Ahmed Riyadh al-Karbouli worked for Baghdad TV, a satellite channel owned by the Sunni Iraqi Islamic Party.
The media group said al-Karbouli had received numerous death threats over the past four months warning him to leave Baghdad TV.
In other violence on September 18, a suicide bomber killed at least 21 people at a market in the northern city of Tal Afar. Another 17 people were wounded.
U.S. officials recently warned that violence might increase ahead of Ramadan, which starts in 10 days' time.