ATP Tour Finals to remain in London until at least 2020
The end-of-season ATP finals will remain in London until at least 2020, after a two-year extension was agreed.
The event - live on BBC TV, radio and online - features the ATP's top-ranked eight singles players and doubles teams competing over eight days.
The O2 has been the home of the tournament since 2009, with more than 250,000 fans attending each year.
Andy Murray will defend his singles title in this year's tournament, which will be held from 12 to 19 November.
In November last year, Murray ensured he ended 2016 as world number one when he won the title for the first time with a 6-3 6-4 victory over five-time champion Novak Djokovic.