It is not the notification of a measure that determines the legal regime ratione temporis applicable to that measure, but the nature of the measure, being either existing aid, not subject to the principle of compulsory notification, or new aid, subject to compulsory notification and to a prohibition on implementing the measure pursuant to Article 88(3) EC. The notification merely constitutes a procedural instrument, intended to allow the Commission to verify the measure in question, and cannot have the effect of creating law.

By adopting rules of conduct and announcing by publishing them that it will henceforth apply them to the cases to which they relate, the Commission imposes a limit on the exercise of its own discretion and cannot depart from those rules under pain of being found, where appropriate, to be in breach of the general principles of law, such as equal treatment or the protection of legitimate expectations, unless it can provide reasons justifying its departure from its own rules, in view of those same principles. In the specific field of State aid, the Commission may adopt guidelines on the exercise of its powers of assessment and, in so far as those guidelines do not contradict Treaty rules, the policy rules which they contain are to be followed by that institution.

In State aid matters, bearing in mind that State guarantees constitute a type of aid awarded in a form other than a grant, and pursuant to the first subparagraph of Article 2(3) of Regulation No 69/2001 concerning the application of Articles 87 and 88 of the EC Treaty to de minimis aid, the aid element contained in those guarantees must be calculated. It is the amount of that aid element that determines whether or not the guarantees fall within the scope of application of the de minimis rule applicable at the time they were awarded.

The Commission outlined its approach to calculating the aid element of a guarantee in its Notice on the application of Articles 87 and 88 of the EC Treaty to State aid in the form of guarantees (‘the 2000 Notice on guarantees’).

The 2000 Notice on guarantees forms part of the legal framework within which the Commission has to assess the guarantees at issue and, in particular, the use by the national authorities of a flat rate of 0.5% of the guaranteed amount to determine the aid element of the guarantees at issue. Non-application of that notice cannot be justified on the ground that the aid in question does not exceed the de minimis threshold. The conclusion that the guarantees at issue fall within the de minimis regime presupposes, upstream, an examination of the legality of the use of the flat rate referred to above in order to conclude that the aid element of those guarantees falls below the de minimis ceiling.

It follows that failure by the Commission to examine the legality of the use of a rate of 0.5% of the guaranteed amount to determine the aid element of the guarantees at issue within the context of the 2000 Notice on guarantees constitutes an indication that there were serious difficulties in knowing whether the guarantees at issue could be classed as de minimis aid. The existence of such difficulties must lead the Commission to initiate the formal examination procedure.

(see paras 157, 158, 167-169, 186)