The company will specialise in international publicity for major festivals and represents three films at Venice including Andrea Porporati's competition entry Il Dolce E L'Amaro.
The other Venice titles are Barbara Cupisti's Madri and Albert Maysles and Kristin Nutile's Sally Gross: The Pleasure of Stillness.
Tomassini is co-founder of the European Media Agency, which will continue its marketing activities while Silversalt PR specialises in international film publicity in Europe and North America.
Mooij has worked as a trade journalist and critic for Screen International, The Hollywood Reporter and Cineaste. She was also programme officer of the Goethe-Institut in London.
'Not only do we speak several languages, we create tailor-made media pitches for each individual film that will maximise its exposure in a particular territory,' Tomassini said.
'Claudia has a solid track record of handling press, events and red carpet appearances,' Mooij added. 'Combined with my editorial background this allows Silversalt PR to offer a full range of services, from writing marketing materials and translating to subtitling films.'