MLO
Ocean freightMain Line Operator
A large shipping line that runs the long-haul trunk services between major ports.
In practice
Used in Southeast Asia to distinguish the deep-sea carriers (Maersk, MSC, CMA CGM, ONE) from feeder operators that shuttle boxes to and from the hub. An MLO booking covers the full trunk voyage.
Seen in the wild
Feeder from Belawan connects to the MLO vessel at Singapore.