Laing O’Rourke will work on the first phase building under a contract thought to be worth around £45m.
RGU wants to create a new base for engineering, architecture and the arts and sciences at an eight-acre site next to its current Aberdeen campus.
The planned £170m development will ultimately see all of the University’s academic activities located at the Garthdee Campus in a new 340,000 sq ft complex.
This will involve building a new main entrance, student plaza and landmark library tower.
The first phase involves relocating all city centre academic provision to Garthdee in time for the 2012 academic year.