Tiger Woods has decided to part company with longtime caddie Steve Williams, a move that took the New Zealander by surprise after he helped the former world No. 1 to win 13 majors.

Williams, who had been a regular caddie for Woods since 1999, has recently been carrying the bag for Australia's Adam Scott while Woods has been injured.

"I want to express my deepest gratitude to Stevie for all his help, but I think it's time for a change," Woods said in a statement on his website (www.tigerwoods.com).

"Stevie is an outstanding caddie and a friend and has been instrumental in many of my accomplishments. I wish him great success in the future."

Williams, on his own website (www.kiwicaddy.co.nz), said: "Needless to say this came as a shock.

"Given the circumstances of the past 18 months working through Tiger's scandal, a new coach and with it a major swing change and Tiger battling through injuries, I am very disappointed to end our very successful partnership at this time," Williams added.

Woods did not name a replacement for Williams, who previously worked for Greg Norman and Raymond Floyd, or say when he would return to competition from leg injuries.

Following last year's US Open, Woods told reporters there was no tension between him and Williams, despite having made comments that were widely interpreted as critical. After the final round at Pebble Beach, Woods said he had made three mental mistakes and gone against his instincts.

Woods hurt his knee and Achilles tendon during the US Masters in April and has not played since he pulled out of The Players Championship in May after playing just nine holes.

He has not won a major since the 2008 US Open nor any tournament worldwide since 2009 and his world ranking has fallen to No. 20.

Woods has also been trying to rebuild his golf swing and his private life following the breakup of his marriage after he confessed to a string of affairs.