RasGas said it now had 13 ships in its fleet and six were built at DSME. Under the terms of the time charter agreement, RasGas will charter the vessel for a period of 20 years to deliver LNG to its customers worldwide.
The Al Jassasiya is owned by a joint venture of Maran Gas Maritime and Qatar Gas Transport Company (Nakilat).
It will have LNG cargo capacity of 145,700 cubic metres.
DSME hosted a function in South Korea where the vessel was formally named by the wife of Tom Cordano, former RasGas board member.
Nakilat last year raised $7.7 billion in loans as part of a programme. Nakilat raised the money from a syndicate of 24 commercial banks, private capital markets, and export credit agencies.
The shipping company plans to build a further 11 LNG carriers in addition to the 13 still on order from South Korean shipyards owned by Samsung, Hyundai and Daewoo.
Nakilat has also entered into management contracts for its LNG vessels with Shell Transport & Trading (Stasco), the oil and petroleum products shipping arm of Royal Dutch Shell.