The decision takes effect immediately, however SSM plans to honour all current pipeline business and has notified brokers of their submission deadlines.
The Scarborough Group said the move had resulted in a 'small number' of job losses, with affected staff entering into a consultation period, however did not confirm an exact number.
Scarborough Group relationship manager Simon Evans said: "We have to accept that the world has changed since last autumn and our business needs to respond accordingly.
"Given the much-reduced appetite for originating mortgage lending and trading mortgage assets, we have responded to market trends currently and as we expect them to unfold over the coming months."
All existing SSM loans will continue to be administered by the Scarborough Building Society Group.
