Is the pension from the Engineers Syndicate permissible (halal) if the Syndicate deposits funds in a usurious bank, knowing that the amount to be disbursed will exceed the amounts paid after a certain period?

The basic principle is that it is impermissible to subscribe to a retirement system that invests its funds in usurious banks. However, since the practice of engineering necessitates membership in the syndicate, and the pension system is mandatory, there is no harm in subscribing. It is permissible to benefit from what was paid in, and from any surplus if it is a cooperative pension, with the obligation to dispose of the percentage of usurious interest by spending it on public welfare and charitable causes. This can be done by consulting the specialists in the syndicate to ascertain the percentage.