Ash-Shaykh Ahmad an-Najmi, Rahimahullah, was asked the following question,
Is it permissable to purchase houses which the banks have been investing in its establishment and which its payment is done through an installment plan upon profit?
This issue has some sort of complication to it. It could be said that the person who is purchasing with his own money by which he is paying for the price in advance and not in delay, (that) then there is no problem in this. (This is) since the sin is upon those who initially acted upon this in establishing these houses and its likes. And it could be said that what is better is to leave it off. If it is possible for a person to find other than it, then it is better to leave it off. However, when there is a need, then from what is apparent (to me is) that it is permissible In shaa’ Allah.