It was reported earlier this month that Ten Hag was ready to remove Maguire from the role after the England defender’s limited appearances under the Dutchman last season.
The central defender made just eight Premier League starts, leading to ongoing speculation over his future at Old Trafford.
Maguire wrote on Twitter: “After discussions with the manager today he has informed me he is changing captain.
“He outlined his reasons to me and whilst I’m personally extremely disappointed, I will continue to give my all every time I wear the shirt.
“So I wanted to say a massive thank you to the Manchester United fans for all their brilliant support whilst I’ve been wearing the armband.
“Since the day I took on the role, three and half years ago, it’s been a huge privilege to lead Manchester United and one of the proudest moments of my career to date.
“It’s one of the greatest honours in club football. I’ve done everything I possibly could to help United be successful – on and off the field.
“I will always be grateful to Ole Gunnar Solskjaer for first giving me the responsibility and I wish whoever now takes it on every success and they will have my full support. Harry.”
In Maguire’s absence from the side last season, Bruno Fernandes was most frequently appointed captain and the Portugal midfielder is expected to be given the permanent role.
Maguire has made over 170 appearances for United since being signed from Leicester for £80million in 2019.
The England regular has been linked with a move to West Ham in recent days.