Brokers report the Swiss company has added another couple of 4,900-dwt asphalt and bitumen tankers at Avic Dinheng.
They will be delivered in April and June 2016.
The first two in the series are due from the yard in January and March 2016.
Zurich-based Suisse-Outremer has followed up a double tanker order in China in January with two more vessels.
Brokers report the Swiss company has added another couple of 4,900-dwt asphalt and bitumen tankers at Avic Dinheng.
They will be delivered in April and June 2016.
The first two in the series are due from the yard in January and March 2016.