Advertisement is betting that an uncommon length of reading material — longer than a magazine article but shorter than a book — will be a popular format in electronic form for its Kindle e-book reader.

The online retailer said Tuesday it is launching Kindle "Singles," a section of its electronic bookstore dedicated to pieces that are 10,000 to 30,000 words or 30 to 90 pages.

Amazon said that is about twice the length of an article in The New Yorker or several chapters of a book.

And the company said it is soliciting the pieces outside of the publishing industry.

"Today's announcement is a call to serious writers, thinkers, scientists, business leaders, historians, politicians and publishers to join Amazon in making such works available to readers around the world," the company said.

It said "interested parties" should contact

Amazon did not immediately respond to an inquiry about how much the "Singles" would cost.

The news comes as Amazon's tries to keep its Kindle reader in the dominant position in the e-reader market.

It faces competition Apple Inc.'s iPad and other similar dedicated reading devices such as Barnes & Noble Inc.'s Nook.

In January, Amazon said it planned to offer do-it-yourself authors and publishers royalties of about 70 percent on their e-books if they use its e-book self-publishing program, the Kindle Digital Text Platform and meet certain criteria.

Amazon shares rose $1.89 to $154.92 during afternoon trading.