Reg Employer Change during 140 status

[santoshk.kumar24]

I have my PERM (Labor) approved and filed I-140 in Mar 2011 and in process (Not approved yet). All this is done by Company A (consultancy firm).

Now Company B (Large Company) is interested in my H1 transfer and willing to process my GC fresh after reviewing 1 year of performance. I want to go with them. Dilemma is I am in the middle of I-140 approval with company A. I am hoping to salvage the current I-140 process to retain priority date and port it to company B later.

If i go for H1 transfer with company B right now (before company A's i-140 is approved)......

1. Can I still continue with my current GC process pararlley with company A, until i-140 is approved and then port it to company B so the priority date is retained?

2. Is company A obligated to stop the i-140 process by any law? (Since they will no longer hold my H1?)

3. Assuming i go ahead with the H1 transfer to company B, What all i need to take care before the H1 transfer happens. (Also, planning to visit India after approval of H1B transfer to company B)

Note: Not in a position to wait until i-140 is approved for H1 transfer.

At this stage am not sure what the choices I have are and what is the best strategy I should apply.

Please Advice.