Junior creditors to the £9bn (€13.3bn) debt package funding Kohlberg Kravis Roberts' buyout of Alliance Boots are being offered an unprecedented amount of equity to improve the terms of their lending in the latest sign of a shift to risk aversity in the debt markets.

A record £750m mezzanine component of the debt package, the most junior tranche, will include an additional £250m in "stapled equity" to make it more attractive to lenders.