Can my previous employer file for I140 after if the PERM just got approved

I’m new to this . My question may look too simple but I would appreciate any advice in this regard.

I am in my 2nd year of my H1 .

I had my previous employer A (consulting firm ) apply for my PERM back in Nov 2014(25th). But the project at the clients place got shelved in Dec.

After this happened , I took up a full time job and transferred my H1 to my current employer B

Looks like my current employer A is not likely to initiate the process until 2016.

So , here’s my question .

If the PERM applied by my previous employer gets approved in next couple of month , can request my previous employer to file for the I140(Premium) ?

If yes, in what circumstances ?

Note: My relationship with my previous employer is not the best but an okay one.

Please advice .

Any suggestion or advice is greatly appreciated .