Montreal city council has approved a controversial zoning change that would pave the way for an historic former convent to be converted into condominiums.

The rezoning bylaw was passed at City Hall following a marathon debate.

The building, located in Outremont at the foot of Mount Royal, is currently owned by the University of Montreal.

"It will not fall to abandon. It will be there, it will be vibrant, it will be active," said Montreal executive committee member Alan De Sousa.

Opposition parties and heritage groups did not want to see the 85-year-old convent turned into luxury condos.

The problem is that the university and the city do not have the $135 million that would be needed to maintain the building.

A developer wants to gut the building and build 135 luxury condos inside the facade.

Controversial firm

Opposition parties also have major problems with the buyer, Construction Frank Catania & Associates Inc.

"I would prefer that it would be a contractor without any suspicion," said Projet Montreal leader Richard Bergeron.

The head of the construction firm, Paolo Catania, has been charged with uttering death threats, extortion and criminal harassment.

Catania is also a partner with the city in the controversial Faubourg Contrecoeur housing project, which was investigated last year by the city's Auditor General.

The project triggered an internal investigation because Catania's company bought the land from the city for millions of dollars less than what it was worth.

Access to mountain

Dinu Bumbaru of Heritage Montreal said he wonders how the condo project would affect public access to the part of Mount Royal in question.

"Is the ground going to be gradually surrounded by fences and walls? I mean, we don't want to cut the mountain into pieces that we are forbidden access to," Bumbaru said.

But De Sousa said that won't be the case.

"This is no new encroachment on the mountain, this is no disappearance of green space," he said.