Social investment groups have slammed the United Nations for failing to practise what it preaches by investing in companies that do not adhere to its corporate ethics rules in its pension fund.

The $29bn (€25bn) fund invests in at least a dozen companies that do not subscribe to its global compact, according to fund managers who reviewed 400 of its investments. The compact is a voluntary list of 10 ethical standards and is widely used as a blueprint for sustainable investing by pension funds.