A member of the ExxonMobil pension scheme has taken Northern Trust to court, claiming the US custodian and asset manager breached its fiduciary duties over its securities lending practices, which resulted in substantial losses for the scheme over the past two years.

Joseph Diebold, who has filed the case on behalf of the pension scheme attached to one of the world's largest energy companies, is seeking to lead a class action against Northern Trust, claiming that collateral collected from lending out of shares had been invested too riskily by Northern Trust since the start of 2007 to the present day.