Raillard and Mokart joined BBH in April 2001 from CLM/BBDO in Paris.
While at BBH the pair created "Champagne" for Xbox as well as "mosquito".
Most recently they created the Frank Budgen-directed Levi's Worn Jeans campaign showing people rubbing themselves against a variety of surfaces.
During their year at CLM/BBDO, Raillard and Mokart's portfolio included work for Pepsi Europe, FedEx Europe and a campaign for Brandt kitchenware featuring people abusing their old machines, which also won a Cannes gold Lion. They created Robbie Williams' Rock DJ promo, which showed the star stripping off his skin.
Raillard and Mokart said: "John Hegarty is the best creative director we've worked with. But going to California is a way to improve ourselves by discovering anther culture. As a creative team we believe it's vital to keep on opening our minds."
John O'Keeffe, BBH's executive creative director, said: "Nobody thought they'd be here for years. They've done some fantastic work and they've added a Gallic flair to the place."