Atelier 16, which is unconnected to either Atelier One or Atelier 10, has now combined its knowledge of the private and commercial sectors with NTA Projects' experience in social housing.
The new company, which is to be called NTA Projects Ltd, will continue to work from Atelier 16's existing offices in Islington.
The new company is already involved in a number of projects in Nigeria, Kenya, Guinea, Pakistan and Romania, where it has an affiliated office - Arlthop SRL.
A spokesman for the company said: 'The re-organisation in our structure is part of a planned development and will support, complement and enhance the services we can offer.
'We look forward to continuing our existing relationships and to develop new areas and opportunities. Our objective is to contribute to the development process with a perceptive interpretation of our clients' needs and requirements.
'Our philosophy is structured by both pragmatic and creative points of reference,' he added.