(Reuters) - U.S. Bank NA and Oppenheimer & Co have agreed to pay fines to settle charges from the U.S. Commodity Futures Trading Commision over use of unapproved communications channels, the regulator said on Tuesday.

U.S. Bank will pay $6 million to settle the charges that it violated CFTC record keeping requirements for swap dealers and Oppenheimer & Co will pay $1 million for violations of similar requirements for introducing brokers, the CFTC said in a statement.

The firms did not respond immediately to requests for comment.

U.S. Bank and Oppenheimer are the latest of dozens to be hit with penalties from the CFTC and the Securities and Exchange Commission for employees' widespread use of personal devices and apps such as WhatsApp for work communications. The CFTC alone has imposed $1.1 billion in civil penalties on 22 institutions for related violations, it said in a statement.

The CFTC found that from at least 2019, US Bank and Oppenheimer failed to stop employees, even senior ones, from sending messages via personal texts and other unapproved communication methods.

(Editing by Nick Zieminski)