Publicis Groupe has acquired Swedish mobile agency Monterosa in a bid to boost Bartle Bogle Hegarty's mobile credentials.

BBH and Monterosa have already been working closely together for more than a year. The two agencies teamed up in Singapore to work on Axe, creating the pan-Asian "Dare" app that challenged men to get out of their comfort zone and approach women on a daily basis.

Monterosa's headquarters are in Stockholm, but the agency -- which was founded in 2009 and has 30 staff -- also has offices in New York and Singapore, and plans to open a London office next year. The agency will remain free to work with clients that it does not share with BBH. Monterosa clients include Google, Mercedes Benz, Samsung, Vodafone and Carlsberg.

Carl Norberg, one of the agency's founders, will report directly to BBH Group CEO Gwyn Jones. Mr. Norberg said, "BBH is a good strategic partner because we share a philosophy. They have extraordinary creativity, and a human side that I'm impressed by . It's the sort of company I want to build. We were approached by other companies but BBH was the absolute top of our list." Those other companies included both venture-capital firms and other agency networks, he said.

Mr. Norberg said that talks with BBH had started even before July, when Publicis Groupe bought the remaining 51% stake in BBH that the France-based communications group didn't already own. The terms of the Monterosa deal have not been disclosed.

Mr. Jones said in a statement, "Mobile ads can be uniquely useful and pertinent -- but they can also be perceived by consumers as disruptive. It's vital that we help our clients develop campaigns that are not just technically seamless, but also friendly and relevant. ... We're very excited about the potential for this strategically important move."

Johan Hemminger, CEO of Monterosa, Stockholm, said in a statement, "Our two companies share a passion for producing highly creative, disruptive ideas with a dedication to craft. This deal will enable us to take our work to the next level."

Monterosa was founded in 2009 by four Swedes and in 2011 at the Cannes International Festival of Creativity won a Gold Cyber Lion as well as a Bronze and a Silver Lion for Mini Getaway, which encouraged iPhone users to hunt for a virtual car. In the same year, the agency also won a Silver Lion in Titanium for its work on Swedish Armed Forces.