Amazon is set to release two new models of its popular e-book reader, the Kindle, according to the TechCrunch blog.

An "insider" told TechCrunch that one model, a smaller, updated version with an improved interface, would be available as early as October in time for the holiday season. The source also said that Amazon has "skipped three or four generations," and compared the old Kindle to the first-generation iPod and the new version to the sleeker iPod Mini.

TechCrunch said the second new model, which should be available next year, is shaped like a 8 1/2-inch by 11-inch sheet of paper and is much bigger than the current model, which is the size of a paperback book.

Both models will most likely come in a variety of colors and may be aimed at younger readers, according to TechCrunch.

Amazon could not be reached for comment.

Although Amazon has refused to release the numbers of Kindles sold, the company has said the original Kindle, which first went on sale Nov. 19, sold out in five and a half hours. From that date until sometime this past spring, Amazon said it had a hard time keeping up with the demand for the device.

The Kindle allows users to wirelessly download books, newspapers, magazines and blogs. The reader, which costs US$399, is the size of a paperback book and weighs 10.3 oz. The device uses electronic paper, a high-resolution display technology that provides a sharp black-and-white screen that's as easy to read as printed paper, the company said. Kindle uses Sprint's high-speed data network (EV-DO) for its wireless broadband connection.