Stambler served for three years as manager of acquisitions at Magnolia and played a key role in the acquisitions of The Host, The Signal, and Jesus Camp.
He will jointly report to THINKFilm's head of US theatrical Mark Urman and senior vice president of acquisitions and business affairs Randy Manis.
The company has also promoted Michael Baker from director of acquisitions and development to vice president, and David Laub from Urman's assistant to manager of acquisitions.
'As our company elevates to the next level, it is crucial to fortify the ranks with smart and aggressive executives,' Manis said. 'Stambler's background and training - and the fact that he doesn't own a suit - make him a perfect fit for us as we begin to acquire bigger films and to co-finance and produce a portion of our slate.'
'Michael Baker's promotion to vice president was the result of years of dedicated service and enormous growth,' Urman said. 'With David, who has also come a long way with us, and with the addition of Ben, our acquisitions team is bigger and brighter than it has even been.'
THINKFilm's recent acquisitions inc lude the Sundance duo of In The Shadow Of The Moon and The Ten.