An auctioneer is a person employed to sell another person's property by auction. When carrying out the sale, an auctioneer is the seller's agent. After the sale, an auctioneer is empowered to act for the buyer and the seller for the purposes of completing the memorandum of sale.
Mercantile agents are persons to whom goods are entrusted by their owner so that the agent can deal with the goods on the owner's behalf. Mercantile agents therefore have the power to buy and sell such goods on behalf of their owners.