The Yale University endowment, which has long been seen as a successful model for fund management, lost at least 25 per cent in value in the four months to the end of October, and will be unlikely to show any return next year.

The loss, revealed in a letter sent yesterday to Yale faculty and staff, follows the news that the Harvard endowment had lost at least 22 per cent since the end of June and would lose possibly 30 per cent in the year to June 2009.