Air Busan Co. has added an A321-200 jet to strengthen its services, bringing the number of its fleet to 21, the company said Friday.

The 220-seat plane will be mainly operated on the domestic routes to Jeju Island, with two planes scheduled to be added within this year, Air Busan said in a statement. 

On domestic routes, nearly 60 percent of customers opt to use low-cost carriers in the January-May period due to improved safety control and competitive prices.

In 2016, the country's six budget carriers -- Jeju Air, Jin Air, Air Busan, Air Seoul Inc., Eastar Jet and T'way Air Co. -- transported 56.8 percent of the passengers on domestic routes and 19.6 percent of passengers traveling abroad. The figures mark a gain from 54.6 percent and 14.6 percent, respectively, from a year earlier, the transport ministry said.

Last year, passengers on domestic routes jumped 11 percent on-year to 30.91 million and passengers on international routes climbed 19 percent to 73 million, it said. (Yonhap)