Mediterranean Shipping Co (MSC)'s contract for six 22,000-teu containerships with Samsung Heavy Industries (SHI) is set to cost about $26m per vessel less than first announced — a move that hints at its choice of propulsion systems.

The initial contract value of KRW 1.118trn ($991m) has been downgraded to KRW 940.7bn, according to a regulatory filing by the Seoul-listed shipbuilder. That represents a drop from $165m per vessel down to $139m each.

The downgrade appears to confirm what TradeWinds reported in August: that the Geneva liner operator has opted for exhaust gas scrubbers over LNG propulsion systems to meet the sulphur emissions cap due to come into force on 1 January 2020.

LNG fuelling systems are estimated to add an additional $20m to the price of each newbuilding, in contrast, scrubbers cost an extra $5m.

SHI is unwilling to comment on the choice of propulsion systems. But, in a regulatory filing last week, it suggests that the recalculation was linked to propulsion options.

In an initial statement on 25 September, the shipbuilder said that six ships would be delivered by the end of December 2019, with options linked.

MSC has contracts for five additional vessels of the same size with DSME, with options.

The combined 11-ship order is the first by MSC for vessels of this size since early 2015.

Alphaliner lists the ships as adding to a fleet that consists of 20 vessels of the 19,000 teu-class that were all contracted in South Korea between July 2013 and early 2015, and all delivered by the third quarter of 2017. Most are financed under leasing or bareboat schemes.

All eyes remain on rival CMA CGM, which has orders for nine 22,000-teu vessels at China’s Hudong-Zhonghua Shipbuilding and Shanghai Waigaoqiao Shipbuilding.

The French operator has been considering LNG-based technology to comply with the emissions cap.

Together, the 20 new ships will add to the 105 vessels of this size that will be in service by 2019, according to Alphaliner.