Peter Derrick, director of finance at Surrey CC, will replace Bernard Harty next March. The corporation's city secretary, Tom Simmons, will assume Mr Harty's town clerk role. The two posts, which can be traced back 700 years, were merged for Mr Harty in 1996.
Mr Derrick acknowledged that his new job involved ceremonial and promotional duties beyond the remit of the normal finance director post.
He is also keen to be involved in planning for the new Greater London Authority. 'I want to play a part in the development of the financial structure for London government. There needs to be between the City and the London boroughs a clear agreement on the financial structure.'
Mr Derrick refused to discuss possible Corporation spending plans beyond saying: 'The Corporation has considerable financial strength which gives it a capacity to act greater than other local authorities.'