PR firm Inkhouse sold to NYC communications heavyweight BerlinRosen

The deal will preserve the Inkhouse name and senior leadership for the Waltham-based firm

Inkhouse CEO Beth Monaghan is selling her company to New York PR firm BerlinRosen. She will remain with the company.Lane Turner/Globe Staff

Inkhouse chief executive Beth Monaghan just wrote the start of a new chapter for her Waltham-based public relations firm, by inking a deal to sell the firm to New York PR heavyweight BerlinRosen Holdings.

Monaghan stays on board under the new ownership, and has received equity in BerlinRosen as part of the deal. Also staying: the Inkhouse name, which dates back to 2007 when Monaghan and Meg O’Leary started the firm. And Inkhouse will hold onto its offices on Main Street in Waltham as well as in New York, Seattle, San Francisco, and San Diego. With 142 employees, including 60 in Greater Boston, Inkhouse is one of the region’s largest public relations firms. While it focuses on tech startups, Inkhouse represents other kinds of clients, too, ranging from Raytheon to Brown Brothers Harriman to Harvard’s Graduate School of Education.

Monaghan said the decision to sell — she bought out O’Leary’s stake in 2015 — was driven by a desire to offer more services to clients, not to cash out. She said she had looked for a possible partner for more than a year before a childhood friend of her husband’s connected her with BerlinRosen cofounder Jonathan Rosen. The New York firm has been on a growth spurt as of late, acquiring several like-minded agencies after an investment in early 2022 by private equity backer O2 Investment Partners. The financial terms of the BerlinRosen-Inkhouse deal were not disclosed.

“We don’t want to grow for the sake of growth but because of the opportunity that it affords our clients and our people,” Monaghan said. “We were getting to the point where we were going to be a $30 million firm [in annual revenue]. I was just looking around, thinking about the things we would like to do next.”

Now, as part of BerlinRosen, Inkhouse will offer services that it did not offer before, such as diversity consulting and public affairs work. The deal also offers an opportunity for Inkhouse to do more consumer-focused work, and hopefully provide more insight into how artificial intelligence can help clients tell their stories.

As a sole owner, Monaghan said she didn’t have access to the capital necessary to grow Inkhouse the way she wanted to grow it from here.

“BerlinRosen just had the exact capabilities that we don’t have,” Monaghan said. “Equally important, I just felt Jonathan and [cofounder] Valerie [Berlin] are two people who share our values. They’re trying to prove you could do well in business and do good in the world at the same time.”

Monaghan and O’Leary, who previously worked together at VC firm Charles River Ventures, launched Inkhouse in 2007, and targeted the next generation of tech firms that emerged after the dot-com collapse of the early 2000s.

O’Leary decided to leave in 2015. That prompted Monaghan to buy out her partner, which she calls the scariest professional move she has ever made, considering how much money she needed to borrow to make it happen.

But Inkhouse kept growing, essentially doubling its revenue over the subsequent seven years. And Monaghan gained more autonomy to dive into advocacy work, such as pushing for gender equity pay legislation. She also became a leading voice on workplace issues. Monaghan said she’ll continue to have latitude to speak out on issues of importance while under the BerlinRosen corporate umbrella.

“It was a risk for me,” Monaghan said of her activist work, “[but] if you don’t stick by your values when it’s hard, I don’t know if they’re worth anything.”

Rosen said he was attracted to Inkhouse in part because of its strengths in several tech fields, such as health care and climate. The acquisition, which was completed last week, brings BerlinRosen its first Boston-area office — although it already has clients based in this region including Boston Properties, WS Development, and BlueHub Capital.

“We’ve been so extraordinarily impressed by Beth and her team, by what they’ve built,” Rosen said. “This is all about retaining talent, developing talent, and investing for the future.”