State Street, the Boston-based bank, provides the worst service to its global custody clients, according to the annual R&M Consulting survey, published this week in Financial News.

The US bank, whose $9.5 trillion (€7.1 trillion) of assets make it the world's second-largest custodian, saw a significant drop in the score clients awarded it for service quality. RBC Global Services, the investor services arm of Royal Bank of Canada, was ranked as the overall best service provider.