"The Manners of Downton Abbey," and more "Mr. Selfridge," "Poldark," and "Indian Summers" are also included
Longterm partnership deal unites companies behind "Mad Men" and "Doctor Who"
A partnership would allow the companies to share resources amid a changing industry
The titles will be available when the new streaming service launches next year
Starz signs on to distribute the upcoming season of the U.K. sci-fi hit in the States