Her practice both in Portuguese and Spanish law is focused on cross border M&A, joint ventures and private equity transactions.

She regularly acts for private equity investors on their investments and divestments, and represents strategic investors in connection with cross border acquisitions and sales of privately owned companies and assets.

She has recently completed a number of major transactions in the infrastructures, energy, retail, real estate and financial industry sectors in Spain and Portugal. On an international level, she has extensive experience in advising M&A transactions of multinational companies in Europe, Latin America and the United States.

She worked at the Madrid office from 2004 to 2017 and is currently based in the Lisbon office, where she started her career in 1998.

Mariana Norton dos Reis is a member of the Portuguese and Madrid Bar Associations and was admitted to the New York State Bar Associations. She lectured in the Master in Business Law, Cross Border Mergers, at Universidad Autónoma de Madrid and in the Bachelor’s Degree in Law and Business Administration and Management at Universidad CEU San Pablo, Madrid.

Founder and coordinator of the Women in Business (WiB) program in Cuatrecasas.


  • Master of Laws (LL.M.) in Advanced Corporate Law & Securities
    Columbia Law School, New York, 1998

    Bachelor of Laws
    Faculdade de Direito da Universidade de Lisboa, Lisbon, 1997

    Named a Harlan Stone Fisk Scholar
    Columbia Law School, N.Y., 1998

    Received a scholarship
    The Luso-American Development Foundation, 2016

Directory Mentions

Recommended lawyer
Chambers Europe, Chambers Global, Legal 500, IFLR1000, Leaders League and Best Lawyers in Corporate and M&A, Private Equity, Governance & Compliance and Energy

Tier 1
Legal 500 in Commercial, corporate and M&A

Woman Leader
IFLR1000, 2021

Iberian Lawyer, 2017 e 2018

The most active M&A lawyers by number of deals in Spain
Jornal Expansión, 2015

Forty under 40 Award
Iberian Lawyer, 2013