The fate of Libor, the rate that underpins $350 trillionworth of financial contracts, has been hanging in the wind foryears. Now its future is clear: The U.K.'s Financial ConductAuthority (FCA) says Liborwill cease to exist by the end of 2021. And that means a lot ofwork for corporate treasurers, who are responsible for all thoseloan agreements, derivatives contracts, and other documents thatrefer to Libor.

The reputation of Libor, the rate at which major banks lend toone another, was tarnished by a 2012 scandal that revealed banks had manipulated the rate. But regulators' move to pullthe plug has more to do with the fact that in the wake of thefinancial crisis, interbank lending tailed off, making the bankquotes on which Libor is based largely hypothetical. In fact, inhisspeech announcing that Libor would cease, FCA chief executiveAndrew Bailey said that for one of Libor's 35 currency and maturityiterations, the dozen banks that submit quotes had, in all of 2016,done just 15 transactions big enough to be relevant.

The FCA sounded Libor's death knell as regulators were stillscrambling to settle on replacement rates. In June, the AlternativeReference Rate Committee (ARRC), a group convened by the FederalReserve, recommended that the U.S. shift to using the Treasury reporate—what people pay to borrow money overnight using U.S.Treasuries as collateral. The Fed has put out a request for comments on the recommendation and says it willbegin publishing the new rate sometime next year.