The funding line will be launched under the name Keystone Buy to Let Mortgages and products will be aimed at both individual and limited company investors who already own at least one residential investment property.
The whole application process will be carried out exclusively by Mortgages for Business.
The range includes a selection of fixed and discounted rate buy-to-let mortgages for vanilla, HMO and multi-unit property.
David Whittaker, managing director of Mortgages for Business, said: “Over the past few years it’s been increasingly difficult for professional landlords with decent sized portfolios to secure funds for medium-sized loans.
“This has not only inhibited their ability to purchase “vanilla” buy-to-let property but also means they struggle to find finance for more complex deals such as HMOs or multi-unit properties and to make acquisitions in limited company vehicles.
“Given the importance of the private rental sector as a safety net to the housing market this gap in the market needed filling.”
Rob Lankey, managing director of commercial mortgages, at Aldermore, said: “The team at Mortgages for Business has been vital in identifying this gap in the market, defining the product set and the lending criteria.
“Their experience of distributing an exclusive funding line under the Keystone banner in 2007 was crucial in launching this new product range and we know borrowers will receive excellent customer service at every stage of the process.
“All applications will be processed in a timely, streamlined manner by a helpful, friendly and efficient team.”