The 60-year-old coach replaced Nader Dastneshan in the Abadan-based club.
Karimi is one of Iranian high-profile coaches as he has won Asian Club Championship with Pas in 1993.
He started his coaching career in 1989 with 2nd Division Pas and won promotion to Azadaegan League one year later.
Karimi has already coached at Iranian clubs Bahman, Mes Kerman, Sepahan, Esteghlal, Rah Ahan, Esteghlal Ahvaz, Tractor Sazi, Shahin Bushehr, Malavan, Saba Battery, Zob Ahan and Damash Gilan.
Sanat Naft, who won promotion to Iran Professional League in this season, remains 11th with 16 points from 15 games.