1. The auction clearing price shall be determined upon closure of the bidding window.
2. An auction platform shall sort bids submitted to it in the order of the price bid. Where the price of several bids is the same, these bids shall be sorted through a random selection according to an algorithm determined by the auction platform before the auction.
The volumes bid shall be added up, starting with the highest bid price. The price of the bid at which the sum of the volumes bid matches or exceeds the volume of allowances auctioned shall be the auction clearing price.
3. All bids making up the sum of the volumes bid determined pursuant to paragraph 2 shall be allocated at the auction clearing price.
4. Where the total volume of successful bids determined pursuant to paragraph 2 exceeds the volume of auctioned allowances, the remaining volume of the auctioned allowances shall be allocated to the bidder that has submitted the last bid making up the sum of the volumes bid.
5. Where the total volume of bids sorted pursuant to paragraph 2 falls short of the volume of auctioned allowances, the auction platform shall cancel the auction.
6. Where the auction clearing price is significantly under the price on the secondary market prevailing during and immediately before the bidding window when taking into account the short term volatility of the price of allowances over a defined period preceding the auction, the auction platform shall cancel the auction.
7. Before an auction is started, the auction platform shall determine the methodology for the application of paragraph 6, after consulting the auction monitor and obtaining its opinion thereon and notifying the competent national authorities referred to in Article 56. The auction platform concerned shall take the utmost account of the auction monitor's opinion.
In between two bidding windows on the same auction platform, the auction platform concerned may modify the methodology after having consulted the auction monitor and notified the competent national authorities referred to in Article 56.
8. Where an auction is cancelled pursuant to paragraphs 5 or 6, the auctioned volume shall be distributed evenly over the next auctions scheduled on the same auction platform.
In case of allowances covered by Chapter III of Directive 2003/87/EC the volume to be auctioned shall be distributed evenly over the next four scheduled auctions.
In case of allowances covered by Chapter II of Directive 2003/87/EC the volume to be auctioned shall be distributed evenly over the next two scheduled auctions.