(Reuters) - New details from court documents and sources close to the Libor scandal investigation suggest that groups of traders working at three major European banks were heavily involved in rigging global benchmark interest rates. 
 
 Some of those traders, including one who used to work at Barclays Plc in New York, still have senior positions on Wall Street trading desks. 
 
 Until now, most of the attention has involved traders at Barclays, which last month reached a $453 million settlement with U.S. and UK authorities for its role in the manipulation of rates. Now, it is becoming clear that traders from at least two other banks - UK-based Royal Bank of Scotland Group Plc and Switzerland's UBS AG - played a central role. 
 
 Among them, the three banks employed more than a dozen traders who sought to influence rates in either dollar, euro or yen rates. Some of the traders who are being probed have worked for several banks under scrutiny, raising the possibility that the rate fixing became more ingrained as traders changed jobs. 
 
 The documents reviewed by Reuters in analyzing the traders' involvement included court filings by Canadian regulators who have been investigating potential antitrust issues; settlement documents with Barclays filed by the U.S. Department of Justice and the U.S. Commodity Futures Trading Commission in Washington and by the Financial Services Authority in the U.K.; and a private employment lawsuit filed by a former RBS trader in Singapore's High Court. 
 
 The scandal, which began to come to light in 2008, has become a time bomb for regulators and a big focus for politicians on both sides of the Atlantic. At issue is the manipulation between at least 2005 and 2009 of rates that are used to determine the cost of trillions of dollars of borrowings, including everything from home loans to credit card rates. 
 
 One former Barclays employee under scrutiny, Reuters has learned, is Jay V. Merchant, according to people familiar with the situation. Merchant, who oversaw the U.S. dollar swaps trading desk at Barclays in New York, worked for the bank from March 2006 to October 2009, according to employment records maintained by the U.S. Financial Industry Regulatory Authority (FINRA). 
 
 Merchant currently holds a similar position at UBS, where he works out of the Swiss bank's offices in Stamford, Connecticut, according to FINRA. He did not return requests for comment. 
 
 People familiar with the investigation said authorities are looking at whether some individuals on Merchant's trading desk tried to influence the rate on Libor by communicating with other traders in London to get a higher return on certain swaps the desk was trading. His specific role is unclear. 
 
 The Department of Justice declined to comment. 
 
 Merchant's attorney, John Kenney of Hoguet Newman Regal & Kenney, did not respond to requests seeking comment. 
 
 A UBS spokeswoman said that the bank has "no reason to believe Mr. Merchant has engaged in any improper conduct at UBS." The spokeswoman, who noted that Merchant is on a two-week vacation, declined to comment on the broader investigation. 
 
 Barclays declined to comment. In a statement, an RBS spokeswoman said the bank is cooperating with the investigation. 
 
 SPREAD FROM BARCLAYS 
 
 Earlier this week, Reuters reported that federal prosecutors in Washington have begun reaching out to lawyers for some of the individuals under scrutiny as they get closer to bringing possible criminal charges. 
 
 The dollar and euro rate-rigging appears to have begun in earnest in early 2005 in the dollar market, according to the documents reviewed by Reuters. By August of that year, Barclays traders were reaching out to traders at other big global banks to manipulate their rates to make them favorable to Barclays' trading positions. 
 
 Soon, the trading had crossed to the euro rate markets, according to the settlement documents filed in the Barclays investigation. And by 2007, traders at RBS and UBS were seeking to influence the yen rate market, according to documents filed in 2011 in Singapore's High Court and in Canada's Ontario Superior Court. 
 
 Traders at Barclays are believed to have participated in manipulating the rate for the dollar and the rate for the euro known as Euribor, according to documents filed in the Barclays settlement last month. 
 
 RBS and UBS traders are a focus of the global investigation because of their alleged involvement in seeking to influence yen-denominated rates. 
 
 Two RBS traders in London, Brent Davies and Will Hall, are alleged to have agreed to help a trader at UBS, Thomas Hayes, to manipulate yen Libor, according to court documents filed by the Canadian Competition Bureau. 
 
 UBS is cooperating with Canadian and U.S. authorities, according to people familiar with the situation. 
 
