The Mortgage Shop, which specialises in first-time buyers, has 16 branches and 36 advisers across Northern Ireland.
As part of the deal estate agency chain Ulster Property Sales will also be part of Stonebridge.
Siobhan McAleer, owner of The Mortgage Shop and Ulster Property Sales, said: “We are now amalgamating into the Stonebridge Group and the move will enable us to access the very best mortgage deals out there.
“The bonus in joining Stonebridge is that we can now offer the same flexibility with insurance products such as mortgage protection, critical illness and home insurance.
“The Mortgage Shop’s reputation has been built on quality which Stonebridge have clearly recognised. They are also driven by the same quality standards and this amalgamation will mean we are able to maintain our high quality in mortgage advice and offer better deals in protecting that mortgage.”
In quarter one 2015 Stonebridge upped its number of mortgage completion cases by 59% and the value of those cases by 62%.
Richard Adams, managing director of Stonebridge Group, said: “We are incredibly pleased to be able to welcome Siobhan and her two businesses, The Mortgage Shop and Ulster Property Sales, into Stonebridge Group.
“These two brands, and their range of offices, have been leading lights in the provision of mortgage and protection advice in Northern Ireland for more than 20 years and have a strong reputation for the high quality of their advice and their commitment to their client base.
“Siobhan remains the driving force and we believe that by joining Stonebridge she will be able to use our extensive resources and relationships in order to develop these businesses further and to cement her number one position within the Northern Ireland broker market.
“This is a major coup for Stonebridge and proves that we have become the natural home for progressive advisory businesses looking for specialist support.”
McAleer set up The Mortgage Shop in 1992 prior to which she spent four years as a branch manager with Abbey National (now Santander).
She added: “Stonebridge’s state of the art IT systems will not only deliver the best offers for mortgages and insurance, but will also keep our clients informed throughout the home buying process.
“The efficiency of this IT system will reduce the stress and time involved and will mean we can keep our clients up to date with each stage of the process.”
