The disastrous flotation last year of World Online, the Dutch internet company, returned to haunt Goldman Sachs and ABN Amro Rothschild on Thursday after a Dutch shareholder group formally sued the two banks and the company.

VEB, which represents small shareholders in the Netherlands, said it would sue shortly after World Online shares started to collapse last March. It has now formally pressed ahead with legal action almost a year to the day after the World Online IPO.