July 17 (Bloomberg) -- Scholastic Corp., the U.S. publisher of the Harry Potter books, said the sixth J.K. Rowling novel about a boy wizard and the fantasy world he inhabits sold a record 6.9 million copies in the first 24 hours as thousands of fans packed stores to await the book's midnight release.

Scholastic said it published a record 10.8 million copies of ``Harry Potter and the Half-Blood Prince'' in its first printing and rushed a second printing of 2.7 million copies as retailers reported heavy advance orders. The fifth installment sold more than 5 million copies in the first 24 hours.

Barnes & Noble, Borders Group Inc. and Books-A-Million Inc., the top three U.S. bookstore chains, were among retailers holding parties to celebrate the book's release at 12:01 a.m. yesterday. All three chains expect to set sales records. Scholastic said there were more than 5,000 midnight parties.

About 500,000 fans flocked to Borders Friday night and more than 850,000 copies of Harry Potter were sold, beating the record of 750,000 set by the previous title, ``Harry Potter and the Order of the Phoenix,'' in summer 2003, Ann Arbor, Michigan-based Borders said in a statement.

``These Harry Potter titles have each been a record, probably going back to the first Harry Potter book,'' Borders spokeswoman Anne Roman said in a telephone interview. ``This is pretty much in line with our expectations.''

Fans began lining up outside a Borders store in Puyallup, Washington, July 14, and a store in Singapore stayed open for 39 hours straight to allow shoppers to get a copy of the 672-page book.

Internet retailer Amazon.com Inc. got 1.5 million advance orders, its largest ever, and almost 7.7 percent more than it got for ``Order of the Phoenix.'' Barnes & Noble took more than 1 million advance orders, exceeding the 896,000 Potter books sold in the first day in 2003.

To contact the reporter on this story: Chris Dolmetsch in Princeton at cdolmetsch@bloomberg.net.

Last Updated: July 17, 2005 17:30 EDT