Stanley Gibbons Group has sold its lease on Ely House in London, formerly home to the antiques dealership Mallett, along with an adjacent property for £2.5m. The company has also sublet “a substantial part” of Mallett’s New York premises. The contemporary art dealer Thaddaeus Ropac has confirmed that he has taken on the London leases for his first UK gallery, and plans to open in Spring 2017. Polly Robinson Gaer, previously at Pace, will head Ropac’s London operations. According to New York’s Commercial Observer newspaper, the fashion designer Stella McCartney has sublet Mallett’s 929 Madison Avenue premises.