The number of passengers transported by low-cost air carriers in South Korea soared 21.1 percent for the first nine months of this year from a year earlier, the transport ministry said Thursday. Low cost airlines carried a total of 11.68 million passengers in the January-September period, according to the data by the Ministry of Land, Infrastructure and Transport. Domestic passengers accounted for 8.02 million of the total, up 13.4 percent from the previous year, while the number of international flight passengers grew 42 percent on-year to 3.66 million over the cited period, the ministry said. The budget airlines\' combined domestic market share came in at 48 percent, while their international market share stood at 9.5 percent. Most of the low-cost airlines\' international routes expanded their market shares during the cited period, except for the Incheon-Hong Kong route, the ministry added. The ministry only counted international routes with more than 130,000 passengers.