Michael Slade will step down as chief executive of Helical Bar next year.
Mr Slade made the announcement as the group posted strong returns for H1 2015.
The CEO, who will become a non-executive chairman, will be replaced by director Gerald Keye, who has been with the company for 21 years.
In the six months to 30 September, the developer reported an 18.1 per cent increase in the value of its London investment portfolio to £417m, up from £353m in H1 2014.
The group’s total net income was up 55 per cent for the period to £107.6m, compared with £69.2m the previous year.
Development profit increased to £18.7m, compared with £15.6m in H1 2014.
Mr Slade said: “I have been chief executive of Helical since 1984 and one of its major shareholders for most of that period.
“In July 2016, at the next AGM, I will hand over the reins to Gerald Kaye, my fellow director for the past 21 years.
“I have been asked to take over from Nigel McNair Scott, our current chairman, when he retires at next year’s AGM and I am delighted to be able to continue to be part of the Helical story.”
The outgoing chief executive said the group’s portfolio was primarily targeted towards London for capital growth and development profits, and to the regions for high yielding investment assets and trading profits.
“London continues to deliver strong returns and the company is looking to increase its commitment to London by retaining its refurbishment schemes at C-Space, Charterhouse Square and, most notably, the Bower,” he said.
“Our larger balance sheet and our belief that the London office market will show continued growth has encouraged the company to increase its exposure to locations which we believe will outperform.”