Second; One of the AI companies will always take the same production as the one you choose
at the setup.So if you want to avoid competition choose something you are not going to produce
and research something you like to produce before building any idustry.

Thank you very much for this useful information! Last time, I tried my best to make the enemy go bankrupt for being able to buy his shares, and was wondering why it just didn't work. The developers really did an awful job there!

But what exactly do you mean when saying that the AI would never "lose" any money?

The problem I have with the AI is that I actually seek a challanging game with an AI that realistically simulates human players. Most of the winning conditions are quite strange, so I always play with the goal of owning a certain amount of money. When my enterprise is big enough, i can simply sell all of my shares and win the game. But the AI never does that, so it feels like cheating when I do it! But what you are saying sounds like the AI cheats too anyway. :D

The best game you can find is the capitalism lab. Search net. There is no steam.