Rogers & Cowan CEO Tom Tardio is stepping down after 27 years at the helm of the entertainment PR powerhouse and is slated to join enterprise social software developer Socialtext as chairman in July.

tom tardioThe 63-year-old exec will take a chairman emeritus role with R&C as he advises the search for a successor. He took the CEO reins at R&C in 1991 from Richard Taylor and led the firm through its acquisition by Interpublic in 1998 (Shandwick bought R&C in 1987).

Waltham, Mass-based Socialtext has operations in Silicon Valley and is backed by private equity firm Bedford Funding. It provides social software for the enterprise market to power blogs, social networks, wikis and other tools for employees. Users include Meredith Corp., Symantec and NYU Stern, among others.

Tardio is already a board member of recruiting software company PeopleFluent, also owned by Bedford.

Paul Bloch is co-chair of R&C.