This working paper addresses the theme of the transformation of private law considering in particular the concepts of autonomy, competition and regulation in European private law. The contributions included in this working paper present some of the outcomes of the research done during the fourth year of the project on European Regulatory Private law which was presented and discussed with external guests at the fourth annual workshop of the project on 18 and 19 June 2015 at the European University Institute in Florence. After having discussed in the three prior annual meetings the parameters around which European regulatory private law is organized, the fourth workshop focused on the key framing proposition of the investigation, i.e. the transformation of private law from autonomy to functionalism in competition and regulation. In the first part of the working paper, the central concepts of the suggested transformation will be introduced and placed in the theoretical framework of the research project, addressing the issue of the drivers of the transformation, of autonomy and regulation, and of competition. In the second part, the transformation is looked for in specific sectors of European regulatory private law, i.e. telecommunication, energy, standardization, and the financial sector highlighting the aspects that may illustrate the posited transformation of the operative private law in these areas