A.P. Moller-Maersk A/S, owner of the world's largest container line, said mergers like the combination of its three main Japanese rivals provide relief to an ailing industry that has been characterized by over-capacity.

Nippon Yusen KK, Mitsui O.S.K. Lines Ltd. and Kawasaki Kisen Kaisha Ltd. said Monday they plan to merge, giving them control of 7 percent of the world's container-shipping trade. Its the latest example of industry measures to create scale in an effort to adapt to a world in which freight rates have been under pressure since 2007.

Soren Skou, Maersk Line's chief executive officer who also runs the Maersk group, said last month the Copenhagen-based company will stop buying new ships and instead try to expand through takeovers.