Barclays has been fined $3.75m by a US regulator over its alleged decade-long failure to keep a proper record of emails, electronic records and instant messages in line with federal securities laws.

According to the Financial Industry Regulatory Authority (FINRA), federal securities laws and FINRA rules state that business related electronic records must be kept in a non-erasable and non-rewritable format known as Write-Once, Read-Many, or WORM.

The regulator said that from at least 2002 to 2012, Barclays failed to maintain appropriate electronic records including data, trade confirmations, account records and other information in the WORM format.

"Ensuring the integrity, accuracy and accessibility of electronic books and records is essential to a firm's ability to meet its compliance obligations. The format errors in this case made it nearly impossible for Barclays to verify that these key materials remained in an unaltered condition," said Brad Bennett, executive vice president and chief of enforcement.

FINRA said that Barclays failed to retain attachments to some Bloomberg emails from May 2007 to May 2010 and failed to properly retain about 3.3 million Bloomberg instant messages from October 2008 to May 2010.

Furthermore, FINRA said that Barclays's flaws in maintaining its records properly adversely impacted the firm's ability to respond to requests for electronic communications in civil and regulatory matters.

Barclays did not admit or deny wrongdoing but agreed to the entry of FINRA's findings, according to a statement from the regulator.

A spokesman for the British bank declined to comment to IBTimes UK.

FINRA is an independent regulator that oversees more than 4,100 securities firms.