South Korea's Korea Gas Corp. (036460.SE) will sign long-term contracts in September to buy a total of 5.64 million metric tons of liquefied natural gas a year from Royal Dutch Shell PLC (RDSA) and Total SA (TOT), the Ministry of Knowledge Economy said Wednesday.

The volume is equivalent to about 17% of
South Korea 's gas consumption last year, the commerce ministry said in a statement.

Kogas will import 3.64 million tons of LNG a year for 20 years from Shell's Prelude gas field in
Australia , with imports set to begin between 2015 and 2018, the ministry said.

The contract allows Kogas to buy 1 million tons a year of LNG from locations such as
Nigeria and Russia from 2013 until Prelude starts production, it said.

Kogas will buy 2 million tons a year from Total between 2014 and 2031 from fields in locations including
Australia , Nigeria , Norway and Egypt , it said.

Long-term supply contracts for LNG from
Indonesia , Malaysia and Brunei totaling 4.7 million tons a year are due to expire between 2013 and 2015, it said.