By Emily Flitter and Jamie McGeever
NEW YORK/LONDON (Reuters) - Swiss bank UBS AG has suspended U.S.-based veteran currency trader Michael Velardi, one of up to six traders placed on leave this week, pending ongoing international investigations into allegations of collusion and market rigging, a source familiar with the matter said on Friday.
Velardi, 52, who joined Swiss Bank Corp in 1995 from Lloyds in New York, declined to comment when reached by phone.
A spokesman for UBS declined to comment.
The source said up to six UBS traders, including Velardi, had been suspended this week around the world as the Swiss bank tries to stay ahead of the wide-ranging probe.
UBS is the world's fourth-biggest currency trader, according to the latest Euromoney poll, seeing just over 10 percent of the $5.3 trillion that flows through the global market on an average day.
In its fourth-quarter results on February 4, UBS said it expected higher charges for litigation, regulatory and similar matters in 2014. UBS already has a 1.7 billion Swiss franc ($1.9 billion) reserve to deal with legal tangles.
It also said several class-action lawsuits relating to the foreign exchange probe had been filed against it and other banks.
UBS approached U.S. authorities in September with information relating to an industry-wide probe into alleged rigging of currency markets, in the hope of gaining antitrust immunity if charged with wrongdoing.
It sought to take advantage of a programme from the Justice Department's antitrust division under which the first company to report misconduct relating to a cartel can earn immunity from antitrust charges if it cooperates and provides information about other members of the group, Reuters exclusively revealed last month.
Authorities in the United States, Britain, Switzerland, Germany and Singapore are looking into allegations of collusion and manipulation of the global foreign exchange market.
They are examining not only whether traders from different banks worked together to influence currency prices, but also whether they traded ahead of their own customers or failed to accurately represent to customers how they were determining the prices.
The suspensions at UBS this week bring the total number of foreign exchange traders suspended, placed on leave or fired to around 30. Of that total, UBS accounts for up to seven.
($1 = 0.8870 Swiss Francs)
(Editing by Paritosh Bansal and Mark Potter)