British number one Andy Murray has been drawn to play Stanislas Wawrinka, Rafael Nadal and David Ferrer in the Ilie Nastase group at the ATP World Tour Finals in London.
World number one Novak Djokovic and seven-time Wimbledon champion Roger Federer, meanwhile, are in the Stan Smith group alongside Tomas Berdych and Kei Nishikori.
In the doubles, Jamie Murray and John Peers have been drawn in the same group as 16-time Grand Slam champions Mike and Bob Bryan.
The finals take place between November 15 and November 22 at the O2 Arena.
Stan Smith group draw:
Novak Djokovic Roger Federer Tomas Berdych Kei Nishikori
Ille Nastase group draw:
Andy Murray Stan Wawrinka Rafael Nadal David Ferrer
Ashe/Smith group draw:
Bob Bryan & Mike Bryan Jamie Murray & John Peers Simone Bolelli & Fabio Fognini Rohan Bopanna & Florin Mergea
McEnroe/Fleming group draw:
Jean Julien-Rojer & Horia Tecau Ivan Dodig & Marcelo Melo Nicolas Mahut & Pierre-Hugues Herbert Marcin Matkowski & Nenad Zimonjic