The Port of Manila is the largest seaport in the Philippines , making it the premier international shipping gateway to the country . The Philippine Ports Authority is government agency responsible to oversee the operation and management of the ports . The International Container Terminal Services Inc. cited by the Asian Development Bank as one of the top five major maritime terminal operators in the world has its headquarters and main operations on the ports of Manila . Another port operator , the Asian Terminal Incorporated , has its corporate office and main operations in the Manila South Harbor and its container depository located in Santa Mesa .