For the first time, the Tokyo Stock Exchange suspended all trading early to prevent a system crash after a surge in transactions. Heavy trading followed news that the top Internet company, Livedoor, is under investigation for fraud. The benchmark Nikkei index closed down about 465 points - nearly three percent for the day.
The Tokyo bourse pulled the plug on all trading 20 minutes before the scheduled end of Wednesday's session.
The Tokyo exchange says it was swamped by massive sell orders for a second day on news that the popular Internet company, Livedoor, was raided by prosecutors in a fraud probe.
Exchange officials say they may shorten trading hours in the days ahead if the unusual deluge of orders continues.
Tokyo Stock Exchange President Taizo Nishimuro also says the bourse may have to delist Livedoor. Nishimuro says the stock was suspended from trading Wednesday morning because of the criminal investigation of Livedoor.