113As regards a proceeding pursuant to Article 81 EC, it follows from the case-law that the administrative procedure before the Commission is divided into two distinct and successive stages, each having its own internal logic, namely a preliminary investigation stage and an inter partes stage. The preliminary investigation stage, covering the period up to notification of the statement of objections, is intended to enable the Commission to gather all the relevant evidence confirming that there has or has not been an infringement of the competition rules and to adopt an initial position on the course which the procedure is to follow. The inter partes stage, which covers the period from notification of the statement of objections to adoption of the final decision, must enable the Commission to reach a final decision on the alleged infringement (see, inter alia, to that effect, Joined Cases C-238/99 P, C-244/99 P, C-245/99 P, C-247/99 P, C-250/99 P to C-252/99 P and C-254/99 PLimburgse Vinyl Maatschappij and Others v Commission [2002] ECR I-8375, paragraphs 181 to 183, and Prym and Prym Consumer v Commission, paragraph 27).