Is it permissible to distribute profits annually in the aforementioned Mudarabah and Inan company, or must it be at the end of the specified three-year period?

It is permissible to mix Mudarabah funds without the knowledge of the partners, provided that the agent is capable of managing all of them. There is no harm in taking Mudarabah funds from several individuals and adding the agent's own money to them. However, adding the agent's share of the profit to the capital is not correct, because the agent does not possess their share with full and stable ownership until after the division and liquidation of the funds and their delivery to their owners.