The company told the Korea Stock Exchange that the ships will be built at an unnamed yard up to March 2016.
The move is part of its ongoing effort to expand services.
It ordered four post-panamax, 7,300-car-equivalent-unit (ceu) newbuildings last year and has said it intends to keep ordering three or four new ships every year.
The owner has also bareboat-chartered four 6,500-ceu newbuildings to be delivered in 2015 from an unnamed Korean shipping fund.
Currently,
