Division 4: Application of the Commission Notice on the Non-imposition or Reduction of Fines in Cartel Cases (the Leniency Notice): significant reduction in the amount of the fine - Commission Decision of 27 November 2002 relating to proceedings under Article 81 of the EC Treaty against BPB PLC, Gebrüder Knauf Westdeutsche Gipswerke KG, Société Lafarge SA and Gyproc Benelux NV (Case No COMP/E-1/37.152 — Plasterboard) (notified under document number C(2002) 4570) (Only the English, French, German and Dutch versions are authentic) (2005/471/EC)