 Hayes worked at UBS from 2006 to 2009. He later moved to Citigroup where he remained until 2010, after which he left the bank. Hayes, Davies and Hall could not be reached for comment. 
 
 The documents reveal that Hayes also contacted traders at other banks in London to get them to manipulate yen rates. They include Peter O'Leary at HSBC Holdings Plc, Guillaume Adolph at Deutsche, and Paul Glands at JPMorgan. A second UBS employee sought to get a Citigroup trader, who formerly had worked at UBS, to influence rates. 
 
 None of these traders could be reached for comment. 
 
 CONDONED 
 
 In addition, a former trader at RBS, Tan Chi Min, said in a wrongful termination lawsuit filed in the Singapore High Court in 2011 that he was forced out for "improperly seeking to influence" the setting of Libor. Tan, who ran a trading desk at RBS, said in the suit that improper rate-rigging was known by some at the bank and condoned. 
 
 Tan denied trying to manipulate Libor, and alleged in the 2011 court filing, and one in March this year, that about a half dozen other RBS traders openly tried to request specific rates. 
 
 Tan's attorney, N. Sreenivasan, declined to comment because the court case is ongoing. 
 
 Beyond traders at the three European banks, authorities are still probing the role of others. 
 
 For example, traders at JPMorgan Chase & Co also interacted with some of the traders under scrutiny who worked for Barclays and RBS, according to a person familiar with the situation and court documents filed in Singapore. 
 
 Similarly, Deutsche Bank AG also had several employees whose trading is under scrutiny by authorities, according to people familiar with the situation and court documents filed in Canada. 
 
 JPMorgan and Deutsche Bank declined to comment. 
 
 (Reporting by Carrick Mollenkamp and Emily Flitter in New York; Additional reporting by Matthew Goldstein and Jennifer Ablan in New York, Rachel Armstrong in Singapore, Anjuli Davies in London and Katharina Bart in Zurich; Editing by Martin Howell and Nick Macfie) 
 
 (This story has been refiled to edit the fourth paragraph) ||||| JPMorgan Chase & Co. (JPM) and Barclays Plc (BARC) are among seven banks subpoenaed in New York and Connecticut’s investigation into alleged manipulation of Libor, according to a person familiar with the matter and company filings. 
 
 Subpoenas were sent in recent weeks to five of the banks, Deutsche Bank AG (DBK), Royal Bank of Scotland Group Plc and HSBC Holdings Plc (HSBA) in addition to JPMorgan and Barclays, the person said yesterday. Citigroup Inc. (C) and UBS AG (UBSN) received subpoenas earlier this year as part of the investigation. 
 
 New York Attorney General Eric Schneiderman and Connecticut Attorney General George Jepsen are jointly investigating alleged manipulation of the London interbank offered rate by lenders. RBS, UBS, Lloyds Banking Group Plc (LLOY) and Deutsche Bank are among the lenders regulators in Europe, Asia and the U.S. are investigating. The U.S. is conducting a criminal investigation. 
 
 Confidence in Libor, a benchmark for financial products valued at $360 trillion worldwide, has been dented by Barclays’s admission that it submitted false London and euro interbank offered rates. Robert Diamond resigned as Barclays’ chief executive after the bank was fined 290 million pounds ($454 million). 
 
 Photographer: Scott Eells/Bloomberg Pedestrians pass in front of the JP Morgan Chase & Co. headquarters in New York. Close Pedestrians pass in front of the JP Morgan Chase & Co. headquarters in New York. Close Open Photographer: Scott Eells/Bloomberg Pedestrians pass in front of the JP Morgan Chase & Co. headquarters in New York. 
 
 False Submissions 
 
 Derivatives traders requested the false submissions in the Libor and Euribor setting process, as they were “motivated by profit and sought to benefit Barclays’ trading positions,” the U.K. Financial Services Authority said. 
 
 The investigation by Schneiderman and Jepsen could broaden to include additional banks, said the person. 
 
 Jennifer Givner, a spokeswoman for Schneiderman, and Jaclyn Falkowski, a spokeswoman for Jepsen, declined to comment on the subpoenas. 
 
