Recently a friend of mine has received a stock buy offer from its company. The company offered to sell a specific amount of the company shares with a nice discount rate, because he was in a critical and irreplacable position. Everything is fine up to this point.

However, there is a ridiculous clause in the agreement: without any specific lime limit, if the employee quits job or the company fires him (event after 10 years), he will be required to, enforced to sell its shares back to company!

Is such a clause legal or against the priciple of private ownership? or can this be called stock buy offer at all? I guess you did not see such a nonsense before. Thanks.