Is it permissible to deal with a company that guarantees fixed profits of 25,000 for 40,000, and refuses to specify a certain percentage of the profits?

The scholars are unanimous in prohibiting the تحديد (specifying) of a certain amount in a partnership (sharika), and that this condition invalidates it. Therefore, it is not permissible to participate in this company (partnership) that specifies a certain amount for the participant, and any justifications for this specification are null and void and are not to be considered.