Ritchie, who has successfully redefined the housing body’s role after a period of cuts and restructuring, will leave the HCA at the end of January.
HCA chairman Robert Napier said: “Pat has built a strong agency with a clear remit from Government and a track record for delivery.
“I had hoped to retain Pat in the role of HCA chief executive, however the board and I will now continue with the process to recruit a permanent chief executive as quickly as possible.”
Pat Ritchie said: “I have enjoyed leading the HCA for the last two years and I will be sorry to leave.
“However I am thrilled to be returning to the North East. It is an exciting opportunity to shape the future of the city in which I’ve spent much of my working career.
“I am very proud of the strong organisation the HCA has become. It has been a period of change and challenge at the HCA and across the sector; however the Agency now has a clear direction and a vital role in delivering the Government’s housing, land and growth ambitions.”