This paper was prepared as a background note for a discussion held at the OECD in June 2015 on competition issues in liner shipping. It discusses the main developments and competition issues in the sector, namely, regulation in different countries, the role of liner shipping consortia and strategic alliances, the trend towards horizontal and vertical integration, the implications of developments in liner shipping for ports, excess capacity and potential implications for competition, issues related with exchange of information and price signalling.