South Korea’s Daewoo Shipbuilding has received an order for 10 vessels from Maersk, the world’s biggest container shipping company, with an option for another 20 similar ships.

The entire deal is worth 4.1 billion euros and involves the South Koreans constructing ships that are larger than anything that has ever been built before – 400 metres long and almost 60 metres wide.

Maersk – which is part of the Danish shipping and oil group A P Moller-Maersk – wants to add the ships to its fleet which already exceeds 500.

They would ply the routes between Asia and Europe, which Maersk see as enjoying major expansion. Each would carry 18,000 containers, almost a third more than the largest ships currently afloat.

“You build ships for 25 years, so you need to take a long-term view, but even in the shorter term we are actually quite comfortable, and we will see growth of five to eight percent also in the Asia-Europe trade,” Maersk Line Chief Executive Eivind Kolding said.

Maersk put the price of each vessel at almost 140 million euros and said they would be delivered from 2013 to 2015.

The deal would be the biggest-ever order for Daewoo and its shares leapt 4.8 percent in Seoul.