The biggest clear-out was made by Mizuho Holdings, the world's largest bank by assets, which wrote off 861bn yen of debt. The bank, formed by the merger of Dai-Ichi Kangyo Bank, Industrial Bank of Japan and Fuji Bank, has a further 5.75 trillion yen of non-performing loans, and plans to book a further two trillion yen of losses in the full year, double last year's total.