I am in the 5th year of my H1. My current employer has filed for my PERM under EB-3 category since I did not have 5 years experience before (EB-3 has 6 years backlog though EB-2 queue for me is current). I want to know is it possible to wait for I-140 approval, get 3 year extension with current employer and then switch jobs? Will I be able to get 3 more years on H1 with future employer?
It is possible and common for employer B to get H-1 extension based upon an I-140 approval of employer A. You need to speak about the details with a lawyer.