government who were very keen to have the event for the purpose of promoting China and Shanghai and also promoting the sport of tennis in China , '' he said . `` Here it was us wanting to bring the event back to the traditional market of Europe , and in particular London . '' The UK capital has a contract until 2013 , but doubts have been raised about the event 's future on the banks of the River Thames due to complaints about British laws which require players to be taxed on all endorsements during the time they are in the country . The Lawn Tennis Association , which runs Wimbledon and is also an event partner of the ATP finals , is lobbying the government for an exemption . `` If we lose events like this it will have a big impact not just on the economy but also on sponsors and television and in other areas , '' LTA chief executive Roger Draper told the UK Press Association . Can Federer make finals history in London ? Drewett said the ATP is happy for the event to stay in London , which is one of the
-LRB- CNN -RRB- -- Brad Drewett is reluctant to divulge exact numbers , but the ATP World Tour Finals is a big deal for men 's tennis . The season-ending event , worth $ 5 million in prize money this year , is the tour 's marquee event -- an elite eight-man showpiece that attracts top sponsors and acts as a massive advert for the game . `` It 's one the of the ATP 's biggest assets , '' longtime tournament director Brad Drewett told CNN during this week 's round-robin matches . `` For it to be a commercial success is extremely important for us . '' Drewett , a 58-year-old former tennis prodigy , has been running the finals for more than a decade now . It came to London 's glitzy O2 Arena -- best known as a concert venue -- in 2009 after Drewett took it back to Shanghai for three years . Rihanna to Rafa : Tennis gets popstar makeover `` The actual financial structure is a bit different . We have a partnership here with AEG , the owners of the O2 , whereas in Shanghai we had a partnership with the municipal