The shipping company, which is a joint venture between Erik Thun and KG Jebsen, will take delivery of the dual-fuel cargoship in 2016, brokers said.
The first 7,200-dwt ship was ordered in February 2015 for delivery this August. There was one option attached.
The vessels are ice class 1A, with Wartsila engines fed by a pressurised type LNG tank.
No price has been revealed.