The deal prices the vessels at $204.5m each for delivery by August, 2017.
DSME said only that the customer was from Europe.
TradeWinds has reported this month that tycoon John Fredriksen was in talks with DSME over two new LNG vessels.
He was said to be looking at ships fitted with M-type, electronically controlled gas-injection (ME-GI) propulsion systems.
Fredriksen last week triggered a mandatory offer for Oslo-listed Flex LNG, which has two LNG carriers being built at Samsung.
He
