Federer, Henin get top billing at Wimbledon

The seeding for next week's Wimbledon championships were announced on Wednesday with the All England Club again using players' grasscourt credentials to come up with their top 32.

Four-times defending champion Roger Federer tops the men's seeding with French Open champion Rafael Nadal of Spain second and American Andy Roddick, twice a runner-up at Wimbledon, third.

• Wimbledon seedings

Unlike the other Grand Slams where the top 32 seeds in the men's and women's singles are decided purely on world rankings, Wimbledon takes into account results on grass in the past two years, particularly in the men's draw.

Chief beneficiary of the unique seeding system is Czech Tomas Berdych, who is seeded seven in the men's event compared to a world ranking of 11.

The leading women's seeds go according to ranking with world number one Justine Henin, fresh from clinching a hat-trick of French Open titles, at the top. The world's best on clay, she is looking for her first Wimbledon triumph.

Last year's women's winner Amelie Mauresmo is fourth seed, behind Maria Sharapova and in-form Serb Jelena Jankovic.

Australian Open champion Serena Williams, twice a Wimbledon winner in 2002 and 2003, is the seventh seed, in accordance with her ranking. Her sister Venus, who won the third of her titles in 2005, has suffered injury woes this year and is seeded 24th.

Russian world men's number four Nikolay Davydenko drops to sixth in the seeding, meaning Serbia's Novak Djokovic and hard-hitting Chilean Fernando Gonzalez are bumped up to fourth and fifth respectively.

World number seven Tommy Robredo finds himself down at 11th because of his poor record on grass.

Marcos Baghdatis, a semi-finalist last year, is seeded 10th, six places higher than his world ranking. Likewise, veteran Swede Jonas Bjorkman finds himself seeded 20th, compared to a world ranking of 31, after his surprise last four run in 2006.

Britain's Andy Murray has been seeded at number eight but his participation in the tournament hangs in the balance as he works on his fitness following a wrist injury.