U.C.C. § 2-328. Sale by Auction.

Facts

(1) In a sale by auction, if goods are put up in lots each lot is the subject of a separate sale.
(2) A sale by auction is complete when the auctioneer so announces by the fall of the hammer or in other customary manner. If a bid is made during the process of completing the sale but before a prior bid is accepted, the auctioneer has discretion to reopen the bidding or to declare the goods sold under the prior bid.
(3) A sale by auction is subject to the seller’s right to withdraw the goods unless at the time the goods are put up or during the course of the auction it is announced in express terms that the right to withdraw the goods is not reserved. In an auction in which the right to withdraw the goods is reserved, the auctioneer may withdraw the goods at any time until completion of the sale is announced by the auctioneer. In an auction in which the right to withdraw the goods is not reserved, after the auctioneer calls for bids on an article or lot, the article or lot may not be withdrawn unless no bid is made within a reasonable time. In either case a bidder may retract a bid until the auctioneer's announcement of completion of the sale, but a bidder's retraction does not revive any previous bid.