Amazon will introduce two new versions of its Kindle electronic reader on Thursday, including a model that sells for 139 dollars, its lowest price yet, The New York Times reported.

The 139-dollar Kindle will be Wi-Fi only, connecting to the online Kindle store by wireless instead of 3G cellular networks like the previous Kindles, the Times said.

The other new Kindle will replace the basic Kindle 2, which was listed as "temporarily out of stock" on Wednesday at Amazon.com.

The Times said the new basic Kindle will sell for the same price, 189 dollars, as the current model.

It said both new Kindles are smaller and lighter than the current versions and feature higher resolution screens and crisper text.

Amazon is cutting the price of the Kindle and revamping the line as it faces a threat in the e-reader market from Apple's iPad and companies like Sony and bookstore Barnes & Noble, which also offer e-readers.

"The hardware business for us has been so successful that we're going to continue," Amazon founder and chief executive Jeff Bezos told the Times in an interview.

"I predict there will be a 10th-generation and a 20th-generation Kindle. We're well-situated to be experts in purpose-built reading devices," he said.

Bezos said not to expect a color Kindle soon. Color was "not ready for prime time," he said.

Apple's cheapest iPad costs 499 dollars and features a color e-reader compared with the black-and-white Kindle, which is devoted exclusively to digital books.

Barnes & Noble sells a version of its e-reader, the Nook, for 149 dollars while Sony's cheapest e-reader is 150 dollars.

The new Kindles, which will ship on August 27, weigh about 15 percent less and are 21 percent smaller than the current basic model, the Times said.

Amazon's also offers a large-screen model, the Kindle DX, which costs 379 dollars.

Amazon does not release sales figures for the Kindle, but says it has been the Seattle, Washington-based company's bestselling item for two years.