Harry Potter hasn't lost a bit of his magic.

The sixth book about the boy wizard, "Harry Potter and the Half-Blood Prince," has sold more than 11 million copies since its U.S. release July 16, publisher Scholastic says.

The book also is selling at a faster pace than its predecessors. The fifth installment, "Harry Potter and the Order of the Phoenix," took an additional three weeks to achieve the same sales total.

In addition, "Half-Blood Prince" sold 6.9 million copies in the first 24 hours, making it the fastest-selling book ever. The record had been held by "Order of the Phoenix," which sold 5 million copies in its first day in 2003.

Author J.K. Rowling expects to begin writing the seventh and final Harry Potter book as early as the end of this year. It should land in bookstores in about two years.