Is it permissible for an employer to compel employees to delay the performance of the obligatory and supererogatory prayers until after official working hours?

The owner of the company is not permitted to prevent employees from performing congregational prayers, nor to compel them to delay them beyond their prescribed time. By doing so, he exposes himself to divine punishment. As for delaying the supererogatory (Sunnah) prayers, there is flexibility in this matter. If they cause a delay in work, there is no harm in restricting oneself to the obligatory (Fard) prayers only.