Okay Airways, China's first private airline, has signed a preliminary agreement to sell a 25 % stake to Korean Air Co for around US$8.6 million, The Standard of Hong Kong reported. The group, which started flights from Tianjin's Binhai International Airport earlier this year, first entered into talks with Korean Air in June on a possible joint venture. The Korean airline said the pricing, acquisition terms and the timing of the takeover would be finalized after due diligence.