The global sensation composed by Britain's Andrew Lloyd Webber was due to open at the Mogador theatre in Paris on October 13.
But a blaze that started under the stage of the Mogador on Sunday morning has thrown the plan into doubt, the theatre's management said in a statement. A fireman was injured bringing the fire under control.
A superstition has grown up over the years among theatre-makers and audiences that performances of "Phantom" are somehow cursed -- in much the same way that actors shy away from uttering the name of Shakespeare's
In 1896 a chandelier counterweight fell from the ceiling killing a patron at the Paris Opera House, inspiring Gaston Leroux to write the novel on which the "Phantom" musical is based.
The fire on Sunday damaged scenery for the upcoming production, along with part of the theatre's floor, the Mogador said.
"(It is) difficult to estimate the time needed for the repairs at the moment," its statement said. "We will probably know tomorrow if we will need to delay the performance," the theatre's director Laurent Bentata told AFP.
The cause of the fire is still unknown.
"The Phantom of the Opera", which had its world premiere at Her Majesty's Theatre in London in 1986, is the most lucrative theatre venture of all time, grossing a reported $5.6 billion worldwide.