UK bank HSBC has incurred a $140m (€116m) goodwill write-off relating to its recent purchase of Household International, the US consumer credit company, taking analysts by surprise.

The write-off was revealed in quarterly filings made by Household last week. It is small in relation to Household's $14bn purchase price, agreed in November 2002. However, one analyst said: "It is amazing that a purchaser of HSBC's sophistication did not carry out more thorough due diligence."