The Northview Group’s chief executive Amany Attia will step down once a suitable replacement is found.
She has been group chief executive since 2015 and before that chief executive of Acenden, the group’s servicing arm.
Attia oversaw the rebrand to The Northview Group, with New Street Mortgages standing alongside Kensington.
She said: “I am extremely proud of what we have built… over the last few years, building on the success of these storied brands with the support of a great team.
“I will miss everyone dearly, but I am confident that the Northview Group will continue to go from strength to strength.
“I look forward to continuing to support the Northview Group during this period of transition.”
The group’s board is currently searching for a successor.
Tim Breedon, chairman of The Northview Group, said: “We are extremely grateful to Amany for her hard work in growing the business.
“We fully support her decision and she departs with our best wishes.
“We are confident that the unique position Northview Group has established in the industry, with the deep heritage of our brands, will enable us to appoint a high-calibre leader to take the company forward into its next chapter.”