Mr. Zambrano Abrego joined Santos Elizondo in 1998 and has been a partner since 2009. For almost 20 years, his practice has focused mainly on acting as (i) general counsel, with emphasis on the solution of complex legal, corporate, equity and regulatory problems and (ii) advisor in diverse commercial and financing transactions involving domestic and/or foreign investors, including the design, negotiation and implementation of structures for the acquisition or sale, development and financing of projects, in matters of energy, administrative and public finance law, as well as in complex negotiations before federal, state and municipal authorities. His practice has been distinguished by the representation of important national and international groups as well as families in their operations in Mexico and by the provision of creative solutions to all types of problems that afflict clients.

Some of the clients he has represented are Altregy Consulting, Askoll, Capital Natural, Fitch Ratings, Global Telesourcing, Global Finishing Solutions, Holland, Iconn, Infosys, Infrisa, Inusa, Kia, Kloeckner Metals, Merbain Consulting, Packsys, Plastypel, Resguardo Asset Management and has participated as legal counsel in the following significant transactions, among others:

Process of acquisition or sale of businesses in transactions up to UScy$150 million.
Establishment of companies with foreign investment up to UScy$1,500 million.
Negotiation of various contracts (supply, financing, joint ventures, trusts, shareholder agreements, guarantee mechanisms, leases) for amounts up to US$250 million.
Complex dispute resolution between Mexican and/or foreign parties.

Mario obtained his law degree in 1997 from the Law School of the Instituto Tecnológico y de Estudios Superiores de Monterrey. In 2002 he graduated with a Master of Laws degree (with emphasis in international and corporate matters) from Harvard University in Cambridge, MA. Additionally, he has completed several refresher courses in commercial, administrative, banking, securities and financial matters.

He has participated as a member of the board of directors of several charities such as EFFETA, COMUNIDAR and the AFP (Association of Fundraising Professionals), as well as organizations such as Coparmex, Club Harvard de Monterrey and Club Rotario Monterrey Metropolitano.