NEW YORK (Reuters) - A stolen copy of the new Harry Potter novel may already have surfaced in Britain, but the book's American publisher is confident the latest tale of the boy wizard's adventures will be kept secret, at least on this side of the Atlantic, until next month's publication.

Barbara Marcus, president of Children's Book Publishing at Scholastic -- author J.K. Rowling's U.S. publisher -- said 10.8 million copies of "Harry Potter and the Half-Blood Prince" had been printed.

Most them will be in bookstores on July 16, with some held in reserve for restocking.

In an interview at the Book Expo America trade fair in New York, Marcus said security was tight but Scholastic was relying on booksellers to make sure there are no leaks or early sales.

"They really know what their responsibility is. The only thing we hold over people's heads is that we say we can't ship any more books," she said, noting that the threat of being cut off from future supplies was keeping booksellers from breaking the rules.

"Everybody wants to be able to put this book in the hands of the children," she said.

Marcus spoke shortly before news emerged that two Britons had been charged with firearms offenses on Saturday after reportedly trying to sell a stolen copy of the new Harry Potter book to the London tabloid the Sun for nearly $91,000.

The latest book is the sixth installment in the hugely popular series about the boy wizard and his friends. The fifth adventure, published in 2003, made publishing history, selling 5 million copies within 24 hours. Pre-orders have already made the new book the top seller on Amazon.

Marcus said she was one of just a handful of people who had read the book, including the editors responsible for Americanizing the text.

"I would say definitely fewer than 10 people have read it," said Marcus, who bought the American rights to the series for $105,000 back in 1997. She said it seemed like a lot of money at the time "for an unpublished first book by an unknown British writer."

Scholastic has sold 103 million copies of the previous five Harry Potter books and is providing promotional material for bookshops around the country which plan to hold midnight parties for fans to buy the book the moment it goes on sale.

"The booksellers have taken control and I would say there are going to be thousands and thousands of midnight parties at 12.01 on July 16," Marcus said.

She declined to give away much about the new book, beyond repeating a few snippets that Rowling has already revealed.

"There's a new minister of magic, someone dies but it's not Harry or Voldemort, and the half blood prince is not Harry or Voldemort," she said.

Source: http://news.yahoo.com/news?tmpl=story&u=/nm/20050605/us_nm/arts_potter_dc_1