The partnership will see New Regency help to finance the film, all the while allowing Ubisoft to retain creative control.
A screenplay for the upcoming movie, which will be produced by and star Michael Fassbender, is being developed immediately.
"Ubisoft chose to partner with New Regency because they are a talent and filmmaker-driven company, with the same independent and creative mindset that we have at Ubisoft Motion Pictures," explained Ubisoft's Jean-Julien Baronnet.
"Bringing aboard New Regency's renowned production and distribution expertise while maintaining our own creative and financial flexibility ensures that Assassin's Creed will be a high-quality film that respects the lore and fans of the video game franchise," he added.
The Assassin's Creed video game franchise has sold more than 30 million units since debuting in 2007. The next instalment, Assassin's Creed 3, will be released on October 31.
Officially unveiled in March, Assassin's Creed 3 will take place over a 30-year period in colonial America beginning in 1777.
It will be accompanied by PlayStation Vita spinoff Assassin's Creed 3: Liberation, which was announced at this year's E3 Gaming Expo.
Fassbender, meanwhile, recently starred in Ridley Scott's Prometheus and is currently filming Twelve Years a Slave with Steve McQueen.
He will reprise his role as Magneto in the X-Men: First Class sequel next year.
Watch a trailer for Assassin's Creed 3 below: