go to the new company and do EB2 PERM

Since I140 for your old EB3 has been approved, you can go ahead and apply for a new EB2/PERM. Once this new EB2 I140 is approved, you can use the priority date of your old EB3 to apply for I485, and your new case is still EB2. This is my understanding, consult some good immigration attorney for details. GL