Brussels, 17/01/2000 (Agence Europe) - On Tuesday, the European Commission is expected to adopt a preliminary draft regulation on horizontal agreements concluded between competitive firms. Presented in the context of the major revision of European competition rules in progress, the document will serve as a basis for discussion between Member States, before the Commission presents a formal project. In accordance with the model regulation concerning vertical restrictions, recently adopted by the Commission, the regulation on horizontal agreements will define the conditions for granting block exemption and the types of agreements that may benefit as a result. As in the case of vertical restrictions, the companies representing less than 30% of the market most of all benefit from block exemption.