Council Regulation (EC) No 139/2004 on the control of concentrations between undertakings, which replaced Council Regulation (EC) No 4064/89 (as amended) for transactions after 1 May 2004. The EUMR requires compulsory and exclusive (one-stop shop) prior notification to the European Commission of mergers, acquisitions and certain joint ventures that involve a change of control and meet certain turnover thresholds.