Moving during H1B extension based on approved Form I-140

Caller: I have completed my 6 year on H1b, im still on H1, my employer has filed my I-140 for my GC, my I-140 is approved, can I change my employer now?
A: Ok, your I-140 is approved; did your extension get approved?
Caller: My extension not been approved yet
A: Ok you can change employer, let me tell you how it works, you don’t have the AOS (Adjustment of Status) filed right? The I-485 has not been filed right?
Caller: No, I-485 has not been filed
A: I will recommend to at least clear that extension and then you move to the other company, or the company A with which you are working with right now. Maintain your I-140 and you go to company B in the transfer you can go ahead and do the extension, but the extension has to be filed and approved before the I-140 gets withdrawn. So if you leave the company now and you go and do an extension with another company and I-140 have been withdrawn you wont get it. But once – it has already been approved and its extended, then even if they withdraw the I-140 you can continue on the H1B. However, as soon as you get to company B I will recommend you to file a new Labor Certification and a new I-140, so down the road your able to go ahead and get another extension. Hope this answers your question.