Yes, but the I-140 is likely to be withdrawn.
Your employer needs to retain an experienced immigration lawyer to review all the facts, advise them, and handle the case. Your employer can find one through http://www.ailalawyer.com.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
If you also have a Form I-485 Application for Adjustment of Status pending, and it has been pending for over 180 days, you may change employers and it won't matter if your old employer withdraws the I-140, as long as you are still working in the same or similar occupational classification.
You can use the priority date to get another H1.
Business Immigration Attorney. For H, L, J, EB5s, PERM and EB1/2/3 Petitions. Call 800-688-7892 or visit www.ImmigrationDesk.com. Law Office of Anu Gupta. The advice suggested here is for general information only and not to be construed as legal advice.