H1B expiration/transfer

[aschandra]

Hi,
I'm on a H1B with company A. My 6 yrs of H1 expires in July 2010. I have a I140 approved with company A and my company filed for an extension of my H1 based on my I140 and got my H1 extended until April 2012.
I now have an offer with company B. Company B will start my GC process in June 2010. If company A revokes my I140 after I resign, will I still be able to work for company B until April 2012 with my latest H1?

Any quick responses are really appreciated.

Thanks.

[sk4ih]

Yes.
Approved extensions will not be canceled.

[aschandra]

Thanks. Also, does company B have to apply my GC right away or is it ok to do it anytime before 365 days of my latest H1 expiring (April 2012)?