London Olympics 2012: Lord Coe in IOC plea over tickets
Lord Coe has urged the International Olympic Committee (IOC) to return any unwanted London 2012 tickets after "phenomenal and unprecedented" demand.
He said the level of ticket sales was an "extraordinary vote of confidence" in Olympic sport around the world.
The Games chairman was reporting on the progress of London 2012 to the 123rd IOC Session in Durban, South Africa.
National Olympic committees have about 12% of tickets to sell, and 5% more go to the IOC and sporting federations.
Lord Coe told the IOC: "Both domestically and internationally the demand for tickets has been phenomenal, I would actually say it has been unprecedented. 1.9 million people applied for 22 million tickets, we have 6.6 million to distribute.
"We have sold out in 23 out of 26 sports, that's an extraordinary vote of confidence in Olympic sport, not just in Britain but around the globe."
Lord Coe said with such clamour for tickets some people were bound to be left disappointed.
"We promised full venues and affordable prices. There has been disappointment, with that level of demand it is inevitable," he said.
"My message is: 'If you have tickets you have not yet sold then please send them back to us'. I know people who would like them."
Lord Coe admitted there would be challenges surrounding transport during next year's Games but denied that special routes reserved for Olympic traffic would cause problems.
"Any talk of transport arrangements being chaotic is very wide of the mark. The Olympic route network will cover just 1% of the roads," he said.
"I will bust another myth - taxis and public buses will use the majority of the Olympic route network. We will ensure that London keeps working."
He said £6.4bn was being spent on improving transport ready for the Games.
Olympics Minister Hugh Robertson also took part in the presentation and said the UK government was confident it could deliver "a safe and secure Games".
'Nuts and bolts'
IOC president Jacques Rogge praised London's progress.
He said: "The nuts and bolts are in place and we have no doubt the operational issues will be delivered in due time.
"We are thrilled by the success of the sale of tickets. It's something unheard of and proves the great love of sport, not just among British people, but also overseas among the 205 countries."
The chance to buy more than 1.5 million unsold Olympic tickets opens on Friday at 0600 BST to the 700,000 applicants who got all or part of their ticket requests in the first-round of sales which closed in April.
This window, for tickets across 58 sessions and 130 price categories, runs until 1800 BST on 17 July.
There are about 1.5 million football tickets, 40,000 volleyball and 8,000 freestyle wrestling tickets available on a first-come first-served basis.
The football includes men's and women's matches at Wembley Stadium, City of Coventry Stadium, Millennium Stadium, Hampden Park, St James' Park and Old Trafford.