New York State's Department of Financial Services said it has reached an agreement with Goldman Sachs, Deutsche Bank, Credit Suisse and Bank of New York Mellon on record-keeping for the Symphony messaging system.

The banks, part of a consortium of 14 financial institutions that have set up the Symphony service, have agreed to retain a copy of their chat messages for seven years.

They will also store duplicate copies of the decryption keys for their messages with independent custodians.

The DFS said the four represent all of the banks that it regulates within the consortium.

The New York regulator has been looking at data deletion and end-to-end encryption, among other things, as chat room transcripts and other communications at banks could help uncover evidence of attempts to rig interest and foreign exchange rates.

Under New York law, banks are obligated to retain records of their operations.

Many on Wall Street view Symphony Communications LLC as a rival to message systems provided by Bloomberg LP [and Thomson Reuters Corp, whose clients include bankers, traders and investors.

Symphony's technology, which was originally developed by Goldman Sachs, will become available to all potential customers from Tuesday.

The regulator had earlier expressed concerns over some of Symphony's features, such as its promise of "guaranteed data deletion" that could hinder regulatory investigations.

It said it believed the requirements included in the agreements announced on Monday should apply to all regulated financial institutions using Symphony in the future.