Hartford law firm Izard Nobel has filed a lawsuit seeking class action status on behalf of all U.S. purchasers of securities issued by Canadian Imperial Bank of Commerce.

The class includes those who purchased CIBC securities between May 31, 2007 and May 28, 2008. The suit, filed in U.S. District Court for the Southern District of New York, alleges that, among other charges, 35 percent of CIBC’s hedged subprime exposure “was entrusted with a substantially undercapitalized financial guarantor.”

On Dec. 6, 2007, Izard Nobel said, CIBC revealed that its write-downs had already reached $1 billion, and warned of significantly higher losses related to its $9.8 billion in hedged exposure to the subprime market. On May 29, CIBC took a $2.51 billion loss related to its structured credit activities.