H1B transfer when extension is pending with approved I140

Hi,
My H1 extension after 6 years is currently in progress, haven’t yet received the receipt number. My I140 was approved a couple of months back. I am trying to move to another company. Can the new employer file a H1 transfer using my existing I140 or should I wait until I get my approval for H1 extension? Appreciate any inputs.

Thanks

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