Why would an employer pay for the full social premiums, so also the employee part?
Sometimes this has been part of the salary negotiations in which case employees can ask for this benefit if they know it is possibile.
In other cases, for example in case of net salary agreements, it is profitable for the employer to pay the full social premiums. In that case gross and net salary will be closer together if there is no deduction of employee parts in social premiums. So gross salary and also the total social premiums will be lower in comparison to a calculation with the regular employee and employer contributions. This might save the employer several thousands in wage costs per employee per year.