The agency becomes part of Publicis Consultants, the name given to MSL's PR business in France.
Domaines Publics has 20 full-time employees and revenue last year of €6.4m (£5.62m, $7.4m), according to MSL. Major clients include Engie, Bouygues, Suez, Sodexo and Carrefour.
Domaines Publics was set up in 2004 by Jean-Michel Arnaud and Steven Zunz, who remain with the company in the new roles of vice president. Catherine Gros, also becomes a VP.
Arnaud began his career at McKinsey and Zunz as a parliamentary attaché for numerous elected officials. Arnaud is a foreign trade advisor to the French government, and Zunz this year authored the book 'France for sale? Put an end to the fear of foreign investments'.
They will work under Clément Léonarduzzi, executive chairman of Publicis Consultants, who took up that role eight months ago following the acquisition of his 12-person firm. Publicis Consultants has 175 employees in France.
MSL global CEO Guillaume Herbette said: "MSL continues to deepen our expertise around the world, particularly in core global practice areas like public affairs that are essential to providing influence and building impact for our clients locally and globally."