The BBC is on the hunt for a new Casualty and Holby City showrunner as Johnathan Young looks set to leave the broadcaster.

The BBC in-house drama unit has advertised for the role as Young’s two-year fixed-term contract is due to come to an end.

Young replaced Belinda Campbell on BBC1’s medical dramas in February 2011 after six years at FremantleMedia UK heading up long-running series The Bill. He was also responsible for dramas including BBC2’s The Sinking of the Laconia.

It is not known whether Young will re-apply for the post, which is based in Wales and reports into Kate Harwood, BBC head of drama for England.

Young returned Casualty to its roots of having a different story or accident every week last year. The programme averaged 5.48m (21.72%) in 2012, a drop on the 5.79m (22.65%) it recorded the year before.

Holby City’s audience has fallen more markedly year-on-year. In 2012 it averaged 4.83m (19.58%) viewers on BBC1, a near 13% decline on 2011’s 5.54m (22.49%).