Madonna is going to 'turn the world into one big dancefloor'

The tour, which starts on 21 May, is full in several venues, including seven shows at London's Wembley Arena, according to US magazine Billboard.

Other sold-out shows in her tour include dates in Paris, Amsterdam, Las Vegas, Phoenix, San Jose and Montreal.

The Confessions on a Dancefloor tour is named after Madonna's number one album.

Ticket auction

The album topped the charts on its debut in 29 countries and spawned two number one singles in the UK.

In 2004, her Re-Invention tour grossed $125m (�71.7m) and drew more than 900,000 fans to 56 shows.

The singer sold out 55 of the shows, making about $2.23m (�1.28m) a night, Billboard reported.

So far, Madonna has announced 40 shows in 21 venues across the US, Canada and Europe, in her latest tour, with many already sold out.

Fans who have missed out on tickets can bid for the best seats at selected shows in the US.

They are being officially sold by auction over the next seven days, with bids for her opening Los Angeles date reaching $1,060 (�608) for a pair after less than a day on sale.