She's known to have quite the interest in the sport, and Pippa Middleton was front row at the O2 Arena in London, England for the Barclays ATP World Tour Finals on Sunday (November 27).

Looking chic in a bright blue ensemble, the sister of the Duchess of Cambridge was alongside a few friends as she watched the final match between Jo-Wilfried Tsonga and Roger Federer.

The annual event which sees the top 8 players gathered to compete in the year-end championships ended up being claimed by Federer, who won a close contest by a final tally of 6-3, 6-7, 6-3.

Meanwhile, reports tell that Miss Middleton has been the subject of a fierce bidding war by some of Britain’s largest publishers for her first book.

Most recently, an insider at Telegraph tells that publisher Michael Joseph of Penguin books signed her up to a publishing deal worth $618,000 last week - though nothing has been confirmed.

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