The Justice Department said it's suing UBS over the sale of residential mortgage-backed securities from 2006 through 2007, just before the Great Recession hit. "The fraudulent actions by UBS as alleged in the complaint contributed to the 2008 financial crisis, which resulted in lasting economic harm to the nation and unnecessary suffering for Americans," said Principal Deputy Associate Attorney General Jesse Panuccio, in a statement. UBS misled investors about the quality of billions of dollars in subprime and Alt-A mortgage loans backing 40 RMBS deals, the government says. The Justice Department has settled with several banks over crisis-era mortgage bonds. UBS had already announced it plans to contest the lawsuit.