The Department of Transportation and Infrastructure says it wants to find a developer who will buy the property and preserves the historic significance of the building.
The project has been expanded to include space that would be leased for government offices and for as many as three local non-profit organizations who want to become tenants with the city's support.
Transportation and Infrastructure Minister Claude Williams says expanding the scope of the project will help a developer make plans for the project.
The government wants a mixed-use for the 77-year-old building that could include space for arts and culture, residential, retail and commercial uses.
The building sits on 2.8 hectares of land in the city's heritage preservation area.
Proposals will be accepted until Nov. 7.