The Paper Exchange is a £45m development of 200,000 sq ft of office space in Belfast city centre.
Building work starts this week and more than 100 jobs are expected to be created during its construction.
Draperstown-based Heron Bros was awarded the contract by developer Wirefox.
The 11-storey building at 43-63 Chichester Street is due for completion by December 2021.
The project, designed by Belfast-based Todd Architects, will be built to the BREEAM Excellent sustainability standard.
Heron Bros deputy managing director Martin O’Kane said: “Few commercial developments can truly earn the title of ‘landmark building’ but The Paper Exchange is an exciting exception and we’re proud to have been chosen to oversee its construction and to deliver on the exacting design requirements of this iconic, transformative project for Belfast and Northern Ireland.”