Amazon.com Inc.'s (AMZN) decision to switch to AT&T Inc. (T) as the wireless provider for its newest Kindle is a blow to Sprint Nextel Corp. (S), which could be left as a jilted partner for future e-reader models.

The Kindle has long been Sprint's high-profile model for its connected devices business, which provides wireless service to products that aren't phones.

While revenue from the deal wasn't significant, Sprint Chief Executive Dan Hesse would often point to it in his claim that the carrier was a leader in the area. But the company's larger rivals have been pushing hard to establish their own foothold in the business, signing buzz-worthy partnerships of their own.

On Wednesday, Amazon.com unveiled a new Kindle with international access, which uses a global standard called GSM that is powered by AT&T. The online retailer also cut the price of its older Kindle - which uses Sprint's service - by $40 to $259. Existing Kindles will continue to use Sprint's service, but it's unclear what their relationship will be like for future devices.

AT&T has a "long-term strategic agreement" to power the Kindle, according to Glenn Lurie, head of the company's emerging devices business.

Sprint continues to have "strategic discussions on an ongoing basis" with Amazon.com, said Danny Bowman, who similarly oversees Sprint's connected devices business.

Amazon.com declined to comment on its future Kindle plans.

The expansion to global access is a natural move by Amazon.com because Kindle users are typically more sophisticated and are more likely to travel overseas. As the user base has grown, so have the demands on the e-reader. Amazon.com's decision to use AT&T and its broader access to the international network underscores the domestic limitation of Sprint.

"Device manufacturers are certainly increasingly conscious of maximizing their addressable market," said Daniel Hays, telecom analyst at the consulting firm PRTM. "As such, most of them are trying to go with network technologies that are most widely utilized."

The opportunity to connect multiple devices - from digital cameras to residential power meters - is a hot topic at the CTIA wireless industry trade show. Ahead of the show, which began Wednesday, Sprint said it had created a unit focused on the area. A few months ago, Verizon Wireless - jointly owned by Verizon Communications Inc. (VZ) and Vodafone Group Plc (VOD) - formed a joint venture with Qualcomm Inc. (QCOM) to foster the development of connected devices.

The market is still in its infancy, so there remains for the players to each grow. But Kindle's decision to switch underscores the increasing competition in the area.

"Are we going to bump into each other? Of course we are," Lurie said.

In many cases, global access may be an advantage that AT&T has over Sprint, as well as Verizon Wireless, which uses the same network technology as Sprint.

"Many [original equipment manufacturers] will want to bet on a device that works around the world," Lurie said.

Sprint, however, has lower operating costs, and does have an opportunity to target low-cost devices that don't need to go overseas. Earlier Thursday, the company said it would begin offering a service that would allow businesses such as cable providers or smaller traditional telephone companies to more easily run a wireless resale business under their own brands.

The company said the offering, in which Sprint would handle many of the back office tasks that have plagued resellers in the past, would remove the historical barriers to entry to the wireless business.

Bowman acknowledged that Sprint's rivals had done a better job in recent months of touting their flashy partnerships. He predicted the company would have a number of "exciting" partnerships of its own to announce in the coming months.

"It's about doing a better job of getting our name out," he said.

-By Roger Cheng, Dow Jones Newswires; 212-416-2153; roger.cheng@dowjones.com