Are declaratory actions in cartel damages proceedings still admissible?

During the quarterly Frankfurt meeting of the Studienvereinigung Kartellrecht, an association of German-speaking competition law attorneys, Mr. Hristov gave a presentation on recent judicial developments with regard to the admissibility of declaratory actions in cartel damages proceedings. The presentation was centered around a recent decision by the Federal Supreme Court (BGH of June 12, 2018 - KZR 56/16) and explored how this decision fits within the legal framework of established civil procedural law and the changes it brings for future claimants.