The European Union removed the block exemption granted under Regulation 4056/86, to liner shipping companies to provide scheduled services on a collaborative basis effective October 2008. This has also been followed by the proposed P3 alliance with participation of Maersk, MSC and CMA CGM. This paper explores, the arguments adopted by the US Federal Maritime Commission, the European Commission and the Ministry of Commerce of China, in rejecting the case proposed by the P3 alliance. The findings of this paper will inform on understanding strategies adopted by major Competition Regulatory authorities in their interpretation of horizontal collaboration in the industry.