A trading error in Tokyo may have cost the Japanese arm of the Swiss merchant bank, UBS Warburg, millions of francs.
UBS issued a number of statements in Japan on Friday saying an "enormous error" had been made during the day's trading.
"UBS Warburg in Japan has made a mistake during trading which could cost the company millions," a stock market employee told reporters.
Dentsu advertising agency
The mistake was made when UBS workers sold shares in the Dentsu advertising agency.
The stock was valued at 610,000 Yen (SFr 8100) per share but for reasons yet unknown the stock was traded at 16 Yen (21 Rappen or centimes) per share.
One possible theory is that the number of shares a client wished to buy was confused with the actual share price.
It is estimated that around 65,000 shares were sold at the wrong price.
UBS Warburg traders tried to immediately buy back stock at the low level as soon as they realised a mistake had been made. The extent of the financial damage is still unknown but a spokesman for the company said the bank was trying to minimise their exposure.
The Swiss bank has launched a full investigation into what went wrong.
swissinfo with agencies