H1 Extension with previous company approved I140


Can you please help me in clarifying on this. I am working with Company A and having Approved I140. I completed only 4.7 years of stay in US including both L1B and H1B. Now i am thinking to switch to another company and so if i switch to other company now and i may get an year extension or 2 years extension with company B since i have approved I140. The question is, will i get extension OR apply for H1 extension next time again by showing the previous company A approved I140 with company B? How many times i can get extension when having approved and active I140? Please clarify me on this. Appreciate your help on this.