Rittner (pictured) joins the company from Ipsos, where she was vice-president of the Social Media Exchange division. 

In her new role, she will help Basis to expand its US business with a focus on the West Coast.

The move follows the launch of the London-based company’s global healthcare practice in New York. Basis opened its Los Angeles office in 2016.

Rune Mortensen, chief executive of Basis, said: “Growing our commitment to the West Coast and Los Angeles is a natural fit for the client work we are already doing both in London and Los Angeles. As this work continues to expand, our LA office allows us to better service these existing clients while growing new relationships.”