The Office of the Comptroller of the Currency (OCC) said on Monday it sent a cease-and-desist order to MUFG Union Bank NA, the US unit of Japan's Mitsubishi UFJ Financial Group Inc, over the bank's unsafe technological practices.
The OCC found the bank engaged in "unsafe or unsound practices" related to technology and operational risk management. According to the order, the bank was also in noncompliance with certain security standards.
MUFG has begun "corrective action" and has "committed resources to remediate the deficiencies", the order said.
The bank did not immediately respond to a Reuters request for comment.
Mitsubishi UFJ is one of the world's biggest banks by assets. Last week, Bloomberg News reported the bank was weighing selling its US banking arm.