LONDON (Reuters) - Wimbledon champion Andy Murray has split with coach Ivan Lendl after two years, the British world No. 6 said on Wednesday.

Murray, who won his first grand slam under Lendl's guidance at the 2012 US Open and became Britain's first men's singles champion at Wimbledon for 77 years, has had a disappointing start to the year after returning from back surgery.

"I'm eternally grateful to Ivan for all his hard work over the past two years, the most successful of my career so far," Murray said in a statement on his Twitter page.

"As a team, we've learned a lot and it will definitely be of benefit in the future. I'll take some time with the team to consider the next steps and how we progress from here."

Murray, who also won an Olympic gold under former world No.1 Lendl, is currently in Miami trying to defend his title at the Masters Series event.