The extreme case of this would be Poison Pills, so if that's allowed then I suspect you can contract for this as well.
Having said that this is the type of thing that is likely to get dragged in front of a judge, so the more foolproof way would be to retain 51% control or dual-class shares. Once you give up majority control to third parties, you can't really prevent everyone else ganging up on you and outvoting you.
Having said that this is the type of thing that is likely to get dragged in front of a judge, so the more foolproof way would be to retain 51% control or dual-class shares. Once you give up majority control to third parties, you can't really prevent everyone else ganging up on you and outvoting you.