NEW YORK - Citigroup Inc.'s private banking unit said Wednesday that it had agreed to acquire Winter Capital International LLC, a portfolio management firm, to enhance its own appeal to the "ultra-wealthy."

The price was not disclosed. Clark B. Winter, the firm's founder, would join Citibank Private Banking as chief global investment strategist, reporting to Peter K. Scaturro, chief executive officer of the unit.

Mr. Winter is a former executive of Lazard Freres & Co and J.P. Morgan & Co.

Citibank said this year it was trawling for boutique investment management firms to beef up its private banking operations, particularly as it chases after the high end of the affluent market. Winter Capital puts together investment portfolios for individuals and institutions in the United States and abroad.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.