NEW YORK — World No. 3 Maria Sharapova will compete in her eighth Women's Tennis Association (WTA) Finals next month in Singapore after officially qualifying this week, the women's tennis governing body said Thursday. The 28-year-old Russian, who missed the US Open because of injury, won the event on her debut in 2004 and has since reached the final twice in 2007 and 2012. Grand-Slam chasing Serena Williams, winner of the last three Women's Tennis Association end-of-year tournaments, and Romania's Simona Halep have also booked their tickets for the Oct. 23-Nov. 1 event. Five more places are still available. — Reuters