Novak Djokovic has clinched the year-end No. 1 ranking.
Djokovic lost the top spot to Roger Federer in July but will return to No. 1 next week.
The ATP says Federer will drop points from his 2011 title wins at the Swiss Indoors and Paris Masters. He lost in the Swiss Indoors final Sunday to Juan Martin del Potro, and then pulled out of next week's Paris tournament.
The ATP says Federer will not be able to earn enough points to finish the year ahead of Djokovic.
The Serb will become the first player to finish No. 1 in consecutive years since Federer did it four straight times from 2004-07.
Djokovic will be officially crowned No. 1 during a presentation at the World Tour Finals in London next week.