Parent company Blue Ant Media made the decision it should not have capital tied up in real estate.
Blue Ant Media content production co-president Sam Sniderman said NHNZ had purchased the building in 2009 but felt a sale now was the right decision for the long-term future of the company.
"We are a content company and that is where we should be investing our capital.
"We operate in many countries across the world but we do not own real estate outside of Dunedin," he said.
The 3240sqm building housed 30 staff and it was hoped they could remain under a lease agreement with the buyer of the property, Mr Sniderman said.
"We hope that the building will be purchased by someone interested in, and supportive of, the long-term future of Dunedin."
It was "hard to say" what its value was, he said.
Tenders close on August 6.
