It was only last year that Carillion took over 66.7% of Ask Real Estate but with its finances in crisis it is beating a swift retreat.
Carillion has also sold its 50% interest in Ask Carillion Developments LLP.
Dukehill, the buyer, is a vehicle of the family of 87-year-old Roy Richardson, who with his twin brother Don developed the Merry Hill Shopping Centre in Dudley in the 1980s.
Ask Real Estate and Ask Carillion Developments carry out commercial property development activities, together with various partners, in the north of the UK, including Manchester, Liverpool and Leeds.
Current projects in the portfolio include the £500m First Street development in Manchester city centre and a £200m arena and conference centre at Gateshead Quays.
Carillion has been urgently looking to offload non-core assets after making a pre-tax loss of £1.15bn in the first six months of 2017.
The assets being sold contributed £4.1m of revenue last year and £11.6m profit before tax. Carillion said that the disposal was expected to generate ‘a modest profit’ on disposal to help reduce debt.
Ask Real Estate managing director John Hughes and finance director Jonathan Cross, who together own the other third, will retain their executive positions.
Carillion interim chief executive Keith Cochrane said: “We are pleased to be able to announce further progress. Much remains to be done, and we are continuing to execute our plans to refocus the business, reduce cost and strengthen our balance sheet.”