British number one Andy Murray has parted company with coach Brad Gilbert after 16 months working together.
Gilbert and Murray had an often tempestuous relationship
Murray teamed up with Gilbert in July 2006 and rose from 36 in the world rankings to a high of eight.
In a groundbreaking deal, the Lawn Tennis Association paid Gilbert's salary, reportedly about £750,000.
The American signed a three-year contract as a performance coach and, alongside looking after Murray, had a wider role within the LTA.
Murray said: "Despite being injured for almost four months this year, I am pleased with my 2007 results and am very grateful for the help that the LTA have given me by providing Brad Gilbert as a coach.
We are currently reviewing the situation in relation to Brad and will look to make a decision in the near future
LTA chief executive
"But the time has come to move on to the next stage of my career.
"I am ranked 11 in the world and can now afford to pay my own way and so will now hire a team of experts each to fulfil a specified role in the development of my tennis and fitness."
Gilbert's role with the LTA included taking training camps both in the UK and abroad and "helping to raise the playing and coaching standards in the UK".
Whether he will continue with this lower-profile work having split with Murray is uncertain.
Roger Draper, chief executive of the LTA, said: "Andy has had another great year and despite a serious injury has demonstrated that he is a truly world class player.
"Whilst working with Brad he has broken into the top 10, won two ATP titles and reached three finals.
"Andy's success is vital for British tennis and he has become an inspirational figure for followers of the sport.
"It is essential that he has a team around him that will allow him to fulfil his potential. We are currently reviewing the situation in relation to Brad and will look to make a decision in the near future."
The fact that the governing body of tennis in the UK was paying a very large salary to the coach of one of its players was controversial - as was the size of the salary.
Former Wimbledon champion Pat Cash described it as "one of the most outrageously over-hyped, over-exaggerated fees in history - probably three times more than what any other coach is paid. The LTA will have to look at themselves and think: 'We blew this one'.
"It's thrown a spanner in the works for them."
But Gilbert came with a CV that included working with former world number ones Andre Agassi and Andy Roddick.
By the end of 2006 he had guided Murray to 17 in the world and the Scot reached a career high of eight in June.
And despite missing three months of this year through injury, Murray was still just one victory from securing a place in the Masters Cup - currently under way in Shanghai - for the world's best eight players.
As for Murray's possible next coach, BBC Radio 5 Live tennis correspondent Jonathan Overend said: "The guy who, for me, is top of the list of favourites to be his new coach is a Canadian by the name of Louis Cayer, who has been working with Andy's brother, Jamie.
"He is specifically a doubles coach but he is very well regarded. He is very technical, very analytical, works on patterns on the tennis court, that sort of thinking that Andy Murray relates a lot to.
"He is a technical, astute kind of thinker about the sport."