Controversial lending practices that proliferated ahead of the financial crisis have made a comeback this year as investors flock to corporate debt that offers either higher yields or the promise of being pegged to potentially rising central bank interest rates.

So-called covenant-lite loans that strip out safeguards for investors, dividend deals in private equity-controlled companies, and a third class of instruments, payment-in-kind toggle notes, were widely criticised as part of the easy lending that led to the credit crunch.

Although they resurfaced as financial markets recovered, the past few months have seen a surge in such deals as market conditions moved in favour of corporate borrowers.