Co-head of the bank's rates business, Yvan Ducrot, and global head of short-term interest rates trading, Holger Seger, are among a group of Zurich-based traders who have been suspended pending further inquiries, a source close to the case told the Financial Times newspaper.
UBS declined to comment when contacted by AFP.
Swiss authorities announced at the beginning of February they had launched an inquiry into the possible manipulation of Libor (London Interbank Offered Rate) and Tibor (Tokyo Interbank Offered Rate), which serve as benchmarks for the wider money markets.
The Competition Commission (COMCO) said collusion between derivative traders at a number of financial institutions might have influenced the rates in their favour.
About a dozen other banks are involved in the probe, among them UBS rival Credit Suisse plus Citigroup, Deutsche Bank, JP Morgan Chase and Royal Bank of Scotland.
In December, Japan's financial watchdog ordered a temporary suspension of trading activities at Japanese subsidiaries of the US bank Citigroup and UBS, accusing them of trying to manipulate interbank rates.
Tibor and Libor rates are based on central bank reference rates and determine the level of interest paid by participating financial institutions on interbank markets in London or Tokyo.
The rates are used as benchmarks in many contracts and financial products such as home mortgages.