On 10 April 2014, the Court of Justice handed down two judgments concerning the gas insulated switchgear cartel (Joint cases C-231/11, C-232/11 P and C-233/11 P European Commission v Siemens AG Österreich and Others and Siemens Transmission & Distribution Ltd and Others v European Commission; Joint cases C-247/11 P and C-253/11 P  Areva SA and Others and Alstom Grid AG and Others v Commission).

In Siemens, the Court of Justice stated that although the Commission has the power to hold a number of companies jointly and severally liable for the payment of a fine if they form part of the same undertaking, (see Article 23 of Regulation No 1/2003), it cannot determine the shares of the fines to be paid by those held jointly and severally liable from the perspective of their internal relationships.

The Court firstly confirmed the General Court's ("GC") consideration that where several legal persons may be held responsible for participating in an infringement committed by one and the same undertaking for the purposes of competition law, they must be regarded as jointly and severally liable for that infringement. The objective of joint and several liability is therefore to provide the Commission with an additional legal device to strengthen the effectiveness of the action taken by it for the recovery of fines imposed for anti-competitive behavior.

Nevertheless, the Court points out that the determination of the shares that each of the involved entities must pay does not pursue this objective considering that the Commission loses its interest once it has obtained the payment of the fine in full by one or more of those held liable. The determination of the internal relationship of those held jointly and severally liable for the payment of the fine and consequently the determination of the respective shares that they will be required to pay, is a contentious issue that should be resolved by the national courts by applying the national law applicable to the dispute, in a manner consistent with EU law. Therefore, the Court concludes that the GC had erred in law in finding that it is exclusively for the Commission in exercising its power to impose fines, to determine the respective shares of the various companies of the fines imposed on them jointly and severally, insofar as they formed part of the same undertaking, and that such task could not be left to the national courts.

In the Areva/Alstom judgment, the Court of Justice concluded that the GC had wrongly applied the rules governing joint and several liability for the payments of fines. The GC had confirmed the decision in which the Commission had imposed de facto joint and several liability on Alstom and Areva, two successive parent companies of a subsidiary who had participated in the cartel, even though those parent companies had never constituted an economic unit between them.

Despite the fact that there were no corporate ties between Areva and Alstom, the joint and several liability established between the subsidiary and the successive parent companies, would force one of them to pay the entire fine. Consequently, once the whole fine has been paid, the parent company would have to seek recovery from the other parent company by means of an action before a national court. According to the Court such a definition of joint and several liability is at odds with the principle that the penalty must be specific to the offender and the offence. The Court continues by pointing out that, although joint and several liability enables the Commission to reduce the risk of insolvency of one of the companies forming part of the same undertaking, it cannot be used to force one company to bear the risk of the insolvency of another company with which it has never formed part of the same undertaking. Moreover, since the contested decision did not enable the parent companies to ascertain precisely the amount of the fine they should pay in respect of the period during which they were held jointly and severally liable, the Court concluded that the principle of legal certainty had also been infringed.