According to Wall Street Journal and Reuters, Electronic Arts and UbiSoft are in preliminary talks or as they say “I would not say there's negotiations taking place, but we are having the kind of dialogue that you would expect of a large shareholder with the company". It is not clear what these talks concern, but I could make some wild guesses:
Firstly, they will test the waters on some ownership arrangements. It is very good setting for that because there are some high-ranking UbiSoft managers (there should be) involved in this dialogue, and they are also major shareholders. Impress these guys and the whole UbiSoft will move. Convince them not and the deadlock will remain.
Secondly, there will be discussion on possible cooperation. If direct approach fails, try to lure the partner to see possible benefits of joining forces. This has the added benefit of people of these two companies getting to know each other. However this could backfire too, there are some classic prejudices between the two sides of the great water.
Thirdly, if all else fails that are friendly gestures and mild manners. The only thing for Electronic Arts to do is to turn on pressure to make some changes in the UbiSoft board. Guillemot brothers have the power in company that goes well beyond their ownership. Last chance for EA to gain better hold in this situation is to, as a major shareholder, get their guy into the board.
I am guessing that this is the blueprint for the dialogue.