Mizuho Financial Group Inc., Japan's second-biggest bank by revenue, cut its full-year profit forecast by 55 percent because of losses on investments and rising bad-loan costs.

The Tokyo-based bank, which reported net income of ¥311.2 billion ($3.2 billion) in fiscal 2007, expects profit of ¥250 billion for the year ending March 31, it said in a statement Friday. That's down from a May forecast of ¥560 billion.

Smaller rival Sumitomo Mitsui Financial Group Inc. cut its profit estimate by almost two-thirds this week, citing credit-market losses.