Transfer Employee from One Company to another one with Single Business Group setup

Hi All,

I have group of employee's which I want to transfer from one company to another one, so that there employee number will be changes and assignments Payroll, Grades job will be changes accordingly where we have a just one business group defined in system. So which method is suitable Terminate the employee from old company and rehire him in new company or Just update the employee number and assignment details.

Please provide the details with Pros and cons.

Thanks