Shareholders' agreements
Shareholders' agreements are relatively rare in companies whose stock is publicly traded, but they are prevalent in privately owned companies. That's because minority shareholders can create substantial problems in a small-company context, especially when they seek to sell or transfer their shares to third-party buyers.
To protect against potentially problematic situations, a shareholders' agreement can specify certain conditions under which one shareholder must sell shares to fellow shareholders or back to the company. For instance, some companies give the company the right of first refusal to buy back shares that pass to an heir after the death of a shareholder. Other agreements can force a sale based on other conditions, such as a merger offer or a change of control among corporate leadership.
The agreement will often set the amount of compensation that the selling shareholders will receive for their shares. In some cases, the payment the selling shareholders will get won't necessarily reflect the current fair value of the shares, but they will reflect a formula that all shareholders will have agreed upon when they initially signed the agreement.
Forced sales among shareholders aren't all that common, and in most cases, shareholders are happy to sell shares in situations involving acquisitions.