The 18-year-old Ko, who has been below par in recent times, finished in a tie for third, one shot behind Koreans Chella Choi and Ha Na Jang. The 24-year-old Choi won her first LPGA title in a playoff.
Ko, the world number two, made a strong birdie-filled start on the front nine in the final round and led by two shots but couldn't sustain the charge and finished in a tie alongside China's Shanshan Feng.