Multilangual TLD with session share

Hi Guys!

I'm trying to do a multilingual site with multiple domains for like www.example.com www.example.de www.example.hu

What is the easiest way to share session between these domains?

The user story is: -Storing the user's locale in the session, -If somebody comes to www.example.com with session locale de, then we have to redirect to the www.example.de domain.

Can you give me any sign?

Thanks!