World number six Tomas Berdych of the Czech Republic and number nine Janko Tipsarevic of Serbia head a strong field for the next edition of the ATP Chennai Open, organisers said on Thursday.
The 15th-ranked Marin Cilic of Croatia and number 17 Stanislas Wawrinka of Switzerland are the other top-20 players taking part in the $450,000 season opener in the southern Indian city of Chennai from December 31.
Berdych, 27, ended the previous season by winning his opening singles and doubles tie with Radek Stepanek in his country's memorable 3-2 win over Spain in the Davis Cup final in Prague last week.
Tipsarevic opened 2012 by bagging the doubles title at the Chennai Open with Indian ace Leander Paes, but lost in the singles final to big-serving Canadian Milos Raonic.
Raonic will not return to defend his title in South Asia's biggest tennis tournament, which serves as a warm-up for the Australian Open in Melbourne in mid-January.
Tipsarevic and Wawrinka are set to make their fifth appearance in the tournament, while Cilic will look to add a third Chennai Open title to those he won in 2009 and 2010.