Markosia is a British comic book publisher, founded by Harry Markos in 2005. Their website can be found here; https://markosia.com/
They have an open submissions policy that can be found on their website here; https://markosia.com/contact/submission-guidelines/
Markosia encourages submissions from artists and letterers, however if you are a writer, you will need to team-up with an artist to put together a project proposal.
The company operates on a profit share basis, taking a portion of the profits, and allowing the rest to be divided up between the creators.
Markosia’s printed books are all at least 40 pages long. Which means that individual issues usually receive digital only releases, and then the story is collected together in a trade paper back which is printed.
If you’re just starting out in the comic book industry, maybe with a few small press projects already under your belt, then Markosia is a good publisher to approach.