Annie Longsworth, founder/CEO of The Siren Agency CSR and social impact shop, is joining RF|Binder on Oct. 31.
She'll lead the RFB|Siren division as well as the independent firm's newly opened San Francisco office.
Longsworth launched Siren in 2015 after a three-year stint as CEO of Saatchi & Saatchi S.
Earlier, she spent nine years at president of Cohn & Wolfe San Francisco, launching and leading the WPP unit's sustainability practice.
Longsworth who is deft at insight collection, strategic discovery and social storytelling, has counseled Caesars Entertainment, Coca-Cola, Johnson & Johnson, Jackson Family Wines, American Express and Tom's of Maine.
The addition of Siren bolsters RF|Binder's commitment to working with what it calls purpose-driven brands.
"In the last several years, we have seen a significant shift in the value businesses, consumers and the investment community place on social and environmental impact. RFB|Siren is our response to that growing demand," said Amy Binder, CEO of RF|Binder.