Is the diminishing participation in housing loans, where the institution pays for the apartment and collects monthly installments from the employee for a specified period with the property mortgaged, permissible (halal)?

In this matter, a distinction must be made between two situations:

First: If the institution pays the price of the apartment as a loan to be repaid with an increment, this is impermissible because it involves a loan that brings a benefit.

Second: If the institution buys the apartment and takes possession of it, then sells it to one of its employees for a price higher than what it paid, and the price is paid in installments. This is permissible and is called Murabaha sale. Mortgaging the apartment with the institution until the price is paid is permissible for security purposes and has a basis in Islamic law, based on the Almighty's saying: (And if you are on a journey and find no scribe, then a pledge taken into possession) [Al-Baqarah: 283], and due to the action of the Prophet, peace and blessings be upon him.