The article discusses the role of MNCs in the process of transformation of global regulation of trade and international economic relations system. The relevance of this study is determined by one of the key trends in the world economy and the system of international economic relations of the late XX — early XXI centuries — by the process of corporatization of the economic space. There is a desuverenization and corporatization of the national economies of the countries. This process is associated with the increasing dependence of national economies on MNCs and is accompanied by the deepening of the process of corporate globalization of the economic space. The system of economic relations of mega-regional partnerships is the subject of the research. The purpose of the study is to determine the role of MNCs in the process of transformation of global regulation of trade and international economic relations system. There are different methods of scientific knowledge used in the research: comparative-historical, as well as general scientific methods: abstraction, axiomatic method, analysis, induction. As a result of the study, the author identified the key trends in the world economy of the XX–XXI centuries: the corporatization of the economic space, coupled with the desovereignization of national economies. The main findings of the study are: first, the trend towards corporate globalization in the world economy; second, a qualitative changes in the form of organization of trade and economic relations: the transition from globalization to globalizing regionalism — an increase in the number of mega-regional trade agreements, such as the Trans-Pacific Partnership / Comprehensive and Progressive Agreement for Trans-Pacific Partnership, The EU-Canada Comprehensive Economic and Trade Agreement, The Regional Comprehensive Economic Partnership, etc.; third, the crucial role of MNCs in the transformation process of the global trade regulation system; fourth, qualitative changes in the form of relations between corporate sector and state. The results of the study can be used in further research on a given topic.