BANGKOK Airways is launching a business class service between Bangkok and Phnom Penh, and increasing its flight frequency from two per day to three on March 29, the airline said in a statement Wednesday. The new service includes the introduction of an Airbus 319, which offers both economy and business-class seating. The airline's expansion also includes a package holiday deal for Cambodia that includes flights and accommodation to Koh Samui, Thailand, said spokesman Ekkaphon Nanta O'sot.