http://h1bsupport.com/blog/3900/h1b-extension-beyond-6-years-explained-in-detail-with-faqs
My PERM got recently approved after 365 Days, but my employer has not filed
the I-140, can I use the approved PERM to file an H1B Extension for 1 year?
Yes, you can use an approved PERM to file the H1B Extension, please note
that the PERM filing date must over 365 days ago.