Did you see my edit?
I'm not particularly sure why you seem to think that these agreements that have been highly publicised don't exist. Yes Sony could do whatever they want with the Spider-Man film ip, but they decided to partner with Marvel, and of course there has been a degree of give and take from both sides as part of those negotiations. Sony would have put Tom Holland as Spider-Man in Venom if they had not agreed to any terms restricting what they do with the ip otherwise.
So the answer is no, there isn't any. Okay, cool.