she worked as chairperson of tax court between 1992 and 2013 (Courtroom 1 and 5 and Custom Duties). In the private sector, she was partner in the Romero Lawyers Firm (1983-1992). She is expert in tax law, procedural tax law and corporate law. She was professor of tax law in the Pontifical Catholic University of Peru, University of Lima and the Magistrature Academy.


Cesar Perez

Associated to the Labour Area

Lawyer graduated from the Pontifical Catholic University of Peru (1981) and graduated of the Master in International Economic Law from the same university (1990). He has a post graduated diploma in Financial Law granted by the Peruvian University of Applied Sciences and a post graduated diploma in Contracting by the University of San Marcos.

Dr. Pérez Vásquez has extensive experience in corporate law, commercial affairs and labor law, with special focus on negotiating and solving business disputes, particularly related to employment. It has been a leading partner for more than 20 years of Eduardo Ferrero Costa Law Firm. He currently directs the activities of the Pérez Vásquez & Associate law firm.

He is legal adviser and legal representative of several companies and institutions, domestic and foreign. He has been working as a legal counsel of Banco Minero del Peru and Liquidating Commissions of Banco Minero and Banco Industrial, among others. He is advisor in collective bargaining process, conciliation and labor arbitrations. It was Ad hoc Advisory of the Parliament and member of the Advisory Committee on Commercial Law and Securities Commission of the Bar Association of Lima.

Likewise, Dr. Pérez Vásquez has the title of Settlement Adjudicator awarded by the Ministry of Justice and a member of the Panel of Arbitrators of the Center for Conciliation and Arbitration of the Pontifical Catholic University of Peru and Arbitration Center of the Peruvian Chamber of Commerce (AMCHAM).

Since 1985 Dr. Perez Vasquez is Professor at the Faculty of Law at the Pontifical Catholic University of Peru, as well as the School of Business at University of Lima. He has also been Professor of Business Law at the Graduate School of the University of the Pacific.

He is a lecturer and author of several articles and essays of his specialty.



Eduardo Huayanca Garcia

Tax Audit Manager

He is a certified public accountant who studied Economics and Business in the Ricardo Palma University. He has a specialization in International Tax in Peruvian University of Applied Sciences. He has a great deal of experience in tax auditing and consultancy service. He is also a member of the Peruvian Institute of Tax Research and Tax Development (IPIDET).


Carlos Paredes Reátegui

Accountancy Financial Consultancy Manager

He is a certified public Accountant who studied in University of San Marcos. He has a Master in Education Management and specialized in Audit in the University of Lima. He is also an advisor specialized in IFRS in Peru and abroad.

He is a member in The Institute of Internal Auditors. She works in consultancy to Peruvian and Ecuadorean companies. He was an internal and external auditor. Nowadays, he is an IFRS professor in the Business School and Postgraduate School of the University of Lima. In addition, he is a professor in Postgraduate School in Peruvian University of Applied Sciences and Norther Private University.

Moreover, he is author of different books of IFRS.