The 29-year-old has featured in 53 U's games since joining in 2015, 18 of which have come this season.
"He came and requested the opportunity to leave for personal reasons," said director of football Tony Humes.
"We have been working with him over the past few weeks to resolve the situation in the best way possible."
Colchester United midfielder Owen Garvan has had his contract with the League Two club cancelled by mutual consent for personal reasons.