The evolution of maritime networks is influenced by the search for productivity gains which generates important geographical concentrations. This phenomenon is explored in this paper with a particular focus on the shipping lines’ strategies. The analysis of the shipping lines’ transport capacities evolution within the period 1994-2002 confirms the stagnation of the port traffic concentration trend. However, another phenomenon of geographical concentration is going on at the level of individual shipping lines which reflects new strategies implemented by shipping lines during the last decade.