No. You cannot. L1 is for intra company transfers. But If an employer sponsers H1 for u, u can change your status from L1 to H1. If your H1 is applied via COS(change of status) you can start working for differnet company once your H1 is approved. If its not COS and if it is CP(through consular process), you can either go back to India and get your stamping done or you can fiel pettion for amendement saying you are laready in US on L1 status and want to change to H1 in which case it depends on the USCIS whetehr to grant COS or not. For your information: This year’s H1 quota is already full and if your Company B the H-1B petitioning employer is cap-exempt then they can apply an H1 for you now also.