IANAL, but it sounds like his threats are just piss and wind. I can't see how he has any rights, other than those of a minority shareholder and as a (former) sa

IANAL, but it sounds like his threats are just piss and wind. I can't see how he has any rights, other than those of a minority shareholder and as a (former) sales manager. On the other hand, you can sue him for acting as an agent without actual authority. Those hires and purchases he made that you explicitly vetoed? Invoice him, and watch him squirm. Tell him he can pay for them with some of his shares. But ask a lawyer first. If he keeps making noise, ask him if you can speak to his lawyer. He doesn't have one. No lawyer would advise him to make such stupid decisions (trying to roll a CEO with just 20% of shares, vague threats, etc). You have to buy him out eventually, or he'll be a recurring headache. It might cost more than 400k, as his investement has matured.