UBS (UBS) is reportedly close to paying "at least hundreds of millions of dollars" in penalties to settle U.S. tax evasion violations at Credit Suisse, the Swiss banking rival it acquired in 2023.

The potential settlement with the U.S. Justice Department could come as soon as this week, the Wall Street Journal reported Thursday. It follows a 2014 plea agreement where Credit Suisse admitted to helping wealthy Americans avoid paying taxes.

As part of that earlier agreement, Credit Suisse said it would disclose American accounts but whistleblowers alleged that the Swiss bank continued to hide accounts.

Credit Suisse Closed, But Didn't Report, Some Accounts

The Justice Department has reportedly questioned the bank over accounts totaling hundreds of millions of dollars that were closed soon after the plea deal, but never reported to the U.S. government. That meant some American Credit Suisse account holders were able to move accounts to other tax havens before the government was aware of the money, per the Journal.

The 2014 plea deal included $2.6 billion in fines, and UBS set aside about $4 billion when it acquired Credit Suisse to handle ongoing investigations and lawsuits, the Journal reported.

In 2023, a Senate investigation found that the bank had likely hidden hundreds of millions of dollars in accounts following the plea deal, and didn't inform U.S. regulators of the accounts' existence until whistleblowers reported the accounts.