Dion took a break from showbusiness to prepare for the shows

The singer will perform about 600 concerts at the famous Caesar's Palace Hotel with her stint not due to end until 2006.

The show was launched with a star-studded premi�re but the celebrations were dampened because of the war in Iraq, with the after-show party being cancelled.

The show, entitled A New Day, is being staged in a purpose-built theatre which seats 4,100 people.

Dion will share the stage with 48 glamorously-costumed dancers, three backing singers and eight musicians.

During the show Dion sings some of her most famous hits, including The Power of Love, as well as classics by artists such as Frank Sinatra.

Dion is being paid a reported $100m (�66m) for five 90-minute concerts a week in the gambling city.

"I feel like I'm inviting my fans to my home," she told USA Today newspaper.

Dion shares the stage with 48 dancers

"For years people have been kind enough to welcome me into their cities and towns.

"I feel like, OK, now its time for me to invite you to my place."

Tickets went on sale 10 months ago and some 250,000 have already been reserved.

To prepare for the gruelling run Dion took a two-year break from showbusiness to spend time with her husband and manager Rene Angelil.

The couple had their first baby, Rene-Charles, in 2001.

Among those wishing Dion luck with her marathon shows were Catherine Zeta Jones and Michael Douglas, who took out an advertisement in Variety trade magazine wishing her well.