This includes £3bn specifically set aside for first-time buyers.
The Council of Mortgage Lenders expects the mortgage market to shrink in 2012 to £133bn and, if so, the commitment by HSBC will expand its market share to 11.3%, the largest market share the bank has ever had.
Of the £15bn HSBC will be making available for 2012, the majority will be new money into the mortgage market.
HSBC said the commitment would help in the region of 150,000 homeowners and over 27,000 first-time buyers.
Martijn van der Heijden, head of lending at HSBC, said: “In 2011 we offered UK borrowers some of the most competitive rates around and we plan to continue this in 2012.
“While some estimates suggest mortgage lending in the UK will fall this year, HSBC has no intention of closing its doors to customers nor will we compromise our reputation for responsible lending.
“Today’s announcement demonstrates HSBC’s commitment to continuing to help people move up or indeed take the first step onto the housing ladder.”
