Order Reprints Print Article Originally asking C$12.9 million, the home was the most expensive condominium ever listed in Montreal. SOTHEBY'S INTERNATIONAL REALTY QUEBEC Text size A 5,300-square-foot unit at the Ritz-Carlton Residences in Montreal’s downtown quarter known as Golden Square Mile, officially sold for C$11 million (US$8.636 million) this week. Originally asking C$12.9 million, it was the most expensive condominium ever listed in Montreal, according to listing records, and was the priciest condo to sell in Quebec. The seller, Sophie Desmarais, is the daughter of the late Canadian financier Paul Desmarais, according to records. Her family controls Power Corp. of Canada, a multibillion-dollar holding company.