H1B transfer while 140 pending

[rahulsi81]

HI,
Need advice on my h1b immigration...was on H1B with Employer A for 6.5 yrs and had  I-140(passed 180 days mark)  also...
Moved to Employer B, have approved 797 and they have are also in process of getting new I-140 although pending.....

Can i switch to new employer C based on  I-140  from Employer A......will this be considered as Cap Exempt....or do i need Employer B  I-140  approved to make any move ?
Does this changes if Employer A has already withdrwan  I-140 ?

thanks