I have got a single WordPress installation.

I am using multiple domains for local languages, based on the domain I display translated text within the same theme.

domain1.com for English
domain2.de for German
domain3.it for Italian

Domains are pointing to the same directory on server, as I mentioned WordPress is single installation, so user database is shared (or to be precise: there is only one database for all domains).

Is it possible to make users logged in to all domains when they sign in to any of the domain in this chain?

Like:
user signs in at .it domain, but then I recognised him as German speaking visitor, so I have redirected him to .de domain. I would like to keep him logged in.

How to do that? 🙂