The former Premier League side is 12th in the League Championship, eight points adrift of the playoff places, and the club's owners have chosen to act in a bid to challenge for the top places in the table next season.
"The decision has been taken with a view to preparing for the 2013-14 season, and Neil Redfearn will be asked to take control... until a permanent appointment is made," the club's statement read. "This may well be after the end of the season dependent on the availability of suitable candidates changing all the time then we will adopt a flexible approach, so as to ensure that we make the right appointment.
"A short-list has already been prepared as Neil was always going to leave at the end of the season in the event that we did not get promotion."
Chief executive Shaun Harvey emphasized the need to look to the future, and he maintained that the need for promotion next season was the club's main consideration even though the club is not mathematically eliminated yet this season.
"We would like to thank Neil for his efforts during his time as our manager and share his disappointment that we could not achieve promotion this season," Harvey stated. "We now need to look to the future and the search for his replacement is underway, for which there is no fixed timescale as securing the services of the right person is the primary objective, so as to give us the best chance of promotion next season.
"We would also like to thank Mick Jones and Ronnie Jepsom, who will leave the club with Neil, for all their hard work since coming to the club."