Dowie has just nine games to keep the club in the Premier League and face a must-win trip to bottom side Portsmouth on Saturday.
Hull are currently 19th in the table, three points from safety.
Hull chairman Adam Pearson said yesterday: “We feel that we’ve got a quarter of the season to go with some winnable games within that.
“It’s not a fixture list that’s packed full of ‘top four’ games, it’s a fixture list with games where we would expect to get some points.
“We feel that we’re best served by making the change now. That will bring a fresh face in, some new impetus and some new focus to get those 14 or 15 points that we’re going to need.”