Three of Japan’s biggest banks on Wednesday unveiled sharp falls in first-half results and cut their full-year profit forecasts because of losses related to subprime mortgages.

The announcements from Mizuho Financial Group, Shinsei Bank and Aozora Bank provide the strongest evidence yet that Japan’s financial sector has not escaped the fall-out from the US subprime crisis, even though Japanese lenders have fewer investments in subprime-related products than their overseas rivals.