The paper is focused on the introduction and operation of a novel model of EU-induced, structure of governance networks - composed of public administration, business and civil society actors. It takes up a case of institutional structures to manage EU structural funds in Poland. In particular, the role of social partners, i.e. representatives of non-governmental organizations in the European Regional Development Fund-related region-level and nation-level steering and monitoring committees is analyzed. Following a brief exposition of regionalization principles, arrangement for regional development policy in Poland and changes induced by the country's accession to the EU, legal and institutional frameworks for the inclusion of social partners in the committees responsible for the programming, management and evaluation of the European Regional Development Fund are scrutinized. Empirical evidence of social partners' participation in the proceedings of such selected committees is introduced and analyzed. Opportunities, challenges and dilemmas of civil society actors faced with new modes of governance are discussed.