time limit for refiling I-140 after 7th year H1B transfer

[bountyful]

I am in the 7th year of my H1-B and have an approved I-140. I have a job offer where the employer will do the H1-B transfer but wants to wait atleast 6 months before starting/filing the GC paperwork. Is there any sort of time limit within which this needs to happen so I can hang on to my old PD?

[pontevecchio]

NO.