87The concept of a concerted practice refers to a form of coordination between undertakings which, without being taken to the stage where an agreement properly so-called has been concluded, knowingly substitutes for the risks of competition practical cooperation between them (Case C-49/92 PCommission v Anic Partecipazioni [1999] ECR I-4125, paragraph 115, and Hüls v Commission, paragraph 55 above, paragraph 158).