The ruling on selling shares in a riba (usury or interest) company

Question:
A man invested in a riba (usury or interest) company before he knew it was a riba (usury or interest) company. When he found out, he was confused about the shares: should he sell them to another Muslim, or should he leave them? It is known that the company does not accept buying them back from him.

Answer:
This is, as we mentioned, a case of negligence. It is obligatory for a person to know about a thing before he enters into it. It was obligatory for him to study the state of this company: what is its system, is it a valid system or not?
As for his taking the risk and entering without knowing, this is not permissible. Now that it has become clear to him that it is a riba (usury or interest) company, investing in it is forbidden. If he is able to withdraw his capital, it is obligatory for him to withdraw his capital, relinquish these shares, and take his capital. If he is not able to do so, he waits until it becomes easy for him to take his capital. As for selling them while they are riba (usury or interest) shares, that is not permissible.