Article 3d 3.

The Commission is empowered to adopt delegated acts in accordance with Article 23 to supplement this Directive concerning the detailed arrangements for the auctioning by Member States of aviation allowances in accordance with paragraphs 1 and 1a of this Article, including the detailed arrangements for the auctioning which are necessary for the transfer of a share of revenue from such auctioning to the general budget of the Union as own resources in accordance with Article 311, third paragraph, of the Treaty on the Functioning of the European Union (TFEU). The quantity of allowances to be auctioned in each period by each Member State shall be proportionate to its share of the total attributed aviation emissions for all Member States for the reference year reported pursuant to Article 14(3) and verified pursuant to Article 15. For each period referred to in Article 13, the reference year shall be the calendar year ending 24 months before the start of the period to which the auction relates. The delegated acts shall ensure that the principles set out in the first subparagraph of Article 10(4) are respected.