First novel tipped to be Hollywood blockbuster

She wrote it amid bouts of morning sickness and the daily chores of family life. Now the married mother-of-three who completed her first novel while heavily pregnant is poised to become a millionaire after selling the rights world-wide for a "substantial" six-figure sum.

Katy Gardner, 37, a part-time university lecturer, has signed an international two-book deal with Penguin after a bidding war between 10 rival publishers. Her novel, Losing Gemma, which has already been sold to 15 countries, is being tipped to top the bestseller list and be turned into a major Hollywood film.

Acclaimed by critics as a successful fusion of the "chick lit" genre spawned by Bridget Jones's Diary and "backpacker" fiction such as Alex Garland'sThe Beach, the book was inspired by Miss Gardner's own travels. An edgy psychological thriller, it focuses on the mystery surrounding the fate of a young woman who vanishes while travelling with a friend in India.

Miss Gardner, who had several academic texts to her name before turning to fiction, wrote the bulk of Losing Gemma while on maternity leave expecting her third child.

"It was a labour of love," she said. "By the time I got around to writing this book I had already had two other novels rejected. The second one was nearly sold, but I couldn't get the ending right. After that, I thought, 'let's just try one more time'. Fortunately, my agent was very encouraging, and I became very bull-headed about it."

On the face of it, Losing Gemma contains some classic "chick-lit" ingredients, including a glamorous leading lady who bears the same first name as the author of another celebrated travel novel, Hideous Kinky by Esther Freud.

However, Miss Gardner, a social anthropology lecturer at Sussex University, is adamant that the story owes more to her time studying rural life in Bangladesh than to tales of man-eating north London socialites. "There's a danger that any book written by a woman about women is going to be labelled 'chick lit', but this book is nothing to do with the search for Mr Right, worrying about weight, or drinking chardonnay."

The speed with which Losing Gemma was snapped up has already enabled Miss Gardner and partner Graham Alborough, 43, a TV scriptwriter, to set about buying a bigger house. They are in the final stages of selling their three-bedroom home in Brighton and will soon be moving with their children, Lauren, six, Carey, three, and Gabriel, one, to a cottage in the Sussex countryside.

Miss Gardner's agent, Clare Conville, described the response to Losing Gemma as "extraordinary", and confirmed that deals already in place would net its author "not far off" £1m. "The book was accepted by the first publisher it was sent to, and I had nine or 10 others who wanted to bid on it," she said. "Normally, a very successful book would get maybe five or six bids. We've sold the international rights very quickly. The book's been getting great reviews here, and the buzz I've had from foreign publishers has been very positive."

Ms Conville added that she had had "endless" calls from film producers at home and abroad who were keen to option the novel, which in the US is the Boston Herald's Book of the Month. However, she was "sitting back" until she received an offer from a studio with the clout to turn it into a sufficiently big-budget movie.