In light of a changing corporate culture, the European institutions have been faced with interpretative questions that were not contemplated by the original statutory schemes of European antitrust enforcement. One of these issues è ' the application of the European antitrust provisions to the relationship between a parent and a subsidiary company è ' has led the Commission and the ECJ to develop the concept è -single economic entityè -- for the purpose of applying the antitrust provisions to corporate groups. However, both the Commission and the Court have regularly refrained from a detailed analysis of the specific circumstances of consideration for this legal concept; and as a result the assessment of legally independent but economically affiliated companies is one of the most contentiously debated issues of European antitrust law.