Rangers announced on Monday night that Kenny McDowall has tendered his resignation as caretaker manager of the club.
The former St Mirren striker, who was on the coaching staff at Celtic before moving to Ibrox in 2007, stepped up from assistant boss when Ally McCoist left last month.
A club statement read: "Kenny McDowall has tendered his resignation as caretaker manager of Rangers Football Club, citing personal reasons for stepping down.
"Kenny, who has been a fantastic servant of the club, will serve his 12-month notice period, during which time he will remain 100% committed to his normal duties.
"The club respects Kenny’s decision and he will continue to have the full support of everybody at Rangers."
Rangers play Cowdenbeath in a Championship match at Central Park on Saturday then face Celtic in the semi-finals of the League Cup the following weekend.