Filing H4 EAD Extension based on previous Employer I140 Approval

I have I 140 from my previous employer and H4 EAD which is valid for 5 months.

I have changed my employer and have started perm filing. New I 140 approval will take 6 months or more.

Can I file an H4 EAD extension based on the previously approved I 140. I have worked for my previous employer more than 6 months after I140 approval.

Please advice on this.