John Hughes has taken charge of Ask Developments after the resignation of founder and chief executive Ken Knott with immediate effect.
The Manchester-based developer issued a statement on Monday evening which said Knott's "exit from the business is totally amicable and he will remain as a shareholder."
Knott is a senior figure in the city's business community, sitting on the board of the Greater Manchester Local Enterprise Partnership which steers public investment in major projects.
Last month, Knott instructed lawyers to consider legal action against Manchester Airports Group over the procurement process to appoint a developer for the proposed Airport City.
Ask's statement said "that following achieving the critical milestone of taking the £90m First Street North phase of the project unconditional, Ken Knott has decided to leave the company and pass the reins into the capable hands of John Hughes."
Hughes has been a development director at Ask for 10 years and was made a board director in 2008. Knott set up Ask in 2000 with Simon Bate and Andy Dodd.
The initial phases of First Street are being delivered in partnership with Manchester City Council and include the new base for the Cornerhouse cinema and Library Theatre, to be called HOME.
As well as leading on First Street, Hughes has also been responsible for securing Ask's Greengate Embankment joint venture with Network Rail and Salford City Council, where construction is scheduled to commence in early 2014.
Hughes said: "Ken leaves with our best wishes, and I am sure we will work together in the future. It is an exciting opportunity for me to drive the company forward through its next phase of development. We have a highly capable team and I am looking forward to leading Ask in this rapidly changing market-place. Our projects are very well positioned to take advantage of the positive occupier and investor sentiment toward the Manchester city region."
The company's portfolio includes the Manchester business park Central Park, Leopold Square in Sheffield, Eden Square shopping centre in Urmston and Knowsley Place in Bury.