The suspension, as an interim measure and ex nunc, of the effects of the termination of a contract, concluded between the public electricity company and a company before the Member State’s accession to the European Communities, granting that company a preferential electricity tariff, by a national court ruling in interlocutory proceedings, thus reinstating the application of that tariff during a specific period, had the effect of altering the time limits of application of that tariff, as agreed in the contract, and therefore the time limits of the aid scheme, as authorised by the Commission. The first order for interim measures must, consequently, be regarded as constituting alteration of existing aid.

In those circumstances, the extension of the duration of existing aid must be considered to be an alteration of existing aid and therefore, in accordance with Article 1(c) of Regulation No 659/1999, constitutes new aid.

The evaluation, by the Commission, of the compatibility of aid with the internal market is based on the assessment of the economic data and of the circumstances on the market at issue at the date on which the Commission makes its decision and takes into account, in particular, the period over which the grant of that aid is provided for. Consequently, the period of validity of existing aid is a factor likely to influence the evaluation, by the Commission, of the compatibility of that aid with the internal market.

Article 4(1) of Regulation No 794/2004 implementing Regulation No 659/1999 provides that, ‘for the purposes of Article 1(c) [of Regulation No 659/1999 laying down detailed rules for the application of Article 108 TFEU], an alteration to existing aid shall mean any change, other than modifications of a purely formal or administrative nature which cannot affect the evaluation of the compatibility of the aid measure with the [internal] market’.

The application of the State aid rules is based on a duty of sincere cooperation between the national courts, on the one hand, and the Commission and the European Union courts, on the other, in the context of which each acts on the basis of the role assigned to it by the FEU Treaty. In the context of that cooperation, national courts must take all the measures, whether general or specific, necessary to ensure fulfilment of the obligations under EU law and must refrain from those that may jeopardise the attainment of the objectives of the Treaty, as follows from Article 4(3) TEU. Accordingly, national courts must, in particular, refrain from taking decisions that conflict with a decision of the Commission.

Furthermore, it is for the national courts to verify whether the detailed arrangements for the implementation of an aid regime have been amended and, if it were to transpire that any amendments had had the effect of extending the scope of the regime, it could be necessary to consider that the aid was new, with the consequence that the notification procedure set out in Article 108(3) TFEU would be applicable.

Accordingly, a national court, ruling in interlocutory proceedings, seised of a dispute relating to a contract must notify to the Commission, in accordance with Article 108(3) TFEU, all measures which affect the interpretation and implementation of that contract that may have an impact on the functioning of the internal market, on competition or simply on the actual duration, over a specific period, of aid which continues to exist.

Indeed, to make it possible for national courts hearing an application for interim measures to escape the obligations incumbent upon them in the context of the control of State aids introduced by Articles 107 and 108 TFEU would lead those courts to disregard the limits of their own jurisdiction, intended to guarantee the observance of EU State aid law, and also to infringe their duty of sincere cooperation with the institutions of the Union and would, therefore, undeniably prejudice the effectiveness of those articles.

(see paras 105-108)