Fannie Mae sued nine banks, alleging that their manipulation of the benchmark London interbank offered rate, which four of them have admitted, cost the mortgage-financing company about $800 million, Bloomberg News reported yesterday. The U.S. government-owned firm alleged that the banks, including Bank of America Corp., JPMorgan Chase & Co. and Citigroup Inc., acted to suppress the rate through quotes they submitted to the British Bankers Association, according to the complaint filed in court on Wednesday. The alleged suppression of the rate caused Washington, D.C.-based Fannie Mae to lose as much as $332 million on interest-rate swaps with Barclays Plc, UBS AG, Royal Bank of Scotland Plc, Deutsche Bank AG, Credit Suisse Group AG, Bank of America, Citigroup and JPMorgan, according to the complaint.