Some 6.6 million tickets are available from the London 2012 website over a six-week period and organisers say all applications will be treated equally.

Prices range from £20 to £2,012 and oversubscribed events will be decided by a ballot. Half a billion pounds is forecast to be raised from ticket sales.

The ticket website initially failed to process the orders of people whose Visa card expires before August.

Organisers said they were confident they had done everything they could to avoid the website crashing as people log on for the first time to buy tickets.

Several events will be free, such as the marathon, and 2.5 million tickets will be available for £20 and under. Others start at between £30 and £50.

Children under 17 will be able to "pay-your-age" to see some of the early heats, while the over-60s can watch for £16 at the same events.

Some 75% - or 6.6 million - of the 8.8 million tickets are available to the general public via the application process. Of the remaining 2.2 million tickets, roughly half will be issued to National Olympic Committees (NOC) of each country, and half will be split between sponsors, the IOC, guests and hospitality partners.

People from some European countries can apply through the London 2012 website but residents of other countries must apply through their National Olympic Committee or appointed authorised ticket reseller.

A further two million tickets for the Paralympic Games go on sale on September 9.

There has been some criticism of the ticket-buying process as all online tickets can be only paid for with a Visa card.