The Seoul-listed company said the ship was costing around KRW 59bn ($52m) and would be delivered by May 2017.
In February KSS Line disclosed that it had ordered a single 38,000-cbm LPG/ammonia carrier at HMD for delivery in early 2017.
The ship was reported to have been ordered on the back of a long-term charter to commodity trader Trammo Gas.
The initial period is said to be for five years, plus options for up to 10 further years.
