“Tranche warfare” has broken out in the $450bn market at the heart of the credit crunch as hard-hit investors scrap over the pools of debts that make up ­so-called collateralised debt obligations.

Some investors in the differently rated and ranked slices of CDOs – known as tranches – have taken advantage of the ­little-noticed terms in the ­structuring of such instruments to seize control of the assets and cut off payments to other debt-holders.