L1A (Individual) to EB1-c Greencard

[JavaJack]

Hi,

I have L1A (Individual) valid for 1 year and company plans to start EB1-C Green-card soon. I will have attorney for this once process starts.

I am curious to know what would be fasted way to get Greencard. Can I-140 and I-485 applied simultaneously while on L1A? What timeframe I should be looking at for completion of all stages?

[JavaJack]

Could someone help, please? Appreciate your time!