World number six Angelique Kerber of Germany is among the latest players to qualify for the $4.9 million end-of-season grand finale in Istanbul later this month, organisers said Thursday.
The 24-year-old will line up alongside the season's top eight players at the WTA Championships from October 23-28, which will also include Petra Kvitova of the Czech Republic and Italy's Sara Errani, the organisers added.
The three join Victoria Azarenka, Russia's Maria Sharapova, reigning Wimbledon and US Open champion Serena Williams, and Agnieszka Radwanska of Poland in having already qualified, with just one remaining place up for grabs.
Kerber has risen from 32nd place in the rankings at the end of 2011 to sixth currently. This year she won her first WTA singles title in Paris in February and followed it with another in Denmark in April.
The left-hander also reached the semi-final of Wimbledon for the first time.
"This has been the best year of my career," Kerber said. "To have the opportunity to play at the Championships will be an amazing way to end 2012."
Stacey Allaster, WTA Chairman and CEO, congratulated the three, adding: "Angelique and Sara have both achieved their career-best seasons, while Petra has solidified her position in the world's top 5 and is a proven contender at any tournament."
Four players are in contention for the final spot -- Li Na, Samantha Stosur, Marion Bartoli and Caroline Wozniacki.