All but one of the nation's seven largest banking groups posted net profits in the first half through September despite shouldering 1.1 trillion yen in credit costs for bad loans, according to earnings reports released Monday.

The exception was Mitsubishi Tokyo Financial Group, which foundered in the red.

The country's major lenders were all deep in deficit for the year ending March 31. The size of banks' outstanding bad loans fell slightly from a record 26 trillion yen in March but remained high at 24 trillion yen.