Economic development of participants in international trade is a naturally goal which leads to the creation of complex structures, with or without legal personality that tend to dominate the market. A dominant position can only be the result of successful actions that have created a prosperous position, customers for the company with such a position. The legislature could not conceive that the professionals in trade to remain in positions of approximately equal share without distinction in terms of market domination. Such a picture of market competition is more compatible with a centralized economy, an economy in which resources and operations are distributed or arranged by a national authority. These structures, the result of economic concentration, can have different shapes and sizes, their diversity being given by each national legal system, but are characterized by certain traits, peculiarities which we will analyse in our study. In Romanian law, as in the French-inspired national systems, is recognised the existence of the Economic Interest Group (EIG) which is outlined at the European level as a European Economic Interest Group. Joint venture, all French-inspired, is not a new institution from law point of view, being taken from the old commercial code, but it is applied frequently in the market, being a simple operation aimed to realise a business partnerships to achieve in joint activities. Our approach will extend to other manifestations of economic concentration known in international trade, in particular on those existing at European level, referring here to the English and German law. (C) 2016 Published by Future Academy www.FutureAcademy.org.uk