What you do is email their help or business contacts and ask them for the person to talk to about 3rd party submissions.

Then you ask those people about the submission requirements, you will normally have to sign an NDA with them, then you can send them your product demo and talk to them.

You can let them know that your game is almost done, but the advice Ive heard is to still call it a demo or something similar because some people dont like to work with people who have projects that are too rigid and cant change to the publishers liking if necessary.

-Geoff

Well, me and my team have finished our premier title, but i'm having trouble finding a publisher. I have found many publishing sites but none tell me how to submit my product. The only publishing sites that tell you how to submit your game are the lower end ones, like e-games, and expert software. Where can i find information on Publishing opportunities with companies like Activision, 3D0 etc.??????

Try emailing the support email and ask them who you can contact about publishing a game

eg. support@activision.com