Tullett refused to comment on claims that "broker F" at "broker firm C" – mentioned in a penalty notice issued by the Financial Services Authority against UBS – was a reference to an individual at the money-broking group. The claims were made in an article in the Financial Times, which did not name its sources. The same report also alleged that Tullet was "broker firm 3" referred to in an FSA settlement this month with Royal Bank of Scotland over Libor fixing.
The broker firm, which publishes its full-year results next month, saw its shares fall as low as 266.4p at one point as the stock slipped by more than 10%. They finished the day down 17.8p, or 5.9%, at 282.8p.
Tullett was not immediately able to confirm the FT report. There is no suggestion it is one of the banks or broker firms under investigation by either the FSA or Serious Fraud Office for involvement in Libor fixing. A spokesperson said: "Tullett Prebon has never been informed by the FSA or any other regulatory authority that Tullett Prebon or any of its brokers are under investigation in relation to Libor."
Tullett's chief executive Terry Smith has been one of the most outspoken advocates of criminal prosecutions for anyone found to have attempted to fix Libor rates. In June last year, he said on his blog: "For the record, my view [is] that the banks do not have any integrity left and that criminal proceedings should be instituted against those who had manipulated Libor."
In the same blog he also sought to remind readers of the difference between banks, where traders work, and firms such as Tullett, which provide broker services. "By the way, for the information of some of the Tweeters who railed against me as a banker, I'm not. For a certain section of the populace anyone in a suit can be stigmatised as a banker. Apart from displaying sheer ignorance, I suppose this saves them thinking about the actual arguments being put forward."
Conservative MP Michael Fallon, who is a member of the Treasury select committee which has scrutinised the Libor scandal, is a non-executive director of Tullett, sitting on the board's audit committee.
More recently the role of some broker firms in the Libor scandal has come under more scrutiny. In December two men who had been at broker firm RP Martin were among those who had their homes raided as part of an SFO investigation. They were later released, without charge, after questioning.
Last month Icap, another interdealer broker, was brought into the FSA probe into alleged manipulation. It has suspended one employee and put three others on administrative leave while investigations continue.
Responding to the FT claims, Gary Greenwood, an analyst at Shore Capital, said: "To date, Tullett has denied any wrongdoing and, unlike its larger rival Icap, has not yet suspended or placed any employees on administrative leave.
"While it appears increasingly likely that the interdealer brokers may have been complicit in Libor rigging, the fact that they are not directly involved in the rate setting process means that we believe any potential fines/penalties will be considerably lower than those levied on the guilty banks ... For those, like us, who believe that the interdealer brokers are unlikely to suffer anywhere near as big a financial penalty as the banks, this could create buying opportunities."
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