Stagwell Group, the marketing investment group headed by polling guru and former Burson-Marsteller CEO Mark Penn, has purchased preferred stock in global independent agency Finn Partners.

The private equity fund's preferred share investment in Finn Partners carries future conversion rights to a minority interest in the firm, according to the agency in a statement. As a result of the deal, Penn now joins Finn Partners' board. No other changes in Finn Partners’ management, structure or operations will occur, according to the agency.

Finn PartnersFinn Partners founding partner Peter Finn told O’Dwyer’s that bringing on a minority investor was something he’d “wanted to do for quite some time.”

“We’re on track to becoming a top global agency, but we’re still far from where we need to be, and for some time I’ve wanted to bring in a minority investor to help accomplish that,” Finn told O’Dwyer’s. “What was important to me was to find an investor who was willing to take minority position and was willing to do it on terms that worked for us, and Mark was willing to do it on terms that made sense to me. He firmly understands our business.”

Finn told O’Dwyer’s that he and Penn attended high school together and have known each other for 45 years.

As a result of the investment, Stagwell and Finn Partners will also launch a new jointly-owned PR agency titled Wye Communications. Wye will hold multiple purposes, serving as a conflict shop for Finn Partners and slated to become a home to some “significant accounts” that Stagwell will bring to the table, according to Finn.

Wye will initially maintain offices in New York and Washington, D.C. Finn Partners will provide office space for Wye in the agency’s existing offices.

Stagwell, which was established last year after Penn’s exit as EVP and chief strategy officer of Microsoft, has been in the midst of a purchasing frenzy. The investment advisory shop in January acquired a majority stake in New York-based digital agency Code and Theory, a deal that followed Stagwell’s October 2015 purchase of PR and public affairs firm SKDKnickerbocker, and its November acquisition of Nielsen’s National Research Group. Former Microsoft CEO Steve Ballmer is a Stagwell investor.

Finn Partners in August acquired Portland-based agency Lane PR, and in July picked up Washington, D.C.-based branding and marketing services shop Greenfield Belser. The New York-based agency also acquired San Francisco-based tech agency Horn Group last year.

Finn Partners in 2015 accounted for nearly $71.5 million in net fees, revealing 35 percent year-over-year growth.