PARIS (AP): Sisters Serena and Venus Williams were placed on opposite sides of the French Open field yesterday, while the men's semi-finals could pit four-time defending champion Rafael Nadal against Andy Murray and Roger Federer against Novak Djokovic. Play begins tomorrow.

The possible women's quarter-finals are top-ranked Dinara Safina vs defending champion Ana Ivanovic, Venus Williams vs No. 6 Vera Zvonareva, Serena Williams vs No. 7 Svetlana Kuznetsova and No. 4 Elena Dementieva vs No. 5 Jelena Jankovic.

Safina starts against Anne Keothavong of Britain.

third-seeded

The second-seeded Serena - one of two past women's champions in the draw - will meet Klara Zakopalova of the Czech Republic in the first round. The third-seeded Venus faces Bethanie Mattek-Sands of the United States in her opener.

The Williams sisters could only meet in the championship match. Serena beat Venus in the 2002 French Open final.

Trying to become the first man to win five consecutive French Opens, the top-seeded Nadal will begin against a qualifier. He could meet former No. 1 Lleyton Hewitt in the third round and 14th-seeded David Ferrer in the fourth.

Federer's bid to tie Pete Sampras' record of 14 career major singles title will start against Alberto Martin of Spain. The third-ranked Murray's first opponent is Juan Ignacio Chela of Argentina, whose four career tour titles all came on clay and who once was ranked 15th.

The potential men's quarter-finals are Nadal vs No. 8 Fernando Verdasco, Murray vs No. 7 Gilles Simon, Federer vs No. 6 Andy Roddick and Djokovic vs No. 5 Juan Martin Del Potro.

first Grand Slam

Maria Sharapova will play Anastasiya Yakimova of Belarus in her first Grand Slam match since Wimbledon last year. Sharapova returned to the tour this week after missing nearly 10 months with a shoulder injury and is not seeded.

David Nalbandian, Carlos Moya and Mario Ancic are among the men who withdrew.

The International Tennis Federa-tion had said Dmitry Tursunov would pull out because of a heel injury, but Tursunov was in yesterday's draw, seeded 21st.