Changing job with approved I-140

[Visitor1183]

Hi all,

I got my I-140, with Employer A, around 1 month back (Oct 6 2017). My current H1-B visa is valid till 5/12/2018 and my 6yrs of H1-B are ending at this time as well. I am planning to join Employer B in a month's time. Need some advice on the best course of action here?

1. Shall I apply for H1-B extension with Employer A and join Employer B after H1-B extension is approved or shall I join Employer B now and get H1-B transferred? If I get my H1-B transferred will I get my H1-B validity till 5/12/2018 or will I get a validity beyond 5/12/2018 with my approved I-140 with Employer A?

2. As per my current employer's policy, they will withdraw I-140 petition 60 days after termination. Will this affect my priority date if my new employer decides to file PERM and I-140 sometime later since my I-140 has been approved for less than 180 days?

TIA