Atherton joins AE from Carnival UK, where he most recently served as a regional sales manager with Cunard.
Prior to his post with Cunard, he was part of P&O Cruises' trade sales team, and has previously held roles in contact centre operations and guest services.
He started his career in travel as a baggage handler at Southampton docks, which AE said gave him "a deep understanding of the cruise industry from the ground up".
Atherton, who will be based in Southampton, will be tasked with strengthening the line's relationships with agents, supporting commercial growth and driving sales performance.
