The biggest Wall Street banks have spent more than $93 billion dealing with the fallout from the housing bust, settling disputes with the U.S. government and homeowners. Now they must face the Germans.

HSH Nordbank AG, DZ Bank AG and Sealink Funding Ltd. are among firms that filed more than 30 lawsuits against Wall Street lenders in New York state court last year claiming they were sold flawed mortgage products. The litigation may contribute to about $25 billion in further costs for banks to resolve claims on bonds not backed by the government, Compass Point Research and Trading LLC estimates.