Research In Motion ( BBRY - Analyst Report ) is facing a setback in its effort to revamp its falling smartphone market. This is because the third largest US telecom carrier Sprint Nextel Corporation ( S - Analyst Report ) has denied addition of the smartphone manufacturer’s latest BB10 OS (Operating System) based device in its portfolio. Sprint has instead agreed to add the Qwerty based version in its line up when the device comes up for sale later this year.

Sprint’s decision will make it the only top tier U.S. carrier not to have BlackBerry’s latest flagship smartphone Z10 in its stable. Research in Motion has all the other three U.S. carriers as its partner, with agreement to sell both the BB10 based devices from its stable.

Research In Motion, once the global leader of smartphones, has been struggling since the last 3-4 years, as they failed to identify consumers’ preferences and has been battling in a crowded smartphone market mainly dominated by Apple Inc.’s ( AAPL - Analyst Report ) iOS and Google Inc.’s ( GOOG - Analyst Report ) Android Platform.

In a last gasp attempt to revive its fortunes the Canadian handset manufacturer launched two BB10 based device on Jan 30, 2013. The newly launched Blackberry Z10 is a full touch screen smartphone while BlackBerry Q10 includes both touch and physical keyboard options.

The company started selling Z10 in the United Kingdom last month and since then has expanded in over 50 markets around the world. Research in Motion has seen robust demand for its flagship device in some of the markets including U.K., Canada and U.A.E. Moreover, they are witnessing strong customer switch from other OS platforms for their latest BB10 based device.

However, the company has declared that Q10 will not be available in the US until next month as it is currently undergoing carrier testing. This signifies that a Sprint customer will have to wait for some more time before they can get their hands on the latest BlackBerry device.

According to research firm comScore Inc. at the end of 2012 Research In Motion has 6.4% of the U.S. market while Google’s Android and Apple’s iOS commands 53.4% and 36.3% market share respectively. We believe that the company needs strong carrier support in the lucrative U.S. market if it wants to establish itself as the third operating system alternative.

Currently, Research In Motion carries a Zacks Rank # 3 (Hold).