SONY says it's "disappointed" not to be working with Disney on future Spider-Man films.
We might not see actor Tom Holland in new Marvel movies because a fresh deal can't be reached over the character.
The film rights to the superhero are owned by Sony - but he could appear in movies like Avengers: Endgame due to a deal between Sony and Marvel Studios - owned by Disney.
Sony says it hopes things "might change in future".
In a series of tweets, Sony thanked Marvel Studios president Kevin Feige for his "help and guidance" with the franchise.
Feige played a big creative role in the last two Spider-Man films, starring British actor Tom Holland, and successfully integrated the webslinger into its multi-billion dollar Marvel Cinematic Universe (MCU).
What's going on with Spider-Man?
Spider-Man is a Marvel comic book character - but in 1999 Sony bought the film rights for the superhero.
Sony made five films of its own featuring the character - three with Tobey Maguire and two with Andrew Garfield.
In 2015 the studio struck a deal with Disney and Marvel Studios, to bring Peter Parker and his alter-ego into the MCU.
The deal meant Disney would co-produce and share profits from films featuring Spider-Man.
Since then he's been in five Marvel movies:
Captain America: Civil War
Avengers: Infinity War
Spider-Man: Far From Home
What does this mean for new Spidey films?
Radio 1 and 1Xtra's film critic Ali Plumb points out that Tom is still contracted to Sony for two more films so "this doesn't mean we're not going to see him anymore" but the movies might look different.
"There's more of a risk for these new, only-Sony Spider-Man movies not being as good as previous Disney-made Spider-Man films."
But it could be an opportunity for Sony to be more "adventurous" and "edgy", Ali says, even if they can't reference other MCU characters.
"They will be forbidden from doing so because they don't own the rights to any of those Disney Marvel characters."
That's Iron Man, Captain America, Thor, Hulk and the rest.
Entertainment website Deadline has reported over the last few months that Disney and Sony were "unable" to reach new terms for funding of future movies.
And it was noticed at Comic-Con last month Marvel's announcements for its next phase of films and shows failed to include Spider-Man.
How is the Marvel world reacting?
Actor Jeremy Renner, who plays Hawkeye, has posted on Instagram, asking for Spider-Man to be returned to Marvel.
And Ryan Reynolds, who plays superhero Deadpool, answered a fan who'd asked if they'll see a Spider-Man and Deadpool movie saying "You can. But only in my heart".
The split between Sony and Disney also has people reacting online, from anger towards Sony, to fans who hope Tom Holland is OK.
Some have been using the hashtag #BoycottSony, saying they don't want to watch films coming out this year by the studio because of the Spider-Man announcement.
#SaveSpidey has also been trending in the UK this morning.
And a lot of fans have been sharing an old tweet from Stan Lee, the co-creator of Spider-Man who passed away last year.