World men's tennis number two Novak Djokovic has split with coach Boris Becker three years after adding the German grand slam winner to his team.
Serbian Djokovic, who won six of his 12 major titles after hiring Becker but has suffered a slump in form over the past six months, confirmed their parting of ways on his website.
"After three very successful years, Boris Becker and I have jointly decided to end our cooperation," Djokovic, who lost his number one ranking to Andy Murray last month, said.
"The goals we set when we started working together have been completely fulfilled, and I want to thank him for the cooperation, teamwork, dedication and commitment."
The pair joined forces in December 2013.
After winning the Australian Open for a sixth time and then claiming a first French Open this year Djokovic, 29, was on course to complete calendar year grand slam - a feat last managed in 1969 by Australian great Rod Laver.
But he bowed out in the third round of Wimbledon to Sam Querrey, lost in the first round of the Rio Olympics to Juan Martin del Potro and then went down to Stan Wawrinka in the US Open final.
Without a title since July, Djokovic also saw an 8,000-point ranking lead over Britain's Murray vanish.
Murray dethroned Djokovic after 122 weeks at the summit in November and then beat him to win the season-ending ATP World Tour Finals, snapping the Serbian's four-year domination of the London tournament.
Djokovic did not reveal whether he would replace Becker and there was nothing to suggest long-term mentor Marian Vajda would be leaving his entourage, although the Belgrade native indicated he wanted to make his own choices.
"My professional plans are now directed primarily to maintain a good level of play, and also to make a good schedule and new goals for the next season," Djokovic said.
"In this regard I will make all future decisions."