Mondelez International said yesterday its ''global real estate partner'' CBRE was handling the sale.
It is understood the site will go on the market early next year. The factory closes in March.
A Mondelez spokesman said the multinational aimed to find a buyer whose plans would benefit Dunedin.
''We're confident anyone interested in purchasing a once-in-a-generation landmark city block in the heart of Dunedin's tourist precinct will have some really exciting plans for its development.
''As we've said since March, we hope to be able to find a buyer that will use the site in a way that benefits the local community.''
The site is on four separate titles.
''We're flexible when it comes to selling the site as one lot or separate titles and will wait to see the level of interest from potential purchasers,'' the Mondelez spokesman said.
Dunedin Mayor Dave Cull did not have a strong opinion about the future of the site.
But he said speculation it could be used to build the new Dunedin Hospital meant the Ministry of Health would probably take an interest in the sale.
''My impression is Mondelez would want the best outcome for the community.''
Mondelez was staying in part of the site in the revamped Cadbury World, so it had a direct interest in the site's future, Mr Cull said.
A source close to the rebuild previously told the Otago Daily Times the factory site was not suitable for a hospital, but it is unclear if that view is shared by the Ministry of Health.
Health Minister David Clark said last week he hoped to have something to say about the hospital site ''before Christmas''.
Yesterday, his spokeswoman said it was too soon to comment but ''progress is being made''.
She did not respond to questions about the Cadbury site.
