LONDON—Finn Partners, the firm founded in 2011 as a spinoff for leading independent Ruder Finn, is continuing its international expansion with the acquisition of Johnson King, a UK-based technology specialist that also operates offices in France and Germany.

The deal follows acquisitions in the US—including Washington, DC-based Widmeyer Communications and most recently New York boutique gabbegroup—and the opening of a Finn Partners office in London 18 months ago.

That office, which started under the leadership of Chantal Bowman-Boyles with one employee and a single client, has expanded to a staff of about half a dozen and a roster of clients—many of them shared with the US operation—spanning consumer, education, and social issues in addition to tech. Johnson King, meanwhile, has a staff of around 20 and fee income of $3 million, almost all of it in the business-to-business tech sector.

Johnson King’s senior management team—led by Mike King, Claire Ayles and Flora Haslam—will all continue in their current roles, and the firm will continue to operate as Johnson King, a Finn Partners agency.

Both King and Finn Partners founding partner Peter Finn cited the cultural fit between the two firms as critical to the deal. Says Finn, “Very important to us was the culture, and the focus on being a great place to work, which has been part of our mission since we launched.” Both firms have won Best Agency to Work For honors from this publication in their respective markets.

Adds King, “We talked with a number of firms, and there is no doubt that Finn Partners was the best fit. It was important for us to find a partner that placed the same emphasis we do on the work environment, and on enabling people to express themselves and be creative.” In addition, he says, clients have increasingly been looking for support in international markets, and Finn’s strength in the US and ambitious growth plans will create new opportunities for both employees and clients.

The acquisition means that Finn Partners now has 350 employees in 11 offices around the world, and Finn says the expansion is likely to continue, possible including additional acquisitions in the UK to strengthen other practice areas.