How long can we stay out of US after I-140 approved?

[sskssk]

Hi

My I-140 is approved and waiting for my PD to apply I-485. Meanwhile, I am planning to go back to India for about a year and will continue to work for the same employer in India and will come back to US. So, I wanted to know will this one year break has any impact on my approved I-140.

How long can we stay outside of US to keep the approved I-140 valid and active.

Please advice. Thanks

[txh1b]

I140 remains valid as long as employer keeps it valid.