Mandate will fully finance the new venture - called gang of two - and will look to produce films written by Helm as well as shepherd projects by other writers and directors.
The first project will be a comedy focusing on the high-stakes world of high school speech and debate teams, said to be based on Helm's 'embarrassing' high school experiences.
David Posamentier and Geoff Moore will co-write the untitled comedy, and Matthew Milam will oversee the project for mandate.
'I've admired Zach's original voice ever since I first read Stranger Than Fiction and now even more having seen what he's created with Mr Magorium's Wonder Emporium,' Mandate's president of Motion Pictures Nathan Kahane said. 'He is an extraordinary talent and it feels great to be working with them in this new capacity.
'We appreciate the support and working relationship with Nathan, Joe Drake and their team,' Helm and Garavente said. 'The ideal projects for us are smart, absurd commercial comedies and we hope to become a viable asset for film-makers looking to get projects made here at Mandate.'
Helm began his career in Chicago theater and met Garavente when the latter served as his literary agent. They consolidated their creative collaboration on Helm's directorial debut, Mr Magorium's Wonder Emporium, on which Garavente makes his producing debut.
gang of two is represented by CAA and Hirsch Wallerstein Hayum Matlof and Fishman. Posamentier and Moore are repped by UTA, Kaplan/Perrone Entertainment and Colden, McKuin & Frankel. David Matlof negotiated the first-look deal for gang of two with Rob McEntegart on behalf of Mandate.