Buyer Exemplar Properties now in talks with lenders to fund completion of the development
Exemplar is believed to be in talks with lenders to form a joint venture in order to complete the development.
Glendale put the Quartermile development up for sale last September, though refused to disclose an asking price.
However, Gladedale has claimed previously it believed the completed development would be worth anything up to £500 million.
A recent estimate by CBRE, published in Quartermile's investment vehicle Gladedale Ventures annual report, valued the work in progress at the site at £47.7 million.
The 107-room aparthotel, leased to Marriot under its Residence Inn brand last year, was valued at £12.6million.
Quartermile is situated on the former Edinburgh Royal Infirmary site, which Lothian University Hospital's NHS Trust sold in 2001 to a joint venture between Bank of Scotland,Taylor Woodrow and Kilmartin Property Group.
The overall development, which includes 900 flats and more than 450,000 sq ft of office, retail and leisure space, was badly hit by the recession and remains less than half complete.
Gladedale has loans of £475 million outstanding to Lloyds Banking Group, and agreed a debt for equity swap in 2009 with the bank to wipe £500 million off its total £1billion debt.