Global engineers and consultants Sinclair Knight Merz has taken a further 5,000 sq ft at BAM Properties' Metro office development at Salford Quays.
The letting completes the merger of SKM's two regional offices in Manchester city centre and Salford Quays.
Paul Smith, BAM Properties' northern development manager, said: "Metro has met BAM's original concept of creating a highly efficient, sustainable office environment in which businesses can thrive, exemplified by this latest letting. SKM has been able not only to expand its occupational requirement but will be operating its entire North West operation in one building on a single floor-plate".
There are now only two 17,800 sq ft floors to let at Metro.
Joint letting agents Canning O'Neill and CBRE acted for BAM Properties.