The founding partners of Slate PR have dissolved the publicity firm after 15 years, but are staying in business together with the launch of new venture, Apex Public Relations.

Run by Slate PR leaders Stephen Huvane, Robin Baum, Simon Halls and Andy Gelb, the new version of their company, which has “existed through several iterations for more than 30 years,” is open for business with fully staffed offices in Los Angeles and New York City. Fellow Slate PR partner Ina Treciokas is splitting from the rest of the group and will soon announce her next moves.

Per Apex, “the entirety of the partners’ clients will join them in the new venture” as will the “vast majority of the Slate employee team.”

Existing clients from the Slate PR portfolio include Jennifer Aniston, Ryan Gosling, Zendaya, Chris Hemsworth, Ryan Murphy, Julianne Moore, Emily Blunt, Lana Del Rey, Brendan Fraser, Russell Crowe, Anne Hathaway, George Clooney,...