An 18-year-old author has received a ￡400,000 advance for her debut novel, one of the biggest deals for a young author in British publishing history.

Helen Oyeyemi, a first-year student at Corpus Christi College, Cambridge, is now in the top bracket of British authors and shares an accountant with J. K. Rowling and Zadie Smith.

Ms Oyeyemi struck a two-book deal with Bloomsbury after the publisher was bowled over by her novel The Icarus Girl. The story concerns Jessamy, an eight-year-old genius who, while on a visit to relatives in Nigeria, meets Tilly Tilly, a friend whom only she can see.

Their relationship is friendly at first but becomes darker as it appears that Tilly Tilly is a ghost who wants Jessamy's body for her own.

In an interview, the Nigerian-born author said that she was astonished at the speed with which she was snapped up. "I had to sign the contract between my exams. It was on the day of my theology A level," she said.

Ms Oyeyemi, whose father is a teacher and whose mother is training to become a driver for London Underground, began writing at the age of seven.

"I rewrote Little Women so that Laurie married Jo because I thought that was a better ending."

She began writing The Icarus Girl last year when she was in the sixth form of Notre Dame School. Her agent, Robin Wade, showed the book to Alexandra Pringle, editor-in-chief at Bloomsbury, who is also Donna Tartt's editor. "The prose sings immediately right from the first page," Ms Pringle said.

Ms Oyeyemi does not believe that she will become a full-time writer, however. "I don't think that many people can do that these days," she said. "I would quite like to be a literary agent."

(Agencies)