The deal comes after a £150m line was announced in January.
MFS said the latest credit line will help it fund larger cases and development exit loans for significant property projects.
“The funding line has been sourced from a leading global hedge fund that has over £10bn in assets under management,” the lender said.
“This latest funding arrangement is part of MFS’ long-term goal of increasing its loan book and expanding its institutional funding partnerships.”
It added: “With enquiries rising, additional funding has been sourced so that loans can be deployed quickly.”
Since its inception, MFS noted it had delivered more than £1.05bn worth of specialist finance loans covering a variety of asset classes, from residential to commercial property.
Paresh Raja, CEO of MFS, said: “This latest funding news is a reflection of the trust and confidence MFS has effectively established over the years with its funding partners.
“By committing to the highest professional standards, I expect our loan book to continue to grow in the coming months.
“Importantly, MFS has delivered over 100 per cent volume growth in the last year despite the challenges posed by the pandemic.”