He led and participated in merger and acquisition transactions of important companies belonging to different sectors, including manufacturing and distribution, hotel trade, oil and gas, mining, financial services, digital economy, among others.

He has participated in a number of landmark tax disputes in Argentina, including cross-border transfer price litigations.

Since 2007 he has acted as Tax Expert Witness in domestic and international arbitration processes within the scope of the ICC, the ICSID, and the CEMA.

He was a founding partner of Negri, Teijeiro & Incera Law Firm and of Teijeiro & Ballone Abogados Law Firm. Previously, he worked as an associate at Klein & Mairal Law Firm in Buenos Aires and Caplin & Drysdale in Washington D.C.

He is a member of IFA General Council and was president of IFA Latin-American Region and of the Argentine Association of Taxation Studies (AAEF). He is also a member of the American Bar Association, the International Union of Lawyers, the Institute for International Taxation, and the Bar Association of the City of Buenos Aires.

He has taught in different universities and professional organizations in the United States, Mexico, Spain, and Argentina, among others. He has participated in several conferences and seminars in Argentina and abroad organized by IFA, Harvard Law School, IBA, and the AAEF, among others, as organizer and speaker.

He is the author of books and tax articles published in several languages and is a regular contributor to important forums and blogs on taxation.