In a postwar first, the Bank of Japan lacks a chief following the Upper House rejection Wednesday of the government's latest candidate to replace BOJ Gov. Toshihiko Fukui, whose five-year term ended the same day.

The leadership vacuum at the central bank is likely to deal a heavy blow to Prime Minister Yasuo Fukuda amid the ongoing global financial market crisis.

Fukuda told reporters that he is "keenly aware" of his responsibility for the vacancy.