He was awarded, on the base of merit, two scholarships: one from the University of Bologna and another one from the National Research Council (C.N.R.)
In 2007 and 2008, Prof. Marrella has served as vice-Director of the Harvard University-Venice program where he taught International Business Law.
He was formerly Adjunct Professor of International Business Law at the IHEAL (Institute for Advanced Studies on Latin America) of the University of Paris III: Sorbonne Nouvelle and lecturer at the Paris Institute of Comparative Law (Panthéon-Assas University).
[citation needed] Marrella taught "The international Arbitral Process", Vanderbilt University Law School; International Business Transactions (Widener International Law Summer Institute); Derecho del comercio internacional (taught in Spanish) in the Universidad Interamericana de Puerto Rico.
Among his writings there are: He is also the author of more than 35 articles published in national and international peer-reviewed Law Journals.