UBS, the Swiss banking group, and several Wall Street and Japanese securities companies are considering repaying the huge profits they made from last week’s “fat finger” trading error.

The repayment of the profits has become increasingly likely after the banks were criticised for profiting from the error.

Lehman Brothers, Morgan Stanley, Credit Suisse First Boston and Nomura Securities are among those thought likely to return some of the gains made after their traders spotted the error and made a fast profit.

Market sources said as much as 17 billion yen (£82 million) of profits may be returned, but would probably not be paid to Mizuho Securities, the brokerage at which the botched trade originated. Mizuho has been told it must pay about 40 billion yen to rectify the mess it caused.

The money that is returned could be put into a fund that will finance research into correcting the problems of the Japanese trading system.

The decision to repay the profits comes after Kaoru Yosano, Japan’s Finance Minister, criticised the “ugly” actions of the banks. He also slapped a humiliating business improvement order on the Tokyo Stock Exchange for its failure to prevent the error from occurring.

The TSE apologised again yesterday for not acting more quickly when alerted to the trade, in which 610,000 J-Com shares were sold for 1 yen each instead of a single share being sold for Y610,000.

Though the TSE has been criticised for not cancelling the trade sooner or suspending the shares of J-Com, the past two days have seen a shift in where the blame lies.

Foreign banking houses are now seen as the villains because they quickly bought the J-Com shares at a big profit.

Mr Yosano said: “Although I realise that their transactions were legal, it is not a beautiful story for securities firms to snap up stocks while being aware of the erroneous sell order.” The Japanese media have supported the minister’s attack, with UBS, which bought the largest number of shares, and others described as kajiba dorobo — the most despised type of thief who steals from burning houses.

UBS said yesterday that it had “no intention of retaining profits” made on the day of the error.

• The business confidence of Japan’s manufacturers rose in the quarter to December, but not as strongly as hoped. The Tankan survey showed that small companies and those outside the manufacturing sector were more confident than at any time since the early 1990s. It also found that large companies plan to raise capital expenditure by 10.4 per cent in the current financial year, compared with 12 months earlier, representing the first double-digit growth for 15 years.

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