GC filed with 2 employers and I-140 still pending for more than 2 years

[sathishp]

Hello, 

To give you a background, I have 2 GC processing through 2 different companies.

Company A:

My initial GC priority date is Dec 2009 and my I-140 and I-1485 was filed concurrently (normal processing - EB2) through company A back in April 2012. Immediately after my filing, the PD went back to 2004 and I-140 is still pending for more than 4 years. I was on L1B visa during this time through company A.

Company B: 

I changed my employer and changed my status to H1B back in 2013. A new GC was filed through company B in 2014. My I-140 was filed in Dec 2014 in normal processing (EB2) and it's still pending for more than 2 years.

My 6 years visa is already expired. I am only getting 1 year extension of my H1B every year. The question I have is - I am not sure why there is so much delay? Should I convert my I-140 to premium through company B? If my I-140 is approved through company B - will I be able to preserve my previous PD from company A? 

What is the risk - if my I-140 gets denied through company B?