The U.K.'s Financial Services Authority this week fined Swiss Bank UBS £160 million ($260.2 million)—the largest fine ever imposed by the FSA— to settle allegations that it attempted to rig various interbank interest rates to increase trading profits relating to the London Interbank Offered Rate and the Euro Interbank Offered Rate.

The fine is unrelated to the £29.7 million ($47.5 million) penalty issued against UBS last month for systems and controls failures that enabled a rogue trader to lose $2.3 billion in 2011.

The UBS fine also marks the second fine issued by the FSA in respect to LIBOR. The first fine of £59.5 million was issued against Barclays Bank back in June 2012.

With the latest fine, UBS's breaches of the FSA's requirements stem from a number of issues, involved a significant number of employees and occurred over a period of years in a number of countries, including Japan, Switzerland, the U.K., and the United States.

UBS traders and managers “manipulated UBS's submissions in order to benefit their own positions and to protect UBS's reputation, showing a total disregard for the millions of market participants around the world who were also affected by LIBOR and EURIBOR,” Tracey McDermott, FSA director of enforcement and financial crime, said in a prepared statement.

Among the allegations, UBS traders colluded with other banks and brokerage firms in attempts to influence Japanese Yen (JPY) LIBOR submissions. Corrupt brokerage payments were made to reward brokers for their efforts to manipulate the LIBOR submissions of panel banks. 

The FSA identified at least 2,000 documented requests for inappropriate submissions, as well as an “unquantifiable number of oral requests, which by their nature would not be documented,” the FSA said. At least 45 individuals—including traders, managers and senior managers—were involved in, or aware of, the practice of attempting to influence submissions, according to the FSA.

Yet, neither UBS's compliance nor group internal audit detected this "routine and widespread manipulation" of the submissions, which undertook five audits of the relevant business area during the relevant period, the FSA said. “Over an extended period, UBS allowed this to happen through its failure to control its business appropriately to ensure that LIBOR and EURIBOR submissions properly reflected the relevant requirements,” McDermott said.

The FSA said it continues to pursue a number of other significant cross-border investigations in relation to LIBOR and EURIBOR.