User blog comment:Menara/The Mark of Athena Character Art Revealed!/@comment-3498371-20120909144818/@comment-3146930-20120910022406

Disney has always owned Hyperion Books as far as I know. Hyperion Books is a publishing company, so they edit the books, print the books, and pretty much schedule his book tours. But they are still owned by Disney. The Disney site set up the Heroes of Olympus page as the series is targeted for younger readers and is very popular. They are the ones that release character art and the descriptions, as well as chapter previews and stuff. So basically Disney is in charge of marketing and Hyperion Books is in charge of making sure the book is released on time and printing. If you liked the series before, nothing has changed from the time it was started.