Easy the company A 'lays off' 20 employees and company B 'agrees to hire' 20 employees at the same salary. You present it to the employee as a yes/no choice, you want to work in the new company or not at all. It often saves the laying off company from paying any form of severance and is only modestly disruptive on the lives of the employees. (although at the hiring company you have to manage these people who come in really angry/confused.)