H1 petition can be transfered while on L2

I am on L2(dependant of my spouse) and my employer in India filed my H1b in April,2012 while I was in India, and then I came to US with my spouse and H1b petition got approved in oct,2012. I haven’t been to India to get my H1 visa stamped. Can i transfer H1b petition for a new employer in US although petition was filed by an Indian employer.

If yes, how much time will it take to transfer my petition to new employer and what all docs I need to get my previous employer which are required by new employer to file my petition.

Any advise/suggestion is appreciated as If this cannot be done then I have to plan my trip to India to get my H1 visa stamped.

Yes, this can be done. A new employer can file a cap-exempt petition for you (aka H-1 transfer) along w/ COS from L-2 to H-1. Once approved, you can start working for new employer from the COS approval date.