I am currently on H1b visa and working full time for a company.effective Jan 1st 2012 my company will be merging with 3 other regional companies to form one company and will also have a name change. my i -797 has my current company name on it.my HR told me that during the merger my company tax id no will change.

1. should my company file H1B Amendment or new h1b petition? if so what is the time frame to do that.should it be before jan 1st or can it be after jan 1st.

2. if they need to file new h1b petition will it come under the cap status?
The corporate structure of my company is like,we have a national company and 8 regional company but the regional companies are considered independent companies but from Jan 1st 3 regional companies will merge to form one company with a diff name.