CONSHOHOCKEN, PA, February 1, 2021 – Rosemont, a private investor in employee-owned asset and wealth management firms, announces the sale of Rosemont Partners III, LP’s minority equity interest in Boston Common Asset Management, LLC. Rosemont’s interest was acquired by Affiliated Managers Group, Inc. (NYSE: AMG) and employees of Boston Common.

Boston Common, a majority women-owned and employee-owned firm dedicated to sustainable and impact investing, was founded in 2003 by ESG pioneer Geeta Aiyer. Rosemont partnered with Boston Common in 2016, acquiring a minority stake through its third and final private equity fund. During its collaboration with Rosemont, Boston Common achieved several notable milestones, including nearly doubling its assets under management, expanding its global client base and hiring Allyson McDonald as its Chief Executive Officer.

“We have tremendous respect for the team at Boston Common and have greatly enjoyed our working relationship,” said Brad Mook, Managing Director at Rosemont. “Boston Common’s reputation and tenure as authentic ESG investors, along with its solid investment track record, position it well to continue its growth. While we would have liked to remain partners indefinitely, our legacy fund structure requires an eventual exit and is a key reason we have since transitioned our investment model to permanent capital. We wish Boston Common and AMG well in their new partnership.”

Ally McDonald, CEO at Boston Common, said, “Rosemont has been an invaluable partner to our firm since its investment in 2016. Rosemont’s industry knowledge, robust network and sounding board approach have been consistently helpful in many areas of our business, and we appreciate its support over the past several years.”

Terms of the transaction were not disclosed.

About Boston Common
Boston Common is a boutique global equity investment firm and a leader in global impact initiatives dedicated to the pursuit of financial return and social change. Boston Common was founded in 2003 and is majority women-owned and employee-owned. The company manages active, long-only ESG strategies in U.S., non-U.S. and global equities and had $3.9 billion in assets under management as of December 31, 2020. For more information visit