The US Justice Department is planning to reverse its agreement not to prosecute UBS Group AG for rigging benchmark interest rates, Bloomberg reported, citing a person familiar with the matter.

A Justice Department officials said in March that banks that have non-prosecution agreements over failures to police transactions for criminal activity could see those deals withdrawn.

Swiss bank UBS, along with four other main banking units, was expected to plead guilty to US criminal charges over the manipulation of foreign exchanges rates, people familiar with the issue told on Monday.

JPMorgan Chase & Co Citigroup, British banks Royal Bank of Scotland and Barclays, and UBS had been expected to resolve forex-rigging investigations by the U. S. Justice Department later this month.

The four of the banks will likely enter pleas related to antitrust violations, people familiar with the talks have said.

Andreas Venditti, an analyst at Vontobel Holding AG in Zurich, said, "This is basically a tradeoff. They get leniency on foreign exchange and a lower fine and instead the Justice Department comes back with Libor".

He further said that UBS's cooperation in the might help the bank to protect itself from antitrust charges in that matter.

However, the bank is still exposed to fraud charges in that case, and any admission of wrongdoing could also put it in violation of an earlier deal the Zurich-based bank struck with the Justice Department

Shares of UBS dropped as much as 2.1 percent after the news. The stock was trading 0.9 % lower as of 11:00 a. m. in Zurich trading, paring gains this year to 14 percent.

In December 2012 in a non-prosecution agreement with the US to resolve a worldwide investigation into the manipulation of the London interbank offered rate, UBS promised not to commit any crimes for two years.

The agreement that was set to expire was extended through December as the Justice Department investigated currency rigging.