The Tokyo Stock Exchange said it suffered a trading system glitch on Tuesday, preventing some brokerages from being able to place orders.

The Tokyo bourse said one of the four lines in its trading system linking it and securities firms went down around 7:30 a.m. and remained offline throughout the day. The problem was caused after it received an extraordinary amount of data from a brokerage during a routine checkup of the system.

The excessive volume of data was sent by Merrill Lynch Japan Securities, according to a source familiar with the matter.

Trading began at 9 a.m. as usual after the TSE used the remaining three lines, but major brokerages including Nomura Securities Co. and Daiwa Securities Co. were forced to stop accepting customer orders for some stocks.

The bourse said orders from nearly 40 securities houses were affected, even though it had asked them to reconnect their trading system to the remaining lines about 30 minutes after the glitch. The volume of buy and sell orders which could not be executed remains unclear.

"We're responsible (for the trouble) as a market operator," said Ryusuke Yokoyama, chief information officer of Japan Exchange Group Inc., an operator of the bourse at a press conference. "We lacked communication with securities firms."

The glitch was found in the system for accepting buy and sell orders for stocks, exchange-traded funds, real estate investment trusts and convertible bonds.

Yokoyama declined to disclose which brokerage mistakenly sent the enormous quantity of data to its trading system. But he said the securities house which caused the glitch updated its own trading system on the weekend.

The TSE said the stock market will open normally on Wednesday.

SMBC Nikko Securities Inc. said it temporarily halted handling orders from customers, while Nomura Securities said it resumed accepting customer orders in the afternoon.

An official at a major brokerage said, "We cannot deny the possibility that (the system failure) affected our customers."

Trading volume on the main section of the TSE rose to 1,568.50 million shares from Friday's 1,489.05 million shares despite the trouble.

In 2005, the TSE temporarily suspended all stock trading due to a computer failure.