Malaysia’s MISC Berhad kicked off its LNG carrier partnership with ExxonMobil’s SeaRiver Maritime on Tuesday with the delivery of the 174,000-cbm sister ships Seri Damai and Seri Daya from Samsung Heavy Industries.

The pair, which are touted as being the most energy efficient vessels of their type, were ordered against 15-year time charters to the US energy giant’s wholly-owned shipping subsidiary.