French President Nicolas Sarkozy and his wife Carla Bruni

In a newly published book, France's first lady speaks out about falling head over heels in love with President Nicolas Sarkozy, not only for his "physique", but also for his "five or six brains".

Carla Bruni-Sarkozy has maintained a relatively low profile since her whirlwind romance with Sarkozy culminated in marriage in February, but she finally lifts the curtain on their relationship in "Carla and Nicolas, the real story."

"It all happened suddenly. I wasn't expecting someone so funny, so full of life. I was seduced by his physique, his charm and his intelligence," she tells the book's authors.

"He has five or six brains which are remarkably irrigated," the former supermodel said, adding that Sarkozy could process what others around him were saying while reading at the same time no matter how late it was.

The book tracks the events of the most talked about French love story in years, showing how the 39-year-old singer suspected she was being set up for a blind date after Sarkozy asked a friend to organise a dinner in November.

"In fact, I realised when I arrived that it was a blind date. A blind date not so blind," she said. "There were three couples and us two, two single people."

Sarkozy only had eyes for her during the dinner and escorted her home in the early hours of the morning. He returned to her house the next day for a candlelight dinner, the book says.

Turning to her life as first lady, Bruni-Sarkozy said she had no intention of ditching her singing career.

"I have no intention to change job. I have a function, but it is not a job," she said, adding that she had inherited her function through marriage.

Besides working on her next album, which is due out on July 21, Carla said she would look to support her husband:

"I often worry about him. He works unbelievably hard. I try to help him take it easy."