He said the “project to build and establish StreamBank was always bookended”.
The bridging and development finance lender gained its full banking licence earlier this year which allowed it to offer savings accounts. It also provides commercial mortgages.
Pateman (pictured) added: “We built the team and all the operational and control framework elements demanded of a well-run bank in my first two years with the firm. As the bank continues to mature and develop, customer numbers grow, and we come towards the end of the first year of operation as a bank, the time is right to move on to the next chapter.
“I am very grateful to the board and to Alex Pusco, the founder and shareholder, for giving me the opportunity to lead the build of StreamBank – creating a niche specialist property lender.”
He said: “We have established truly solid foundations for the future growth and success of the bank and this achievement would not have been possible without the hard work, professionalism and energy of the founding team. Working with them on this journey has been a true privilege and I am grateful for their unstinting support.”
Pateman will be replaced by chief financial officer Jean-Pierre Flais on an interim basis.
John Reed, chairman of StreamBank, said: “Steve has done a fantastic job of both building and leading his in house team and external advisers in securing the banking licence and building the business. He has established StreamBank as a real presence in the specialist property finance market and leaves with our thanks and huge appreciation for a job well done.
“The board will now work with Jean-Pierre on the bank’s plans for its second year of trading whilst focusing on the search for a permanent successor.”
Flais added: “I have worked closely with Steve and the board on this project for over three years and I am pleased to step into the CEO role as we turn our efforts to generating another year of growth underpinned by solid foundations and a great team.”