Birmingham property developer Court Collaboration is currently converting the former Bournville base, reputedly the birthplace of the Curly Wurly, into 79 apartments.
The £16 million redevelopment of Franklin House, to be rebranded 'The Franklin', includes four penthouses with internal courtyards and is due to be completed by next spring (see gallery above for new CGIs).
Court Collaboration founder and chief executive Anthony McCourt said: "Joining forces with Knight Frank to sell the properties in The Franklin made complete sense.
"This is a first for Bournville and Knight Frank's experience of this type of development, along with its outstanding reputation and presence, made it the ideal partner to help us transform this redundant building into people's new homes."
Stuart Eustace, sales manager at Knight Frank, added: "As the agents bringing The Franklin to market, we are excited to be involved with the rejuvenation of this former office building in one of the city's most desirable and established suburbs.
"We expect The Franklin to appeal to a broad spectrum of investors and owner occupiers alike. Interest in The Franklin is already strong and reservations have already been taken."