Extensive foreign economic relations can be replaced by local hubs of business cooperation. The Hanseatic League of New Time can be such an example. The rulemaking process shifts from states to non-governmental organizations in international private law. The authors analyze what the science of civil law can offer today for the development of sustainable business cooperation between entrepreneurs of the New Hanseatic League. Research methods. The authors explore the concepts of "sustainable business cooperation between entrepreneurs of the Hanseatic League" and "the institution of contractual regulation of business relations between entrepreneurs of different nationalities". Based on these concepts, the authors analyze the possibilities of the Hanseatic League to influence the development of this institution. According to the results of the analysis, the authors make recommendations on the formation of standards for new business practices of the Hanseatic League. Results. The authors propose a scientific definition of the concept of "sustainable business cooperation between entrepreneurs of the New Hanseatic League". The authors conclude that the institution of contractual regulation of foreign economic relations includes not only formal norms but also norms of other levels of regulation. One of these levels is the level of entrepreneurs themselves. The authors recommend the New Hanseatic League to form new standards of contractual practice, using the experience of researchers and practitioners of international private law, lex mercatoria law and comparative law. These recommendations include the use of new technologies in the standards of business practice of concluding and executing contracts, such as distributed registry technologies, electronic documents and other data. Keywords-the Hanseatic League; sustainable business cooperation; the institution of contractual regulation; legal means of ensuring sustainable business relations of the New Hanseatic League I. Economic research pays great attention to the sustainable development of economic systems, although this term does not have a uniform understanding. For example, in international organizations, "sustainable development" means meeting the needs of the current generation without threatening the ability of future generations to meet their own