U.S. Bank has acquired the units of Union Bank’s institutional trust business that focus on retirement plans, labor management trusts, and registered investment advisors, U.S. Bank’s parent, U.S. Bancorp, announced late Wednesday. As a result of the deal, which closed yesterday, U.S. Bank’s Institutional Trust and Custody division acquired approximately 4,300 client relationships representing $42 billion in assets under administration, U.S. Bancorp said.

“This acquisition is a great fit for U.S. Bank and solidifies us as a leading provider of institutional trust and custody services by significantly increasing U.S. Bank’s scale supporting the retirement services, labor management, and registered investment advisor markets,” Terrance Dolan, vice chairman of the bank’s Wealth Management and Securities Services division, said in a statement.

Jeff Kerr, president of U.S. Bank’s Institutional Trust and Custody division, added that the deal increases the division’s presence on the West Coast and complements its existing suite of services. “We look forward to putting the resources of U.S. Bank to work for our new clients,” he said.

Union Bank’s decision to exit the retirement plans services, labor management trust services, and registered investment advisor business segments was made after thoughtful analysis of its market position, Marianne Bamonte, senior vice president and Institutional Services division manager of Union Bank, said in a statement. “The sale of these business segments will allow us to strategically reinvest capital in other areas to the long-term advantage of our clients and Union Bank. At the same time, we are confident U.S. Bank’s scale will ensure continued high quality services and support to the client relationships they are acquiring,” she said.

The terms of the transaction were not disclosed.

Minneapolis-based U.S. Bank is the fifth largest commercial bank in the United States. Its parent, U.S. Bancorp, operates 3,085 banking offices in 25 states and 5,053 ATMs.