Developer Argent and Manchester City Council officially launched The Hive on Lever Street in Manchester's Northern Quarter.
Oliver Butler, project manager at Argent, said: "We are very pleased to have launched The Hive with such a fantastic event. The building is now 40% let, with The Studio and the Arts Council England having already moved in."
Butler remains "extremely optimistic" about letting the rest of the office space after event specialist The Studio agreed to take 10,000 sq ft and Arts Council England had taken 20,000 sq ft.
At the event, the two towers, which make up The Hive, were divided into separate "moods" for guests to enjoy, with one symbolising "live" and the other "breathe".
The "live" aspect of the event included a programme of music by Band On The Wall and Manchester DJ, Mr Scruff.
The "breathe" tower gave invited guests the opportunity to enjoy soothing head and neck massages, whilst listening to music from the Manchester's Camarata, an organisation sponsored by Argent.
Manchester-based events company Ear to the Ground were hired for the launch night. David Norris, operations director, said: "We spend a lot of time working with developers who want to bring their schemes to life. Our experience in creating events and live activity means we have been able to help Argent to maximise full value from the launch and integrate the live strategy into the overall marketing campaign."
David Partridge, joint chief executive at Argent, added: "We wanted the organisations that we work with to be involved in the launch of The Hive. Not only are they situated within close proximity, they also embody the creativity of The Hive as a building and its dedication to this unique part of the City."
Colliers CRE and Daniel Harris & Co are the letting agents for The Hive.