China's Guangzhou Shipyard International has won an additional order for 39,000-dwt PC.
Rederi AB Gotland of Sweden is looking to strengthen its focus on medium-range (MR) tankers.
The company says it has declared an option for a second 39,000-dwt products tanker at the yard.
The owner went to the Chinese yard in June for one firm ship plus one option, confirms Gotland director Ann Mari Aastrom.
The first vessel is due for delivery in 2012, with the second to follow either in late 2012 or early 2013.