Marketing company Amaze has signed a lease on 16,500 sq ft at Ask Developments' One First Street in Manchester.
Amaze is relocating 120 staff from Chapel Studios in Castlefield nearby and will move in to First Street this weekend.
Manchester City Council occupies 140,000 sq ft in the building as the town hall complex is being refurbished. The Amaze deal means the building is now 90% let with 22,500 sq ft available to let.
Julian Stott, development executive at Ask Developments, said: "The directors chose Number One from a shortlist of six options available in and around the city centre where the quality of the public realm really enhances First Street for companies who want something more than standard office space."
James Evans at Savills advised Ask Developments. David Laws at Matthew & Goodman advised Amaze.