Pippa Middleton
Pippa Middleton (pictured) is set to publish a book on how to be the perfect party hostess. It will include recipes, anecdotes and details of how to throw a variety of events. REUTERS

Pippa Middleton has signed a six-figure publishing deal to write a guide to party planning.

After being at the centre of an intense bidding war by some of Britain's largest publishers for her first book, Pippa is understood to have signed a deal worth £400,000 with Michael Joseph, an imprint of Penguin books.

The 28-year-old's literary agent, David Godwin, is said to have sealed the book deal last week.

According to a report in The Telegraph, industry sources said the negotiating process involved detailed discussions about the book's timing, which is due to be released in time for Christmas next year.

The book is not due to launch until after the Queen's Diamond Jubilee celebrations next summer to ensure that the sister of the Duchess of Cambridge is not seen to be cashing in on her royal connections.

While the younger Middleton sister is keen for the book to be released next year, she is determined not to be seen as making money from her closeness to the royal family. The book is therefore not likely to be released until late next autumn, well after the summer Jubilee celebrations but in time for the Christmas market.

"She wanted to publish it next year, but it will be timed to come out after the Jubilee," said one book industry insider.

The book will be a guide to being the perfect party hostess. It will include recipes, anecdotes and details on how to throw a variety of events.

Pippa's experience as a professional party-planner at the London-based company Table Talk, and her regular contributions to the online newsletter of her parent's firm, The Party Times, places her in a perfect position to write an authoritative book.

According to Michael Joseph's website, they publish "highly commercial, popular fiction and non-fiction, principally interested in publishing Top Ten bestsellers". Published authors on their non-fiction list include Jamie Oliver and Jeremy Clarkson, as well as Ant and Dec.

Harper Collins and Cornerstone, a branch of Random House, were among other publishers also said to be keen on the book.