Coordination between undertakings which, without having reached the stage of concluding a formal agreement, have knowingly substi- tuted practical cooperation for the risks of competition. A concerted practice can be constituted by direct or indirect contact between firms whose intention or effect is either to influence the conduct of the market or to disclose intended future behaviour to competitors.
Source: Glossary of terms used in EU competition policy, Antitrust and control of concentrations, European Commission, 2002