Ratos, a quoted Swedish private equity firm, and Lehman Brothers' real estate arm have been forced to extend their SKr4.914bn (€544m) bid for Tornet, a Stockholm-listed property company, when acceptances for the offer failed to reach 90%.

Arne Karlsson, chief executive of Ratos, said it was unclear why the SKr190-a-share offer had fallen 8.1% short of the 90% needed for the minority shareholders to be compulsorily bought out in Sweden's largest public to private deal this year