World number three Roger Federer has split with coach Stefan Edberg after working together for two years.
The 34 year old reached the Wimbledon and US Open finals this year but lost both to Novak Djokovic.
In a statement, the Swiss 17-time Grand Slam winner said it was a "dream come true" to work with the Swede, who he described as "my childhood idol".
Severin Luthi will continue to be Federer's main coach but will be joined by Croat Ivan Ljubicic.
Ljubicic, 36, reached a career high of third in the world rankings and won 10 ATP titles.