Adding a receiver

[Dominik Werder]

Hello!

I've encrypted a large file and sent it over the internet.
After that I realized that it is encrypted with the wrong public key.
As far as I understand public key encryption it should be possible to  
reencrypt only the random session key for the symmetric cipher with the  
other public key of the receiver so that I don't have to retransmit the  
whole file.
Is something like that possible with gpg?

thanks and bye!
Dominik