PARIS - France's First Lady Carla Bruni said on Tuesday she had cancelled a red-carpet appearance at the Cannes film festival because of "personal reasons", feeding rumours that she might be pregnant.

Bruni, a former supermodel who married French President Nicolas Sarkozy three years ago, played a small role in US director Woody Allen's movie "Midnight in Paris" which opens this year's festival on France's Cote d'Azur.

Bruni said she would not be able to attend Wednesday's opening for both personal and professional reasons.

In recent weeks, Bruni has fanned media rumours that she is expecting by evading questions and saying that she does not want to talk because she has something to protect.

When asked on RTL radio, she again declined to comment, saying that it was a "private question".

"I want to protect my private and family life," said Bruni, who has often stated she would like to have a child with Sarkozy, who she married after he became president in 2007.

A pregnancy would be a public relations boon for the first couple as Sarkozy struggles to revive his sagging popularity ratings a year ahead of a presidential election.

Political commentators say a pregnancy could boost the image of the presidential couple among the French, many of whom dislike Sarkozy's flashy image and found his public courtship of Bruni, who has launched a career as a pop singer, in bad taste.