South Korea's Ministry of Land, Infrastructure and Transport has approved this year's summer schedule for local and foreign airlines.
From 31 March, the ministry has allowed 77 airlines to operate 3,063 flights a week on 332 routes.
This year, 18 routes and 225 weekly frequencies were added, an increase of 5.7% and 7.9% respectively compared with last year, the ministry says.
Airlines based in China have the largest share of weekly frequencies at 915, followed by Japan with 663 frequencies. Airlines from the USA, Hong Kong and the Philippines each have 474, 207 and 186 frequencies respectively.
Expanded capacity entitlements granted by Asian countries allowed low-cost carriers to expand their operations to 258 weekly frequencies. Domestic airlines Jin Air, Air Busan and Eastar Jet have all launched international services from Seoul, Busan, Jeju and Cheongju to destinations in China, Japan, Macau and Taiwan.
In terms of domestic frequencies, the LCCs have since overtaken Asiana Airlines and Korean Air. They now operate 691 frequencies, up by 12.2% compared with a 0.2% increase for the two full-service carriers.
While Jeju airport had a 9% growth in frequencies, the eight South Korean domestic airports, meanwhile, suffered a loss of 19 weekly frequencies, reducing it to 425, the ministry adds.