Hello. Technically, as long as your L-1A application is pending, you are still in legal status even after your I-94 expires. IF your L-1A is denied, then you have to leave the U.S. immediately (within 10 days, generally). For an EXTENSION of status, you are allowed to be employed for 240 days after your request is submitted. Take a look at this link:

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&rgn=div8&view=text&node=8:1.0.1.2.54.2.1.1&idno=8

Section 20 applies to you:

(20) A nonimmigrant alien within the class of aliens described in paragraphs (b)(2), (b)(5), (b)(8), (b)(9), (b)(10), (b)(11), (b)(12), (b)(13), (b)(14), (b)(16), and (b)(19) of this section whose status has expired but who has filed a timely application for an extension of such stay pursuant to §§214.2 or 214.6 of this chapter. These aliens are authorized to continue employment with the same employer for a period not to exceed 240 days beginning on the date of the expiration of the authorized period of stay. Such authorization shall be subject to any conditions and limitations noted on the initial authorization. However, if the district director or service center director adjudicates the application prior to the expiration of this 240 day period and denies the application for extension of stay, the employment authorization under this paragraph shall automatically terminate upon notification of the denial decision;

(b)(12) is for L-1 visas. They only issue that I would see is that your petition is actually a CHANGE of status not an EXTENSION of status, but I think it would be better for you if it was seen as a change of stauts because then it should not be 240 days limit but as long as the change of status is pending.

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