Sports director Max Eberl said it was a strategic decision and had nothing to do with the team's form. They have dropped to fifth in the league, having won one of their last seven matches, and are two points off the Champions League spots.
"I informed Dieter already on Monday," Eberl told reporters. "It is a decision I took as sports director which has a strategic nature. It is a decision for the good of the club. It has nothing to do with the current sporting situation."
The 54-year-old Hecking has been in charge since 2016 and his contract at Gladbach ran to 2020.
"The team is playing extremely well despite the recent results which are not good. I would be happy to leave having secured a Champions League spot," Hecking said.
"Such decisions are never easy. That is why it was a big disappointment yesterday and it has lasted until today. But when the sports director has a new strategy then you have to accept it."
(Reporting by Karolos Grohmann; Editing by Ken Ferris)
