They inherited mixed shares of which the value has increased; how can they dispose of them?
Question

We inherited some shares in telecommunications, and we used to receive the profits; we disposed of 10% of them, and kept the rest. Is what we did correct? We want to sell the shares and get rid of them, and we do not know what the capital was. The price of the shares has risen, so what should we do?
Praise be to Allah.If the shares mentioned are mixed, because some of the company’s activities are haraam, or because the company deals with ribaa when lending (by depositing money with them) or borrowing money, then what you must do is get rid of them by selling them, and it is not permissible to keep them and do what you have been doing to purify the earnings, because the prohibition does not extend only to consuming the haraam riba (interest); rather it also extends to the transaction itself. That is because the shares are something held in common, and the sin of every haraam transaction involving the shares is incurred by all of the shareholders, as has been explained previously in the answer to question no. 83969.
With regard to the profits in return for unlawful activities that you acquired before coming to know of the prohibition, you may keep them and make use of them. But whatever came after you learned of the prohibition must be disposed of.
With regard to the rise in the value of the shares, it makes no difference. So you may sell the shares at their current value, then get rid of the haraam portion of the profits that was acquired after you came to know of the prohibition, whether it is 10%, or more, or less.
It says in Fataawa al-Lajnah ad-Daa’imah (14/299): Question: We fear Allah and hate ribaa. I had some money to invest, and it was invested in the electricity company, the Sabak agricultural company in Tabook, an agricultural company called Nadak, and the Kuwait Cement Company, and in a car company. I have heard a great deal of talk about these companies being involved in ribaa, but I cannot take any decision until I hear the facts from the Shaykh, may Allah reward you with good. If these companies do deal in ribaa, then what is the way to get rid of these shares and get my money back?
Answer: Firstly: With regard to any company that is proven to deal with ribaa, either by accepting it or giving it, it is haraam to buy shares in that company, because that comes under the heading of cooperating in sin and transgression. Allah, may He be exalted, says (interpretation of the meaning): “And cooperate in righteousness and piety, but do not cooperate in sin and transgression. And fear Allah ; indeed, Allah is severe in penalty” [al-Maa’idah 5:2].
Secondly: If someone previously bought shares in a company that deals with ribaa, then he must sell those shares and donate the interest (ribaa) to charitable causes. And Allah is the source of strength. May Allah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.
Dr. Muhammad al-‘Usaymi (may Allah preserve him) was asked: I have held some shares in the Sabak company since it was founded. With the spread of “share fever” in society, I remembered them and I asked about the company, and they said that it deals in ribaa. As you know, the cost of subscribing was low, and the shares earned profits in the form of cash and more shares; their value now is a little more than three hundred thousand riyals. Please advise me, may Allah reward you.
Answer: If, as you say, you were unaware of the way in which the business is run, you should sell the shares and you may keep the price, and there is no need to purify it [by giving some in charity]. There is nothing wrong with you keeping their price and wa la tatheer. You should give zakaah for one  year on the previous profits that you did not collect. May Allah guide you.
End quote from the Shaykh’s website.
And Allah knows best.