When contacted by Reuters, Fidelity spokesman Vincent Loporchio said in an email, "We have no indication that any Fidelity customer sites, accounts, information, services or systems were affected by this matter."

The company gave no further details.

JPMorgan, the biggest U.S. bank by assets, said last week that the names, addresses, telephone numbers and emails of 76 million households had been compromised by a cyber attack, making it one of the largest such thefts on record.

The newspaper, which attributed its information to two people familiar with the matter, said the attacks are now believed to involve more than a dozen targets and originated in Russia. http://bitly.com/19XGL0n

Not all the 13 institutions’ security infrastructure was breached, FT said. The U.S. Secret Service and Federal Bureau of Investigation are leading an investigation.

JPMorgan is the only company to have confirmed that information was stolen.

(Reporting By Sudarshan Varadhan; Editing by Cynthia Osterman)