It was not until the afternoon that technicians at the Tokyo Stock Exchange were able to get their computerized trading system working again. But in the 90-minute session, the benchmark Nikkei index of 225 selected issues soared nearly two percent to 13,867, a 53-month high.
Exchange officials say the network, which is also linked to bourses in Sapporo and Fukuoka, failed to boot up Tuesday morning, causing all six computer servers that process orders to fail.
Tokyo Stock Exchange Managing Director Tomio Amano apologized to investors for the worst systems failure to hit the bourse since it ended traditional floor trading and shifted entirely to computerized dealing in 1999.
Mr. Amano says the problem was caused by software installed last month that processes data from investment banks. He says the exchange might seek compensation for damages from Fujitsu, the developer of the software.
The exchange, which has recently seen record trading volume, last month instituted an emergency upgrade of its computer system to handle increased capacity for orders.
Trading of futures and options was not affected.
The Osaka Stock Exchange, which is on a different computer system, operated normally and reported a surge in volume while the exchanges in the three other cities were off line.
Kaoru Yosano, who was appointed economic and fiscal policy minister only on Monday, calls the system failure a serious problem. Mr. Yosano says the trouble is of concern not only to Japan, but the entire financial world.
The Financial Services Agency late Tuesday, invoking the Securities and Exchange Law, ordered the Tokyo bourse to report on the cause of the disruption and take measures by November 15th to ensure such a failure does not happen again.
The Tokyo Stock Exchange is one of the world's biggest and shares of some the largest international companies are listed on the exchange.