The top federal prosecutor in Manhattan says he's suing Bank of America for $1 billion for mortgage fraud against Fannie Mae and Freddie Mac.

U.S. Attorney Preet Bharara says Countrywide, which was later bought by Bank of America, had procedures designed to process loans at high speed and generated thousands of fraudulent loans.

Bharara says it's the first civil fraud suit brought by the Justice Department concerning loans that were later sold to Fannie and Freddie.