Maguire, 30, has been out of favour at United under Ten Hag, making just 16 appearances in the Premier League last season, including just eight starts.
“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,” Maguire said in a Twitter post on Sunday.
“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.”
Maguire had been a regular starter at United since his £80 million ($104 million) move from Leicester in 2019 and was named captain by former boss Solskjaer in January 2020.
He was renamed captain when Ten Hag replaced Solskjaer at Old Trafford last summer, but he has seen his game time significantly reduced with Raphael Varane and Lisandro Martinez preferred at centre-back.
It has been widely reported that United are willing to listen to offers for Maguire this summer and anticipate interest from West Ham, who made an enquiry about his availability during the January transfer window.