Tokyo shares plunged Thursday as the strong yen dragged down the earnings prospects of major exporters in the manufacturing and high-tech sectors.

The benchmark Nikkei 225 index closed 240.38 points lower at 11,515.02, briefly flirting with the postbubble low of 11,477.56.

The tumble washed out gains made earlier this week when the Bank of Japan pumped more money into the banking system to try to boost the economy.