- Roger Federer and Rafael Nadal in same group at ATP Tour Finals
- Federer bidding for record sixth win in end of season championships
- World No.1 Novak Djokovic heads Group A which also includes Andy Murray
- Tournament starts Sunday at 02 Arena
Defending champion Roger Federer has been drawn with longtime rival Rafael Nadal in the group stages of the ATP World Tour Finals in London next week.
Federer beat Nadal in the final of the end-of-season championships last year and will go into the tournament at the 02 Arena off the back of tournament wins in Basel and Paris.
Group B is completed by Frenchman Jo-Wilfried Tsonga and American Mardy Fish.
World No.1 Novak Djokovic heads Group A where he is joined by home hope Andy Murray, Tomas Berdych of the Czech Republic and Spain's David Ferrer.
Djokovic pulled out of last week's Paris Masters at the quarterfinal stage to protect a nagging shoulder injury, but is hopeful of being able to compete in London.
The Serbian has dominated this season with three grand slam titles, the first in Australia where he beat Murray in the final.
The 30-year-old Federer will be bidding for a record sixth finals title to break out of a tie with Ivan Lendl and Pete Sampras.
His only grand slam final appearance this season came at the French Open where he lost to Nadal on the Paris clay.
Murray, who has overtaken Federer for third spot in the world rankings, won three straight tournaments before a quarterfinal loss to Berdych in Paris.
The tournament begins on Sunday with Federer taking on Tsonga in a repeat of the Paris Masters final he won in straight sets.
World No.2 Nadal then faces Fish in the evening session.
Murray starts against Ferrer Monday afternoon with Djokovic in action for the first time in the evening session against Berdych.
The top two from each group progress to the knockout semifinal stage with the final held on Sunday November 27.
The world's top eight doubles teams are also competing in London, which is staging the tournament for the third time.
Group A: Novak Djokovic (SRB), Andy Murray (GBR), David Ferrer (ESP), Tomas Berdych (CZE)
Group B: Rafael Nadal (ESP), Roger Federer (SUI), Jo-Wilfried Tsonga (FRA), Mardy Fish (USA)