To imagine the world without the presence of internet is almost impossible. Inside internet, the internet portals sector has a determinant role because they are the most visited adresses and that wich the clients have more contact. Instead of this important position, the sector future is not clear because of the absence of business models efficient enough to produce profit. Beside this scene, a new competitive reality appears. The business world doesnt compete anymore only in na atomistic way, the competition happen between companies networks. Our research tried to find out how works the competitive environment of the internet portals sector and what are the strategic implications of the network of alliances that these companies have over this environment.