Japanese banks' losses from subprime mortgages have been small compared with those of financial institutions in other countries, Bank of Japan Gov. Masaaki Shirakawa said Tuesday.

"Because investment in these types of products was small to begin with, the losses have been very small compared with financial institutions overseas," Shirakawa told lawmakers at the Upper House.

Japanese banks have accounted for a small fraction of the $245 billion in global writedowns and credit losses announced since the beginning of 2007.

Mizuho Financial Group Inc., Japan's second-largest bank by revenue, said last week it lost ¥565 billion on mortgage securities, the most reported by an Asian company.