DFDS said it finalised an order for up to six ro-ros at Sinotrans and CSC’s Jinling Shipyard in China.

The Danish shipowner said it placed the order for two firm 6,700-lane-metre vessels and options for four more.

The firm pair will be delivered at the beginning of 2019. The company is paying DKK 1bn ($151m) for the duo, with more than half of the amount due upon delivery. The price tag suggests the full series could cost $453m if DFDS exercises all options.

“The order is part of DFDS’s ongoing fleet renewal to accommodate the growth of our freight customers, increase operational efficiency and reduce the environmental impact,” the Copenhagen-listed company said.

The ro-ro freight ships will carry about 450 trailers.

With the order, DFDS is increasing the ship size in use in its North Sea network.

“The larger size of the new ships will significantly decrease unit costs as well as the environmental impact per transported unit,” DFDS said.

The ships will be built to the International Maritime Organization’s Energy Efficiency Design Index standard and will have scrubbers and ballast water treatment systems to meet regulatory requirements.

DFDS says its DKK 1bn projection for investments in 2016 remains unchanged.​