Serle, who will report to broadcast sales director Karen Stacey, will manage all aspects of radio sales while driving Emap Advertising's commercial strategy.
Before taking on the management of West Midlands-based rock station Kerrang!, he was commercial director on Emap's Hallam FM and Magic. Prior to this he worked at GWR in Bristol and independent radio specialists Radio Works.
The role of radio sales director is a new position, differing slightly from Daisley's head of agency sales (radio). More changes to the advertising structure are expected to follow.
Stacey today praised Serle's "drive and enthusiasm", saying: "Understanding what clients want from advertising partners and how to re-engage our agency customers with the radio medium will be high on his list of priorities."
Serle takes up his new role on 19 March.