The Regulations prohibits, as incompatible with the Common Market, all agreements between undertakings, decisions by associations of undertakings and concerted practices which may affect trade between Member States and have their object or effect the prevention, restriction and distortion of competition within the Common Market. More specifically, Article 19 (3) of the Regulations prohibits the following cartel conducts:

1. agreements fixing prices, which agreements hinder or prevent the sale or supply or purchase of goods or services between persons, or restrict the terms and conditions of sale or supply or purchase between persons, or restrict the terms and conditions of sale or supply or purchase between persons engaged in the sale of purchased goods or services;
2. collusive tendering and bid-rigging;
3. market or customer allocation agreements;
4. Allocation by quota as to sales and production;
5. Collective action to enforce arrangements;
6. Concerted refusal to supply goods or services to a potential purchaser, to purchase goods or services from a potential supplier; or
7. Collective denials of access to an arrangement or association which is crucial to competition