The world’s largest bond manager has urged regulators to structure an adequate transition period for markets to move away from the London Interbank Offered Rate, or risk investors being hit by the change.

Libor reflects the rates that banks pay to borrow from each other and was the subject of several manipulation scandals that saw banks fined and traders jailed during the financial crisis. In July, the Financial Conduct Authority announced that it would phase out the scandal-hit benchmark by 2021.