Libor, the nearly 50-year-old global borrowing benchmark that became a byword for corruption, is headed for the trash heap of history.

The U.K. Financial Conduct Authority will phase out the key interest-rate indicator by the end of 2021 after it became clear there wasn’t enough meaningful data to sustain the benchmark that underpins more than $350 trillion in securities, Andrew Bailey, the head of the regulator, said in a speech Thursday at Bloomberg’s London office.