The part-completed 19-acre site, built around the remains of the city's Royal Infirmary and intended as a 'vibrant cosmopolitan new quarter' supporting 5000 jobs, was reported as sold to the Exemplar group in January 2012 for £65 million, but then came back onto the market.
Now one of the unsuccessful bidders then, Moorfield Group, has done a "multi-million pound" deal with owners Gladedale Capital, who acquired the site in 2005 from original developers Bank of Scotland, Taylor Woodrow and Kilmartin Property Group.
The development was valued at some £60m by Gladedale last year. Masterplanned by architect Norman Foster's practice, it was originally predicted to have an end value of up to £500m once all the apartments, grade A offices, hotel, leisure and retail space was built and occupied.
Office occupiers include Investec, Skyscanner and Morton Fraser and retail units have been taken by the likes of Sainsbury's ,Starbucks and Peter's Yard.
The top penthouses were sold for up to £1.5m each, but almost half the 900 apartments are still empty, anchor developments are still awaited, and completion date was put back to 2016 by Gladedale, which ditched plans for a five-star hotel. The developer did however sell the two principal office buildings in 2007 and 2013, both to Aviva.
Charles Ferguson Davie, chief investment officer of Moorfield, said: "The Quartermile team have done a fantastic job so far and we will aim to continue to focus on the creation of a vibrant community at Quartermile."
Paul Curran, managing director at Quartermile, said: "We are delighted to have the backing of Moorfield to take Quartermile forward."