H1B transfer while H1B extension is in progress

My H1B Extension is in progress in premium processing and My current I-94 is expired.

Is It possible, another company file a H1B transfer while extension is in process with uscis from current employer.

Is there any risk involve.

Thanks in advance !!!

Better to wait as Premium Processing takes 20 days or less…

What if I get REF …my 15days pp time is aboit to expire on 21dec 2013…i am expecting response from couple of days…