Expressions of interest are being sought from the private sector for the Fort George site in Londonderry.
The 15-acre site owned by the Department for Communities (DfC) has received outline planning permission.
Preliminary work is taking place to get the former army base ready for a change of use, with completion expected by the end of the year.
DfC has appointed the property consultants Lisney to manage the process with expressions of interest sought by November 9.
Damian Mulholland, director of the DfC's North West Development Office, said its location and the proximity of Catalyst Inc's north west site were all advantages. "With the remediation of Fort George under way, the department is now moving to test the nature and scale of market interest in the site.
"Given its strategic location adjacent to the A2, for which DfI has published road upgrade proposals, the presence of Catalyst Inc, which has sought planning permission for a second building, and an impressive river frontage, we believe the site is ideally placed to deliver lasting social and economic benefits for the city.
"We look forward to receiving suitably ambitious proposals to realise that potential."
In the case of a positive response, the department will then proceed with a full marketing exercise to select a purchaser. The department said creation of jobs was a key priority and proposals received will be assessed against that and other criteria.
Andrew Gawley, director, Lisney said: "Planning proposals for this 6.2-hectare site include over 885,000 sq ft of gross floor space for mixed use facilities, making it a supremely unique opportunity.
"The team at Lisney in Belfast is delighted to partner with Department for Communities on this very exciting project that will ultimately play a huge role in the regeneration of the area.
"At this initial stage, we are certainly expecting expressions of interest from potential investors within the UK and Ireland, but I would also expect enquiries from further afield."