The Ilot Voyageur project is considered a symbol of mismanagement of public funds.
The skeletal downtown structure has been untouched since 2007, when cost overruns put a stop to the ambitious project and nearly bankrupted the Universite du Quebec a Montreal in the process.
The university had planned to build student housing on the upper floors of the site.
The Parti Quebecois government has sold the building to B.C.-based real-estate developer Aquilini.
The transaction is valued at $45.5 million and Aquilini plans to invest more than $150 million in a project to build 700 condos and apartments.
The downtown site is next to the intercity bus terminal and also to Berri-UQAM station, the central hub connecting Montreal's main subway lines.
The government's real-estate arm took possession of the abandoned project in 2010 and put it up for sale in 2012.
Premier Pauline Marois lamented the $225 million lost in the project, which is frequently cited as Exhibit A in past mismanagement of public funds.
The bus station will be run by the metropolitan transit agency and there is a plan to build some student housing on a separate site.