The airport suffered a setback recently when Hong Kong Express Airways terminated its scheduled services to the city while Tiger Airways has significantly slashed its flights numbers. Hong Kong Express used to operate two flights a week between Hong Kong and Chiang Mai, using Boeing 737 jetliners. Singapore-based budget carrier Tiger Airways has cut its frequencies on the Singapore-Chiang Mai route, also using Boeing 737s, to two from six flights a week. The two carriers shifted the capacity to other busier routes as travel demand to the northern city from their originating ports has dropped off after the New Year holiday season, according to industry sources. Chiang Mai has not been able to attract direct overseas passenger traffic as hoped as efforts to especially promote the region's tourism have yet to bear fruit, said Prateep Wichitto, the airport's general manager. The pull-out of Hong Kong Express means that there are only eight international carriers operating scheduled flights through Chiang Mai. There is another foreign carrier that operates through Chiang Mai, Sky Star of South Korea, but on a charter basis, with a total of 40 flights scheduled between Dec 2007 and April 2008. The only newcomer was Korean Air, which began to fly four flights from Incheon to Chiang Mai in October last year. The number of international carriers serving Chiang Mai appeared to be stagnant over the past few years, representing only 10% of all 75 daily flights through the airport. Chiang Mai is now served by six Thailand-based carriers: Thai Airways International, Thai AirAsia, Bangkok Airways, Nok Airlines, Orient Thai Airlines, One-Two-Go Airlines and the commuter carrier SGA Airlines. Chiang Mai is heavily under-utilised, handling about three million passengers a year, mostly domestic passengers, compared to its design capacity of eight million a year. It raised questions about the economic return from the two-billion-baht investment Airports of Thailand Plc (AoT) has spent in the past few years in expanding the airport, very much geared toward handling more international traffic.