CIRE, a global network of 10,000 real estate agents, was founded by the 250-year-old British auction house in 1995 but was sold to proptech firm @properties in 2021. The brokerage got to hang onto its famous brand name and the two firms remain loosely partnered, according to an announcement of the acquisition. The 156 Fifth deal comes amid a larger expansion for the local Christie's affiliate, according to Brett Forman, managing director of Christie's International Real Estate Group for Manhattan. "This new office will enable our team to further strengthen our capabilities across both the city and state of New York," Forman said in a statement. And the local affiliate isn't the only Christie's signing Manhattan deals this week. The famed auction house signed a 20-year renewal for its 400,000-square-foot space at 20 Rockefeller Plaza.