Mark Allen has submitted his resignation as Ranger Football Director after more than two years with the Scottish Premiership Club.
Rangers say he has decided "for family reasons and to explore other options".
The former head of the Manchester City Academy was responsible for bringing Steven Gerrard to Ibrox as manager.
Gerrard said, "Mark's success is visible to everyone and we wish him all the best for the future."
Allen was responsible at Ibrox for a busy transfer summer in which nine signings and six signings from the first-team squad were eliminated.
It ended with the return of £ 7 million worth of Liverpool's former livestock Ryan Kent on the day of the transfer. Gerrard insisted that it was not just after the 0-2 home defeat against Scottish Premiership owner Celtic that it was a panic purchase funded by qualifying for the Europa League group stage.
"I want to sincerely thank Mark for the incredible support he has shown me and all my staff since I joined the club 16 months ago," Gerrard said on the Rangers website.
According to Ibrox, Allen "has helped Rangers take a much stronger and more challenging position" after "playing a key role in the successful overhaul of the football department."
"During his tenure, Mark has made a very positive contribution to improving the quality of the first-team player and refurbishing and improving the Hummel Training Center, making it suitable for a Rangers-sized club." specified.
Allen said it was "a privilege to work for Rangers, one of the biggest clubs in football, and that 'I loved every minute'.
"Bringing Steven Gerrard into the club is always going to be a special moment in my career and I want to thank him, his excellent staff, the Rangers players and all the staff for their support during my tenure."
CEO Stewart Robertson expressed his disappointment at Allen's decision.
"But we appreciate the impact he has made during his time in Scotland, and he leaves Rangers in a better place than when he arrived," he said.
"Losing a man of his caliber is a stroke, but the practices he has introduced in the club will be of benefit to us in the future."