When entering a relationship, the last thing you usually think about is how it is going to end. But the intricacies of a partnership often make getting out of it very tricky and the help of a third party is sometimes required.

The growing use of derivatives in fund management portfolios has created this problem for institutional investors, which, in the past 18 months, have found that leaving one asset manager in favour of another is not as simple as changing the name on a contract.