If you own part of the company you don't just give that up without there being express wording in the charter (or whatever contract/paperwork you used to create the company). The problem you have is that right now, you own 40% of nothing so you're going to pay the lawyer you talk to (rather than have them work on contingency).
I should also note that this seems like a weird time to leave a startup ... did you really think you could cash out in just two years? Perhaps you haven't been "invested" in some time?
If you own part of the company you don't just give that up without there being express wording in the charter (or whatever contract/paperwork you used to create the company). The problem you have is that right now, you own 40% of nothing so you're going to pay the lawyer you talk to (rather than have them work on contingency).
I should also note that this seems like a weird time to leave a startup ... did you really think you could cash out in just two years? Perhaps you haven't been "invested" in some time?