Competition for air routes connecting Korea and the Philippines is heating up. Currently only the two flag carriers Korean Air and Asiana Airlines are flying from Incheon and Busan to four cities in the Philippines -- Manila, Clark, Cebu and Kalibo. But by January next year, domestic and foreign budget airlines will open new routes or increase the number of flights. Jeju Air plans to fly Incheon-Manila five times a week from October, and Jin Air is working on an Incheon-Clark route five times a week starting in October or November. Air Busan is also reportedly mulling a service to the islands from Busan, to be launched in December. In the Philippines, meanwhile, Zest Air began operating a Kalibo-Incheon service in December, which flies four times a week, and an Cebu-Incheon route in July, also four times a week. Cebu Pacific is considering increasing the Manila-Incheon route from seven times a week to 14 in January. The reason for the sudden increase is permission from the Ministry of Land, Transport and Maritime Affairs last month for Filipino budget airlines to fly Korea's aerial routes. Korea and the Philippines have not signed an Open Skies Agreement that allows the carriers of both sides to fly unlimited routes unlimited times in each others' aerial domains. Instead, they negotiate once a year to distribute licenses. The Philippines is one of the favorite destinations for Korean tourists and therefore a treasure trove for airliners. A Jin Air staffer said, "For a budget airliner, traditional tourist destinations are more profitable than business destinations. Because the Philippines is just four hours away from Korea, many budget airlines had been working very hard to get the license to fly."