 Sarah Binnie, a spokeswoman for Edinburgh-based RBS, said the bank continues to receive requests from various regulators investigating the setting of Libor and other interest rates. The lender is cooperating with the investigations and “keeping relevant regulators informed,” she said in e-mail. 
 
 “It is not possible to estimate with any certainty what effect these investigations and any related developments may have on the group,” Binnie said. 
 
 Information Requests 
 
 Kathryn Hanes, a spokeswoman for Deutsche Bank, said the lender has received subpoenas and requests for information from some regulators and governmental entities in the U.S. in connection with setting interbank rates and is cooperating. 
 
 New York-based Citigroup said in a regulatory filing that subsidiaries “have received additional requests for information and documents from various U.S. and non-U.S. governmental agencies, including the offices of the New York and Connecticut attorneys general.” 
 
 Photographer: Daniel Acker/Bloomberg Traffic passes the offices of Barclays Capital in New York. Close Traffic passes the offices of Barclays Capital in New York. Close Open Photographer: Daniel Acker/Bloomberg Traffic passes the offices of Barclays Capital in New York. 
 
 UBS said in a regulatory filing that numerous agencies, including “various state attorneys general” are investigating whether there were improper attempts to manipulate Libor and other rates. A second person familiar with the matter said the bank received a subpoena from New York in February. Both declined to comment because the matter is private. 
 
 New York-based JPMorgan dropped almost 1 percent on the news. JPMorgan closed at $37.07 in New York Stock Exchange composite trading. London-based Barclays’s American depositary receipts fell 6 cents to $11.47. One receipt equals four shares. Zurich-based UBS fell 3 cents to $10.71 in New York. Frankfurt- based Deutsche Bank rose 9 cents to $30.78. 
 
 ‘Actively Reviewing’ 
 
 Joe Evangelisti, a JPMorgan spokesman, Juanita Gutierrez, a spokeswoman at HSBC, and Barclays spokesman Michael O’Looney declined to comment on the subpoenas. HSBC said in a 2012 interim report that it is “the subject of regulatory demands” and is cooperating with the investigations. 
 
 Photographer: Peter Foley/Bloomberg Workmen raise the JP Morgan Chase Inc. flag outside company headquarters in New York. Close Workmen raise the JP Morgan Chase Inc. flag outside company headquarters in New York. Close Open Photographer: Peter Foley/Bloomberg Workmen raise the JP Morgan Chase Inc. flag outside company headquarters in New York. 
 
 In addition to Schneiderman and Jepsen, Florida Attorney General Pam Bondi is “actively reviewing the Libor matter” and has issued subpoenas, spokeswoman Jenn Meale said yesterday in e-mails. Massachusetts Attorney General Martha Coakley’s office said in July it was also conducting a Libor investigation and was working with other state agencies. 
 
 Libor is derived from a survey of banks conducted each day on behalf of the British Bankers’ Association in London. Lenders are asked how much it would cost them to borrow from one another for 15 different periods, from overnight to one year, in currencies including dollars, euros, yen and Swiss francs. After a set number of quotes are excluded, those remaining are averaged and published for each currency by the BBA before noon. 
 
 To contact the reporter on this story: David McLaughlin in New York at dmclaughlin9@bloomberg.net 
 
 To contact the editor responsible for this story: Andrew Dunn at adunn8@bloomberg.net
– Recently released court documents suggest that traders at Barclays, the Royal Bank of Scotland, and UBS were most central to the Libor-rigging scandal, reports Reuters. Those three banks—much of the blame has fallen on just Barclay's up to now—employed more than a dozen traders who tried influencing dollar, euro, and yen rates. As several of those traders under investigation worked at a variety of banks over the years and still have senior jobs on Wall Street, investigators believe they made rate-fixing more systematic over the years. According to prosecutors' documents, euro and dollar rate-rigging appears to have begun in 2005, spreading into the yen rate market by 2007 by RBS and USB. Traders at JPMorgan Chase and Deutsche Bank are also reportedly under investigation. On the other hand, one former Morgan Stanley trader writes in the Financial Times that he warned of Libor-rigging going on way back in 1991. "Libor misreporting has been going on for decades," writes Douglas Keenan. "Why have investigations only recently begun?"