Justine Henin will announce her retirement from professional tennis later today, according to reports in her homeland.

Belgian newspaper Het Nieuwsbald reports that the world No 1 will bring her career to an end at the age of 25.

Henin on Friday withdrew from this week's Internazionali BNL d'Italia complaining of fatigue. That decision came a day after the Belgian was upset by Dinara Safina in third round of the Qatar Telecom German Open.

Henin, who has won seven grand slam titles, 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 US 5 million in a single year.

In 20 matches this season, she has already equalled last year's loss total and has won two of her six events played.

The next grand slam is the French Open, which she has won for the last three years.