Cheung Chi-kong will retire at the end of August as head of NOW TV News after leading the news department for the past 15 years.
Cheung will be succeeded by another veteran, Bill Chan who has retired from rival TVB News last year.
Chan will begin as the new head of NOW TV News on June 23, with Cheung to stay on as a senior consultant until the end of August.
PCCW Media Group managing director Janice Lee Hoi-yee thanked Cheung for his contributions over the past 15 years and said he is a vital founding member of the channel.
Bill Chan is widely known for his close China connection in his three decades of journalistic career, so close that some journalists have expressed their worries over his recruitment is a "political task" imposed by Beijing.
Now TV News was top rated as the most credible news source by a Chinese University's poll over Hong Kong news media last year.
Now TV News also broadcasts Cantonese and English news to its affiliate VIU TV.