Virtus Investment Partners acquired options manager Rampart Investment Management.
Terms were not disclosed. The deal is expected to close next quarter, according to Virtus spokesman Joe Fazzino.
Virtus owns boutique money management firms, including Duff & Phelps Investment Management, Euclid Advisors and Zweig Advisers.
Rampart, which has $1.4 billion under management, will continue to be led by co-founders Ronald M. Egalka, president and chief investment officer, and David R. Fraley, executive vice president, director of client services.