Three of the largest US investment banks, that have so far refused to support the launch of the first indexes to track the performance of derivatives based on tradeable high-yield loans, are taking steps toward a compromise with rival banks.

Citigroup, JP Morgan and Goldman Sachs have been holding back from participating in the new index, known as LevX which was launched in Europe a fortnight ago, because of a dispute over differences between US and European loan default documents.