can unused H1 approval be used for transfer?

[SharmaA]

I have a unused H1 approval papers from company B (2006) that I couldn't get stamped due to some family issues. it is valid upto 2009. am based in India.

could this approval be used as basis for H1 transfer filing with company C now ?

or is a valid visa already stamped on passport a must for transfer filing ?

thanks for any help
-Arun