Justine Henin has announced her retirement from professional tennis at the age of 25.

The world number one has brought her career to an end with immediate effect.

She said: "It's the end of a wonderful adventure but it's something I have been thinking about for a long time."

Henin, who has seven grand slam titles to her name, had not played a WTA Tour event since the first week of April, when she endured a 6-2 6-0 loss to Serena Williams in the Miami quarter-finals. She cited a right knee injury as the reason for the recent lay-off.

Henin won ten of the 14 events she entered last season, posting a 63-4 record and becoming first player in tour history to win over £2.5 million in a single year.

Henin equalled last year's loss total in her first 20 matches this season and won two of her six events played.

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