Italian energy company Enel is preparing to sell close to $5bn (€3.6bn) worth of bonds by the end of this week to become the latest European company since AstraZeneca to test the depth of investor appetite for corporate debt amid still-turbulent markets.

AstraZeneca, the Anglo-Swedish pharmaceutical group, returned to the primary new issue market for the second time in a week yesterday when it sold €750m of 8-year bonds.