The state of New York is suing HSBC over allegations it ignored a law designed to protect US homeowners from losing their properties.
According to the lawsuit, the bank's "illegal business practices make it more likely that homeowners will unnecessarily lose their homes".
New York state law requires lenders to make a request for judicial intervention when they attempt to sue a homeowner in order to recoup mortgage repayments.
The state accuses HSBC of being too slow to file the relevant paperwork in 300 of its foreclosure cases.
New York state attorney general Eric Schneiderman said: "[HSBC's] business practices not only violate the law, but they make it more likely that homeowners will unnecessarily lose their homes."
HSBC has responded by saying it is committed to complying with the laws regarding foreclosure in the US.
Mr Schneiderman recently said he was prepared to sue Bank of America and Wells Fargo for violating a $25 billion mortgage settlement.
By Asim Shah