H1b extension based on I140 approved from previous employers

[vj28]

Hi 
My I140 is approved with Company A and based on the I140 (priority date of aug 12) I have already got an extension of my H1b (beyond the 6yrs) for 3 years which ends in Jan 2017. 
I am planning to change to Company B, based on approved I140 from Company A how much H1B extension will I get. Do I get another 3 years ? 
If for some reason, i am not satisfied with Company B and I plan to move to Company C before B files for my PERM&140, am I eligible to receive another 3 years H1B extension based on the approved I140 from Company A. 

Please advise.. 
Thanks

[pontevecchio]

Based on an approved I-140 you are eligible to get 3 year extensions.