LONDON — The benchmark is one of the most important in the world. It underpins trillions of dollars in financial products. It was the center of a huge scandal when banks were accused of rigging it.

Now Libor is going away.

British regulators said on Thursday that they wanted to phase out the scandal-plagued interest rate by 2021, replacing it with new measures that are more closely tied to the lending markets.

The London interbank offered rate, or Libor, dates back to the 1980s, when banks in Britain decided to use a uniform benchmark across their increasing range of financial products, rather than referring to various currencies and interest rates. Today, Libor is the underlying rate for a vast array of financial products, from home loans and credit cards to small business loans.

To set Libor, banks submit the rates at which they would be prepared to lend money to one another, on an unsecured basis, in various currencies and at varying maturities. But that process has been undermined in recent years.