1. Before taking decisions as provided for in Articles 7, 8, 23 and Article 24(2), the Commission shall give the undertakings or associations of undertakings which are the subject of the proceedings conducted by the Commission the opportunity of being heard on the matters to which the Commission has taken objection. The Commission shall base its decisions only on objections on which the parties concerned have been able to comment. Complainants shall be associated closely with the proceedings.

2. The rights of defence of the parties concerned shall be fully respected in the proceedings. They shall be entitled to have access to the Commission's file, subject to the legitimate interest of undertakings in the protection of their business secrets. The right of access to the file shall not extend to confidential information and internal documents of the Commission or the competition authorities of the Member States. In particular, the right of access shall not extend to correspondence between the Commission and the competition authorities of the Member States, or between the latter, including documents drawn up pursuant to Articles 11 and 14. Nothing in this paragraph shall prevent the Commission from disclosing and using information necessary to prove an infringement.

3. If the Commission considers it necessary, it may also hear other natural or legal persons. Applications to be heard on the part of such persons shall, where they show a sufficient interest, be granted. The competition authorities of the Member States may also ask the Commission to hear other natural or legal persons.