SEOUL, Jan 16 (Reuters) Tech giant Samsung Electronics Co Ltd will announce the results of its investigation on what caused some Galaxy Note 7 smartphones to catch on fire on January 23, South Korea's Yonhap News Agency reported on Monday citing unnamed sources. Samsung in October ended sales of the near-$900 Note 7 smartphones in what is one of the biggest product safety failures in tech history. The firm has been looking into what caused the phones to catch fire along with third-party researchers. Samsung could not be immediately reached for comment. REUTERS AKC 0600