It was owned by MUFG Americas Holdings Corporation and was acquired by U.S. Bancorp in December 2022.

In 1999, UnionBanCal Corporation became a public company listed on the New York Stock Exchange.

[4][5] On November 4, 2008, the Bank of Tokyo-Mitsubishi UFJ (BTMU), a wholly owned subsidiary of Mitsubishi UFJ Financial Group (MUFG), announced that BTMU had successfully acquired all of the outstanding shares of UnionBanCal Corporation.

[10][11][12][13][14][15] On October 19, 2004, the Federal Reserve Board announced that Union Bank had entered into a written agreement to avoid criminal prosecution for money laundering.

[23] Three years later, Union Bank was again accused of money-laundering and in September 2007, the bank agreed to pay $31.6 million in penalties and forfeitures to settle government claims that it had been implicated in an elaborate drug money laundering scheme involving Mexican exchange houses known as casas de cambio.