New York is suing Credit Suisse Securities and affiliates, claiming they misled investors about the care taken in evaluating their residential mortgage-backed securities.
The suit filed Tuesday in Manhattan under New York's Martin Act alleges Credit Suisse deceived investors before the 2008 market collapse.
Attorney General Eric Schneiderman (SHNEYE'-dur-muhn) says the securities sponsored and underwritten by Credit Suisse in 2006 and 2007 have lost about $11.2 billion.
Zurich-based Credit Suisse says Schneiderman "recycles baseless claims" from private lawsuits.
Schneiderman is co-chair of a task force established by President Barack Obama to investigate misconduct in the pooling and sales of those securities.
Last month, he filed a similar lawsuit against JPMorgan Chase & Co., alleging fraud by Bear Stearns before its 2008 collapse and subsequent sale to the New York bank.