The operation is to be integrated into UBS' wealth management and business banking group.
Julius Baer's North American wealth management unit, which is based in New York and has offices in Los Angeles, Palm Beach, Fla., and Montreal, has $4 billion of assets under management. The deal, terms of which were not disclosed, is expected to close in the first quarter.
The deal would be another step in UBS' expansion of its wealth management business. It would be the banking company's sixth major acquisition since 2003.