Dudley has announced its successor to Sandiford in Jonathan Moore, who will take over in February after spending 10 years at Manchester Building Society.
John Heron, managing director of Paragon Mortgages, said: "We are delighted to welcome Steve to Paragon, he is joining us at an exciting time.
“Our lending increased by more than 80% in the last financial year and we are expecting growth to continue through 2015.
“Steve will further strengthen our senior team and help us develop our proposition in a competitive yet opportunity rich environment."
On Moore’s appointment, Jeremy Wood, Dudley chief executive, said: "Filling the role after the great contribution made by Steve Sandiford was always going to be a hard act to follow, but Jonathan Moore has the experience and the pedigree to provide the kind of smooth transition the Society and its partners need.
“I have been very impressed with Jonathan's knowledge as well as his grasp of the kind of lending we undertake.
“Working as we do, solely through the intermediary sector sets particular challenges and I am sure that Jonathan will build on the sound foundations that Steve has put in place to take the Society to the next level."