UBS AG, Switzerland's biggest bank, may be fined more than $1billion by U.S. and U.K. regulators for trying to rig globalinterest rates, more than double the amount levied against BarclaysPlc, according to a person familiar with the probe.

The fines from the U.S. Commodity Futures Trading Commission,the U.K. Financial Services Authority and the U.S. Department ofJustice may be announced as early as next week, said the person,who asked not to be identified because the information isn'tpublic. The final figures are still being negotiated and couldchange, three people familiar with the probes said.

Global authorities are investigating claims that more than adozen banks altered submissions used to set benchmarks such as theLondon interbank offered rate to profit from bets on interest-ratederivatives or make the lenders' finances appear healthier.Barclays, the U.K.'s second-biggest bank, agreed to pay 290 millionpounds ($467 million) in June to resolve the U.S. and U.K. Liborprobes.