Daiwa Securities SMBC Co. said Friday that a mistaken order placed by one of its traders minutes before the start of morning trading has caused it to suffer a 500 million yen loss.

The incident came as the Japanese securities industry is trying to recover from a series of blunders that have embarrassed the Tokyo Stock Exchange and two domestic brokerages -- Nikko Citigroup Ltd. and Mizuho Securities Co.

The latest clunker is likely to raise fresh calls for corrective measures.

According to Daiwa SMBC officials, a trading assistant received a sell order from a financial institution by phone, but wrote the wrong name of the stock on a memo that was passed to the trader.

The trader then placed an order to sell 25,000 shares of Sumitomo Mitsui Financial Group Inc. stock before the market opened.

The name of the stock the client intended to sell was not given.

Daiwa SMBC realized the mistake at 9:05 a.m. and was able to partially cancel the order. It then bought back the rest of the shares at a loss of about 500 million yen.

Daiwa SMBC is a joint venture between Sumitomo Mitsui and Daiwa Securities Group Inc.

Kenji Kawamura, general manager of corporate communication for the group, said mistakes happen once in a while, but the size of Friday's was a rarity.

Kawamura said the brokerage has been taking measures to prevent mistakes, but, "It is impossible to completely prevent them, because it is done by humans."

The securities house did not say it would ask investors who profited from the blunder to turn over their profits.