North Lanarkshire chief executive Andrew Cowe said any suggestion David McKendrick, who will be 65 in September 1996, was not the best candidate for director of social work was 'ageist'.
He was appointed by a panel which included two councillors who work with him in the social work department at Strathclyde RC.
Mr Cowe said his is not the only unitary where there has been a connection between candidates and interviewers: 'The situation has been repeated throughout Scotland.'
North Lanarkshire has completed its director appointments and is now choosing deputes. Mr Cowe said the latest round of interviews would follow Staff Commission guidance.
An applicant for Mr McKendrick's post, Ian Gilmour, complained that the appointments procedure was unfair. Mr Gilmour also works in Strathclyde social work department, as depute director.
He complained to the Staff Commission that being interviewed by members of his staff prejudiced his candidacy.
Mark Irvine, Unison head of local government in Scotland, has written to the Staff Commission urging it to intervene.