Change employer with approved 140

[clkarthik]

Hi,

I work for company A and have a very good offer from company B.

My current GC status:-
GC Filled under: EB2
Priority Date: August 28th 2008
I-140 approved Date: October 15th 2009
I-485 : Waiting for dates to become current.

H1 (8th year) extension based on 140 approval, valid until Nov 2012

Can I change from company A to B and port my priority dates ?

Thanks