The Sofia field should be (not all officially confirmed)
#11 Caroline Wozniacki (Seoul)
#13 Nadia Petrova ('s-Hertogenbosch)
#15 Maria Kirilenko (WC)
#16 Roberta Vinci (Dallas)
#19 Kaia Kanepi (Estoril)
#25 Hsieh Su-Wei (Kuala Lumpur, Guangzhou)
#29 Zheng Jie (Auckland)
#44 Tsvetana Pironkova (WC)
#24 Venus Williams (Luxembourg) is qualified but will be playing exhibition tennis in Africa instead and receives a 0 pointer.
Kanepi is doubtful because of a heel injury. If she won't play, the next in line is #32 Daniela Hantuchova (Pattaya City).
The format is the same as in Istanbul: two groups (Serdika and Sredetz) with four players each, the two highest ranked (Caro and Petrova) in different groups. All players play three matches against the other players in her group. The best two in each group advance to the SF, number one from Serdika facing number two from Sredets and vice versa.
If a player wins all her five matches, she'll earn 375 ranking points.
The tournament is played over six days from October 30 to November 4.