Mizuho Financial Group Inc., the nation's biggest bank by assets, said Monday its first-half net profit fell 8.4 percent from a year earlier but its bad loans shrank due to improved earnings at borrower firms.

Sumitomo Mitsui Financial Group Inc., the nation's third-largest, meanwhile reported a 62.8 percent plunge in net profit as it aggressively slashed bad loans.

Mizuho's net profit in the April-September period came to 233.9 billion yen. The bank blamed sluggish demand for loans as well as appraisal losses on bond holdings amid rising long-term interest rates.