Roger Federer of Switzerland and Spain's Rafael Nadal have been named the top two men's seeds at the Wimbledon tennis Championships, which get under way Monday in London.

Federer will be trying for his fifth straight title on the grass courts of the All England Club, after he beat Nadal in last year's final. But Nadal, who has dominated Federer on clay, is expected to give Federer a bigger challenge this year. The Spaniard is trying to become the first player since Sweden's Bjorn Borg in 1980 to follow up a French Open victory with a win at Wimbledon.

American Andy Roddick, who won last week's grass court warm-up tournament at Queen's is seeded third, followed by Serbia's Novak Djokovic of Serbia and Chile's Fernando Gonzalez. Djokovic's good record on grass earned him the fourth seeding, one place above his world ranking.

In the women's draw, French Open champion Justine Henin of Belgium has the top seed followed by Russian star Maria Sharapova. Jelena Jankovic of Serbia is third ahead of fourth-seeded defending champion Amelie Mauresmo of France. Svetlana Kuznetsova of Russia rounds out the women's top five.

The men's and women's seedings are primarily determined by the player's tour rankings, but are adjusted for their record on grass courts.

Former Wimbledon champion Serena Williams is the highest seeded American in the women's draw at number seven.

Some information for this report was provided by AFP and AP .