British world number three Andy Murray has split from coach Amelie Mauresmo after two years.
Murray, 28, said he had "learnt a lot" from Mauresmo but they had "mutually agreed" to end their partnership.
"Dedicating enough time along with the travel has been a challenge," twice Grand Slam champion Mauresmo added.
Since he began working with her in June 2014, Murray has won seven titles - including his first two on clay - but has failed to add to his two majors.
In a joint statement, Murray added: "She's been a calming influence in the team and we will all miss having her around.
"I'll take some time to consider the next steps and how we progress from here, but I'd like to thank her for everything she has done. She's been an invaluable member of the team."
Frenchwoman Mauresmo, 36, who gave birth to her first child in August 2015, added: "Working with Andy over the last two years has been a fantastic experience for me.
"I've thoroughly enjoyed being part of the great team of people he has around him. I wish him and the team well and I hope he goes on to win many more titles."
Murray - who lost his number two ranking to Roger Federer after his defeat by Novak Djokovic in the Madrid Open final on Sunday - was previously coached by former world number one Ivan Lendl, under whom he won the 2012 US Open and 2013 Wimbledon.
The Scot was the first leading male player to employ a female coach, saying at the time of the appointment: "I've always had a strong female influence in my career and that's something I needed right now."
BBC Radio 5 live tennis correspondent Russell Fuller:
"Murray has always maintained he needs to spend 25 weeks a year with his head coach, and - even if a final decision was only taken last week - it has become apparent over the last few months that as a new mum, Mauresmo would be unable to find that time. She trained with Murray in Dubai in December, but since January's Australian Open, has only been on coaching duty in Miami.
"Murray has been unable to add to his Grand Slam tally in their two years together, but has become phenomenally consistent and something of a clay-court natural. He will miss the calmness she brought to the team, and may struggle to find someone of similar experience whom he feels as comfortable confiding in.
"Murray will, for now, work exclusively with Jamie Delgado, as he begins to sound out potential successors to Mauresmo. You would expect him to seek someone with a glittering playing or coaching CV, but that is a limited pool and he is not an easy man to second guess. Murray is always happy to buck the trend, but won't do so just for the sake of it."