The only case I can think of where a feature film crossed over characters or franchises belonging to two or more different studios was Who Framed Roger Rabbit?
-- and it took a lot of effort to get studios like Warner Bros. and Turner Entertainment to agree to share their properties. Oh, and also there was Toy Story 2/3
using Barbie and Ken, something Mattel wouldn't agree to until after the first film was a huge hit. And Wreck-It Ralph
has done something similar with video game characters, although they're just cameos.
Of course, in all those cases, it was Disney's clout and wealth that was able to get it done, so if anyone could make it happen with rival space-opera franchises, it would be Disney.
There is the case of Freddy vs. Jason
, a crossover of New Line's Nightmare on Elm Street
franchise and Paramount's Friday the 13th
franchise. But that didn't happen until Paramount lost the rights to Jason and New Line acquired them. So that doesn't count as a real inter-studio crossover.